THE CRAIG KENNEDY SERIES

As I look back now on the sensational events of the past months since the great European War began, it seems to me as if there had never been a period in Craig Kennedy’s life more replete with thrilling adventures than this.

In fact, scarcely had one mysterious event been straightened out from the tangled skein, when another, even more baffling, crowded on its very heels.

As was to have been expected with us in America, not all of these remarkable experiences grew either directly or indirectly out of the war, but there were several that did, and they proved to be only the beginning of a succession of events which kept me busy chronicling for the Star the exploits of my capable and versatile friend.

Altogether, this period of the war was, I am sure, quite the most exciting of the many series of episodes through which Craig has been called upon to go. Yet he seemed to meet each situation as it arose with a fresh mind, which was amazing even to me who have known him so long and so intimately.

As was naturally to be supposed, also, at such a time, it was not long before Craig found himself entangled in the marvelous spy system of the warring European nations. These systems revealed their devious and dark ways, ramifying as they did tentacle-like even across the ocean in their efforts to gain their ends in neutral America. Not only so, but, as I shall some day endeavor to show later, when the ban of silence imposed by neutrality is raised after the war, many of the horrors of the war were brought home intimately to us.

I have, after mature consideration, decided that even at present nothing but good can come from the publication at least of some part of the strange series of adventures through which Kennedy and I have just gone, especially those which might, if we had not succeeded, have caused most important changes in current history. As for the other adventures, no question can be raised about the propriety of their publication.

At any rate, it came about that early in August, when the war cloud was just beginning to loom blackest, Kennedy was unexpectedly called into one of the strangest, most dangerous situations in which his peculiar and perilous profession had ever involved him.

CHAPTER I
THE WAR TERROR

“I must see Professor Kennedy—where is he?—I must see him, for God’s sake!”

I was almost carried off my feet by the inrush of a wild-eyed girl, seemingly half crazed with excitement, as she cried out Craig’s name.

Startled by my own involuntary exclamation of surprise which followed the vision that shot past me as I opened our door in response to a sudden, sharp series of pushes at the buzzer, Kennedy bounded swiftly toward me, and the girl almost flung herself upon him.

“Why, Miss—er—Miss—my dear young lady—what’s the matter?” he stammered, catching her by the arm gently.

As Kennedy forced our strange visitor into a chair, I observed that she was all a-tremble. Her teeth fairly chattered. Alternately her nervous, peaceless hands clutched at an imaginary something in the air, as if for support, then, finding none, she would let her wrists fall supine, while she gazed about with quivering lips and wild, restless eyes. Plainly, there was something she feared. She was almost over the verge of hysteria.

She was a striking girl, of medium height and slender form, but it was her face that fascinated me, with its delicately molded features, intense unfathomable eyes of dark brown, and lips that showed her idealistic, high-strung temperament.

“Please,” he soothed, “get yourself together, please—try! What is the matter?”

She looked about, as if she feared that the very walls had eyes and ears. Yet there seemed to be something bursting from her lips that she could not restrain.

“My life,” she cried wildly, “my life is at stake. Oh—help me, help me! Unless I commit a murder to-night, I shall be killed myself!”

The words sounded so doubly strange from a girl of her evident refinement that I watched her narrowly, not sure yet but that we had a plain case of insanity to deal with.

“A murder?” repeated Kennedy incredulously. “You commit a murder?”

Her eyes rested on him, as if fascinated, but she did not flinch as she replied desperately, “Yes—Baron Kreiger—you know, the German diplomat and financier, who is in America raising money and arousing sympathy with his country.”

“Baron Kreiger!” exclaimed Kennedy in surprise, looking at her more keenly.

We had not met the Baron, but we had heard much about him, young, handsome, of an old family, trusted already in spite of his youth by many of the more advanced of old world financial and political leaders, one who had made a most favorable impression on democratic America at a time when such impressions were valuable.

Glancing from one of us to the other, she seemed suddenly, with a great effort, to recollect herself, for she reached into her chatelaine and pulled out a card from a case.

It read simply, “Miss Paula Lowe.”

“Yes,” she replied, more calmly now to Kennedy’s repetition of the Baron’s name, “you see, I belong to a secret group.” She appeared to hesitate, then suddenly added, “I am an anarchist.”

She watched the effect of her confession and, finding the look on Kennedy’s face encouraging rather than shocked, went on breathlessly: “We are fighting war with war—this iron-bound organization of men and women. We have pledged ourselves to exterminate all kings, emperors and rulers, ministers of war, generals—but first of all the financiers who lend money that makes war possible.”

She paused, her eyes gleaming momentarily with something like the militant enthusiasm that must have enlisted her in the paradoxical war against war.

“We are at least going to make another war impossible!” she exclaimed, for the moment evidently forgetting herself.

“And your plan?” prompted Kennedy, in the most matter-of-fact manner, as though he were discussing an ordinary campaign for social betterment. “How were you to—reach the Baron?”

“We had a drawing,” she answered with amazing calmness, as if the mere telling relieved her pent-up feelings. “Another woman and I were chosen. We knew the Baron’s weakness for a pretty face. We planned to become acquainted with him—lure him on.”

Her voice trailed off, as if, the first burst of confidence over, she felt something that would lock her secret tighter in her breast.

A moment later she resumed, now talking rapidly, disconnectedly, giving Kennedy no chance to interrupt or guide the conversation.

“You don’t know, Professor Kennedy,” she began again, “but there are similar groups to ours in European countries and the plan is to strike terror and consternation everywhere in the world at once. Why, at our headquarters there have been drawn up plans and agreements with other groups and there are set down the time, place, and manner of all the—the removals.”

Momentarily she seemed to be carried away by something like the fanaticism of the fervor which had at first captured her, even still held her as she recited her incredible story.

“Oh, can’t you understand?” she went on, as if to justify herself. “The increase in armies, the frightful implements of slaughter, the total failure of the peace propaganda—they have all defied civilization!

“And then, too, the old, red-blooded emotions of battle have all been eliminated by the mechanical conditions of modern warfare in which men and women are just so many units, automata. Don’t you see? To fight war with its own weapons—that has become the only last resort.”

Her eager, flushed face betrayed the enthusiasm which had once carried her into the “Group,” as she called it. I wondered what had brought her now to us.

“We are no longer making war against man,” she cried. “We are making war against picric acid and electric wires!”

I confess that I could not help thinking that there was no doubt that to a certain type of mind the reasoning might appeal most strongly.

“And you would do it in war time, too?” asked Kennedy quickly.

She was ready with an answer. “King George of Greece was killed at the head of his troops. Remember Nazim Pasha, too. Such people are easily reached in time of peace and in time of war, also, by sympathizers on their own side. That’s it, you see—we have followers of all nationalities.”

She stopped, her burst of enthusiasm spent. A moment later she leaned forward, her clean-cut profile showing her more earnest than before. “But, oh, Professor Kennedy,” she added, “it is working itself out to be more terrible than war itself!”

“Have any of the plans been carried out yet?” asked Craig, I thought a little superciliously, for there had certainly been no such wholesale assassination yet as she had hinted at.

She seemed to catch her breath. “Yes,” she murmured, then checked herself as if in fear of saying too much. “That is, I—I think so.”

I wondered if she were concealing something, perhaps had already had a hand in some such enterprise and it had frightened her.

Kennedy leaned forward, observing the girl’s discomfiture. “Miss Lowe,” he said, catching her eye and holding it almost hypnotically, “why have you come to see me?”

The question, pointblank, seemed to startle her. Evidently she had thought to tell only as little as necessary, and in her own way. She gave a little nervous laugh, as if to pass it off. But Kennedy’s eyes conquered.

“Oh, can’t you understand yet?” she exclaimed, rising passionately and throwing out her arms in appeal. “I was carried away with my hatred of war. I hate it yet. But now—the sudden realization of what this compact all means has—well, caused something in me to—to snap. I don’t care what oath I have taken. Oh, Professor Kennedy, you—you must save him!”

I looked up at her quickly. What did she mean? At first she had come to be saved herself. “You must save him!” she implored.

Our door buzzer sounded.

She gazed about with a hunted look, as if she felt that some one had even now pursued her and found out.

“What shall I do?” she whispered. “Where shall I go?”

“Quick—in here. No one will know,” urged Kennedy, opening the door to his room. He paused for an instant, hurriedly. “Tell me—have you and this other woman met the Baron yet? How far has it gone?”

The look she gave him was peculiar. I could not fathom what was going on in her mind. But there was no hesitation about her answer. “Yes,” she replied, “I—we have met him. He is to come back to New York from Washington to-day—this afternoon—to arrange a private loan of five million dollars with some bankers secretly. We were to see him to-night—a quiet dinner, after an automobile ride up the Hudson—”

“Both of you?” interrupted Craig.

“Yes—that—that other woman and myself,” she repeated, with a peculiar catch in her voice. “To-night was the time fixed in the drawing for the—”

The word stuck in her throat. Kennedy understood. “Yes, yes,” he encouraged, “but who is the other woman?”

Before she could reply, the buzzer had sounded again and she had retreated from the door. Quickly Kennedy closed it and opened the outside door.

It was our old friend Burke of the Secret Service.

Without a word of greeting, a hasty glance seemed to assure him that Kennedy and I were alone. He closed the door himself, and, instead of sitting down, came close to Craig.

“Kennedy,” he blurted out in a tone of suppressed excitement, “can I trust you to keep a big secret?”

Craig looked at him reproachfully, but said nothing.

“I beg your pardon—a thousand times,” hastened Burke. “I was so excited, I wasn’t thinking—”

“Once is enough, Burke,” laughed Kennedy, his good nature restored at Burke’s crestfallen appearance.

“Well, you see,” went on the Secret Service man, “this thing is so very important that—well, I forgot.”

He sat down and hitched his chair close to us, as he went on in a lowered, almost awestruck tone.

“Kennedy,” he whispered, “I’m on the trail, I think, of something growing out of these terrible conditions in Europe that will tax the best in the Secret Service. Think of it, man. There’s an organization, right here in this city, a sort of assassin’s club, as it were, aimed at all the powerful men the world over. Why, the most refined and intellectual reformers have joined with the most red-handed anarchists and—”

“Sh! not so loud,” cautioned Craig. “I think I have one of them in the next room. Have they done anything yet to the Baron?”

It was Burke’s turn now to look from one to the other of us in unfeigned surprise that we should already know something of his secret.

“The Baron?” he repeated, lowering his voice. “What Baron?”

It was evident that Burke knew nothing, at least of this new plot which Miss Lowe had indicated. Kennedy beckoned him over to the window furthest from the door to his own room.

“What have you discovered?” he asked, forestalling Burke in the questioning. “What has happened?”

“You haven’t heard, then?” replied Burke.

Kennedy nodded negatively.

“Fortescue, the American inventor of fortescite, the new explosive, died very strangely this morning.”

“Yes,” encouraged Kennedy, as Burke came to a full stop to observe the effect of the information.

“Most incomprehensible, too,” he pursued. “No cause, apparently. But it might have been overlooked, perhaps, except for one thing. It wasn’t known generally, but Fortescue had just perfected a successful electro-magnetic gun—powderless, smokeless, flashless, noiseless and of tremendous power. To-morrow he was to have signed the contract to sell it to England. This morning he is found dead and the final plans of the gun are gone!”

Kennedy and Burke were standing mutely looking at each other.

“Who is in the next room?” whispered Burke hoarsely, recollecting Kennedy’s caution of silence.

Kennedy did not reply immediately. He was evidently much excited by Burke’s news of the wonderful electro-magnetic gun.

“Burke,” he exclaimed suddenly, “let’s join forces. I think we are both on the trail of a world-wide conspiracy—a sort of murder syndicate to wipe out war!”

Burke’s only reply was a low whistle that involuntarily escaped him as he reached over and grasped Craig’s hand, which to him represented the sealing of the compact.

As for me, I could not restrain a mental shudder at the power that their first murder had evidently placed in the hands of the anarchists, if they indeed had the electro-magnetic gun which inventors had been seeking for generations. What might they not do with it—perhaps even use it themselves and turn the latest invention against society itself!

Hastily Craig gave a whispered account of our strange visit from Miss Lowe, while Burke listened, open-mouthed.

He had scarcely finished when he reached for the telephone and asked for long distance.

“Is this the German embassy in Washington?” asked Craig a few moments later when he got his number. “This is Craig Kennedy, in New York. The United States Secret Service will vouch for me—mention to them Mr. Burke of their New York office who is here with me now. I understand that Baron Kreiger is leaving for New York to meet some bankers this afternoon. He must not do so. He is in the gravest danger if he—What? He left last night at midnight and is already here?”

Kennedy turned to us blankly.

The door to his room opened suddenly.

There stood Miss Lowe, gazing wild-eyed at us. Evidently her supernervous condition had heightened the keenness of her senses. She had heard what we were saying. I tried to read her face. It was not fear that I saw there. It was rage; it was jealousy.

“The traitress—it is Marie!” she shrieked.

For a moment, obtusely, I did not understand.

“She has made a secret appointment with him,” she cried.

At last I saw the truth. Paula Lowe had fallen in love with the man she had sworn to kill!

CHAPTER II
THE ELECTRO-MAGNETIC GUN

“What shall we do?” demanded Burke, instantly taking in the dangerous situation that the Baron’s sudden change of plans had opened up.

“Call O’Connor,” I suggested, thinking of the police bureau of missing persons, and reaching for the telephone.

“No, no!” almost shouted Craig, seizing my arm. “The police will inevitably spoil it all. No, we must play a lone hand in this if we are to work it out. How was Fortescue discovered, Burke?”

“Sitting in a chair in his laboratory. He must have been there all night. There wasn’t a mark on him, not a sign of violence, yet his face was terribly drawn as though he were gasping for breath or his heart had suddenly failed him. So far, I believe, the coroner has no clue and isn’t advertising the case.”

“Take me there, then,” decided Craig quickly. “Walter, I must trust Miss Lowe to you on the journey. We must all go. That must be our starting point, if we are to run this thing down.”

I caught his significant look to me and interpreted it to mean that he wanted me to watch Miss Lowe especially. I gathered that taking her was in the nature of a third degree and as a result he expected to derive some information from her. Her face was pale and drawn as we four piled into a taxicab for a quick run downtown to the laboratory of Fortescue from which Burke had come directly to us with his story.

“What do you know of these anarchists?” asked Kennedy of Burke as we sped along. “Why do you suspect them?”

It was evident that he was discussing the case so that Paula could overhear, for a purpose.

“Why, we received a tip from abroad—I won’t say where,” replied Burke guardedly, taking his cue. “They call themselves the ‘Group,’ I believe, which is a common enough term among anarchists. It seems they are composed of terrorists of all nations.”

“The leader?” inquired Kennedy, leading him on.

“There is one, I believe, a little florid, stout German. I think he is a paranoiac who believes there has fallen on himself a divine mission to end all warfare. Quite likely he is one of those who have fled to America to avoid military service. Perhaps, why certainly, you must know him—Annenberg, an instructor in economics now at the University?”

Craig nodded and raised his eyebrows in mild surprise. We had indeed heard of Annenberg and some of his radical theories which had sometimes quite alarmed the conservative faculty. I felt that this was getting pretty close home to us now.

“How about Mrs. Annenberg?” Craig asked, recalling the clever young wife of the middle-aged professor.

At the mere mention of the name, I felt a sort of start in Miss Lowe, who was seated next to me in the taxicab. She had quickly recovered herself, but not before I saw that Kennedy’s plan of breaking down the last barrier of her reserve was working.

“She is one of them, too,” Burke nodded. “I have had my men out shadowing them and their friends. They tell me that the Annenbergs hold salons—I suppose you would call them that—attended by numbers of men and women of high social and intellectual position who dabble in radicalism and all sorts of things.”

“Who are the other leaders?” asked Craig. “Have you any idea?”

“Some idea,” returned Burke. “There seems to be a Frenchman, a tall, wiry man of forty-five or fifty with a black mustache which once had a military twist. There are a couple of Englishmen. Then there are five or six Americans who seem to be active. One, I believe, is a young woman.”

Kennedy checked him with a covert glance, but did not betray by a movement of a muscle to Miss Lowe that either Burke or himself suspected her of being the young woman in question.

“There are three Russians,” continued Burke, “all of whom have escaped from Siberia. Then there is at least one Austrian, a Spaniard from the Ferrer school, and Tomasso and Enrico, two Italians, rather heavily built, swarthy, bearded. They look the part. Of course there are others. But these in the main, I think, compose what might be called ‘the inner circle’ of the ‘Group.’”

It was indeed an alarming, terrifying revelation, as we began to realize that Miss Lowe had undoubtedly been telling the truth. Not alone was there this American group, evidently, but all over Europe the lines of the conspiracy had apparently spread. It was not a casual gathering of ordinary malcontents. It went deeper than that. It included many who in their disgust at war secretly were not unwilling to wink at violence to end the curse. I could not but reflect on the dangerous ground on which most of them were treading, shaking the basis of all civilization in order to cut out one modern excrescence.

The big fact to us, just at present, was that this group had made America its headquarters, that plans had been studiously matured and even reduced to writing, if Paula were to be believed. Everything had been carefully staged for a great simultaneous blow or series of blows that would rouse the whole world.

As I watched I could not escape observing that Miss Lowe followed Burke furtively now, as though he had some uncanny power.

Fortescue’s laboratory was in an old building on a side street several blocks from the main thoroughfares of Manhattan. He had evidently chosen it, partly because of its very inaccessibility in order to secure the quiet necessary for his work.

“If he had any visitors last night,” commented Kennedy when our cab at last pulled up before the place, “they might have come and gone unnoticed.”

We entered. Nothing had been disturbed in the laboratory by the coroner and Kennedy was able to gain a complete idea of the case rapidly, almost as well as if we had been called in immediately.

Fortescue’s body, it seemed, had been discovered sprawled out in a big armchair, as Burke had said, by one of his assistants only a few hours before when he had come to the laboratory in the morning to open it. Evidently he had been there undisturbed all night, keeping a gruesome vigil over his looted treasure house.

As we gleaned the meager facts, it became more evident that whoever had perpetrated the crime must have had the diabolical cunning to do it in some ordinary way that aroused no suspicion on the part of the victim, for there was no sign of any violence anywhere.

As we entered the laboratory, I noted an involuntary shudder on the part of Paula Lowe, but, as far as I knew, it was no more than might have been felt by anyone under the circumstances.

Fortescue’s body had been removed from the chair in which it had been found and lay on a couch at the other end of the room, covered merely by a sheet. Otherwise, everything, even the armchair, was undisturbed.

Kennedy pulled back a corner of the sheet, disclosing the face, contorted and of a peculiar, purplish hue from the congested blood vessels. He bent over and I did so, too. There was an unmistakable odor of tobacco on him. A moment Kennedy studied the face before us, then slowly replaced the sheet.

Miss Lowe had paused just inside the door and seemed resolutely bound not to look at anything. Kennedy meanwhile had begun a most minute search of the table and floor of the laboratory near the spot where the armchair had been sitting.

In my effort to glean what I could from her actions and expressions I did not notice that Craig had dropped to his knees and was peering into the shadow under the laboratory table. When at last he rose and straightened himself up, however, I saw that he was holding in the palm of his hand a half-smoked, gold-tipped cigarette, which had evidently fallen on the floor beneath the table where it had burned itself out, leaving a blackened mark on the wood.

An instant afterward he picked out from the pile of articles found in Fortescue’s pockets and lying on another table a silver cigarette case. He snapped it open. Fortescue’s cigarettes, of which there were perhaps a half dozen in the case, were cork-tipped.

Some one had evidently visited the inventor the night before, had apparently offered him a cigarette, for there were any number of the cork-tipped stubs lying about. Who was it? I caught Paula looking with fascinated gaze at the gold-tipped stub, as Kennedy carefully folded it up in a piece of paper and deposited it in his pocket. Did she know something about the case, I wondered?

Without a word, Kennedy seemed to take in the scant furniture of the laboratory at a glance and a quick step or two brought him before a steel filing cabinet. One drawer, which had not been closed as tightly as the rest, projected a bit. On its face was a little typewritten card bearing the inscription: “E-M GUN.”

He pulled the drawer open and glanced over the data in it.

“Just what is an electro-magnetic gun?” I asked, interpreting the initials on the drawer.

“Well,” he explained as he turned over the notes and sketches, “the primary principle involved in the construction of such a gun consists in impelling the projectile by the magnetic action of a solenoid, the sectional coils or helices of which are supplied with current through devices actuated by the projectile itself. In other words, the sections of helices of the solenoid produce an accelerated motion of the projectile by acting successively on it, after a principle involved in the construction of electro-magnetic rock drills and dispatch tubes.

“All projectiles used in this gun of Fortescue’s evidently must have magnetic properties and projectiles of iron or containing large portions of iron are necessary. You see, many coils are wound around the barrel of the gun. As the projectile starts it does so under the attraction of those coils ahead which the current makes temporary magnets. It automatically cuts off the current from those coils that it passes, allowing those further on only to attract it, and preventing those behind from pulling it back.”

He paused to study the scraps of plans. “Fortescue had evidently also worked out a way of changing the poles of the coils as the projectile passed, causing them then to repel the projectile, which must have added to its velocity. He seems to have overcome the practical difficulty that in order to obtain service velocities with service projectiles an enormous number of windings and a tremendously long barrel are necessary as well as an abnormally heavy current beyond the safe carrying capacity of the solenoid which would raise the temperature to a point that would destroy the coils.”

He continued turning over the prints and notes in the drawer. When he finished, he looked up at us with an expression that indicated that he had merely satisfied himself of something he had already suspected.

“You were right, Burke,” he said. “The final plans are gone.”

Burke, who, in the meantime, had been telephoning about the city in a vain effort to locate Baron Kreiger, both at such banking offices in Wall Street as he might be likely to visit and at some of the hotels most frequented by foreigners, merely nodded. He was evidently at a loss completely how to proceed.

In fact, there seemed to be innumerable problems—to warn Baron Kreiger, to get the list of the assassinations, to guard Miss Lowe against falling into the hands of her anarchist friends again, to find the murderer of Fortescue, to prevent the use of the electro-magnetic gun, and, if possible, to seize the anarchists before they had a chance to carry further their plans.

“There is nothing more that we can do here,” remarked Craig briskly, betraying no sign of hesitation. “I think the best thing we can do is to go to my own laboratory. There at least there is something I must investigate sooner or later.”

No one offering either a suggestion or an objection, we four again entered our cab. It was quite noticeable now that the visit had shaken Paula Lowe, but Kennedy still studiously refrained from questioning her, trusting that what she had seen and heard, especially Burke’s report as to Baron Kreiger, would have its effect.

Like everyone visiting Craig’s laboratory for the first time, Miss Lowe seemed to feel the spell of the innumerable strange and uncanny instruments which he had gathered about him in his scientific warfare against crime. I could see that she was becoming more and more nervous, perhaps fearing even that in some incomprehensible way he might read her own thoughts. Yet one thing I did not detect. She showed no disposition to turn back on the course on which she had entered by coming to us in the first place.

Kennedy was quickly and deftly testing the stub of the little thin, gold-tipped cigarette.

“Excessive smoking,” he remarked casually, “causes neuroses of the heart and tobacco has a specific affinity for the coronary arteries as well as a tremendous effect on the vagus nerve. But I don’t think this was any ordinary smoke.”

He had finished his tests and a quiet smile of satisfaction flitted momentarily over his face. We had been watching him anxiously, wondering what he had found.

As he looked up he remarked to us, with his eyes fixed on Miss Lowe, “That was a ladies’ cigarette. Did you notice the size? There has been a woman in this case—presumably.”

The girl, suddenly transformed by the rapid-fire succession of discoveries, stood before us like a specter.

“The ‘Group,’ as anarchists call it,” pursued Craig, “is the loosest sort of organization conceivable, I believe, with no set membership, no officers, no laws—just a place of meeting with no fixity, where the comrades get together. Could you get us into the inner circle, Miss Lowe?”

Her only answer was a little suppressed scream. Kennedy had asked the question merely for its effect, for it was only too evident that there was no time, even if she could have managed it, for us to play the “stool pigeon.”

Kennedy, who had been clearing up the materials he had used in the analysis of the cigarette, wheeled about suddenly. “Where is the headquarters of the inner circle?” he shot out.

Miss Lowe hesitated. That had evidently been one of the things she had determined not to divulge.

“Tell me,” insisted Kennedy. “You must!”

If it had been Burke’s bulldozing she would never have yielded. But as she looked into Kennedy’s eyes she read there that he had long since fathomed the secret of her wildly beating heart, that if she would accomplish the purpose of saving the Baron she must stop at nothing.

“At—Maplehurst,” she answered in a low tone, dropping her eyes from his penetrating gaze, “Professor Annenberg’s home—out on Long Island.”

“We must act swiftly if we are to succeed,” considered Kennedy, his tone betraying rather sympathy with than triumph over the wretched girl who had at last cast everything in the balance to outweigh the terrible situation into which she had been drawn. “To send Miss Lowe for that fatal list of assassinations is to send her either back into the power of this murderous group and let them know that she has told us, or perhaps to involve her again in the completion of their plans.”

She sank back into a chair in complete nervous and physical collapse, covering her face with her hands at the realization that in her new-found passion to save the Baron she had bared her sensitive soul for the dissection of three men whom she had never seen before.

“We must have that list,” pursued Kennedy decisively. “We must visit Annenberg’s headquarters.”

“And I?” she asked, trembling now with genuine fear at the thought that he might ask her to accompany us as he had on our visit to Fortescue’s laboratory that morning.

“Miss Lowe,” said Kennedy, bending over her, “you have gone too far now ever to turn back. You are not equal to the trip. Would you like to remain here? No one will suspect. Here at least you will be safe until we return.”

Her answer was a mute expression of thanks and confidence.

CHAPTER III
THE MURDER SYNDICATE

Quickly now Craig completed his arrangements for the visit to the headquarters of the real anarchist leader. Burke telephoned for a high-powered car, while Miss Lowe told frankly of the habits of Annenberg and the chances of finding his place unguarded, which were good in the daytime. Kennedy’s only equipment for the excursion consisted in a small package which he took from a cabinet at the end of the room, and, with a parting reassurance to Paula Lowe, we were soon speeding over the bridge to the borough across the river.

We realized that it might prove a desperate undertaking, but the crisis was such that it called for any risk.

Our quest took us to a rather dilapidated old house on the outskirts of the little Long Island town. The house stood alone, not far from the tracks of a trolley that ran at infrequent intervals. Even a hasty reconnoitering showed that to stop our motor at even a reasonable distance from it was in itself to arouse suspicion.

Although the house seemed deserted, Craig took no chances, but directed the car to turn at the next crossroad and then run back along a road back of and parallel to that on which Annenberg’s was situated. It was perhaps a quarter of a mile away, across an open field, that we stopped and ran the car up along the side of the road in some bushes. Annenberg’s was plainly visible and it was not at all likely that anyone there would suspect trouble from that quarter.

A hasty conference with Burke followed, in which Kennedy unwrapped his small package, leaving part of its contents with him, and adding careful instructions.

Then Kennedy and I retraced our steps down the road, across by the crossroad, and at last back to the mysterious house.

To all appearance there had been no need of such excessive caution. Not a sound or motion greeted us as we entered the gate and made our way around to the rear of the house. The very isolation of the house was now our protection, for we had no inquisitive neighbors to watch us for the instant when Kennedy, with the dexterity of a yeggman, inserted his knife between the sashes of the kitchen window and turned the catch which admitted us.

We made our way on cautious tiptoe through a dining room to a living room, and, finding nothing, proceeded upstairs. There was not a soul, apparently, in the house, nor in fact anything to indicate that it was different from most small suburban homes, until at last we mounted to the attic.

It was finished off in one large room across the back of the house and two in front. As we opened the door to the larger room, we could only gaze about in surprise. This was the rendezvous, the arsenal, literary, explosive and toxicological of the “Group.” Ranged on a table were all the materials for bomb-making, while in a cabinet I fancied there were poisons enough to decimate a city.

On the walls were pictures, mostly newspaper prints, of the assassins of McKinley, of King Humbert, of the King of Greece, of King Carlos and others, interspersed with portraits of anarchist and anti-militarist leaders of all lands.

Kennedy sniffed. Over all I, too, could catch the faint odor of stale tobacco. No time was to be lost, however, and while Craig set to work rapidly going through the contents of a desk in the corner, I glanced over the contents of a drawer of a heavy mission table.

“Here’s some of Annenberg’s literature,” I remarked, coming across a small pile of manuscript, entitled “The Human Slaughter House.”

“Read it,” panted Kennedy, seeing that I had about completed my part of the job. “It may give a clue.”

Hastily I scanned the mad, frantic indictment of war, while Craig continued in his search:

“I see wild beasts all around me, distorted unnaturally, in a life and death struggle, with bloodshot eyes, with foaming, gnashing mouths. They attack and kill one another and try to mangle each other. I leap to my feet. I race out into the night and tread on quaking flesh, step on hard heads, and stumble over weapons and helmets. Something is clutching at my feet like hands, so that I race away like a hunted deer with the hounds at his heels—and ever over more bodies—breathless… out of one field into another. Horror is crooning over my head. Horror is crooning beneath my feet. And nothing but dying, mangled flesh!

“Of a sudden I see nothing but blood before me. The heavens have opened and the red blood pours in through the windows. Blood wells up on an altar. The walls run blood from the ceiling to the floor and… a giant of blood stands before me. His beard and his hair drip blood. He seats himself on the altar and laughs from thick lips. The black executioner raises his sword and whirls it above my head. Another moment and my head will roll down on the floor. Another moment and the red jet will spurt from my neck.

“Murderers! Murderers! None other than murderers!”

I paused in the reading. “There’s nothing here,” I remarked, glancing over the curious document for a clue, but finding none.

“Well,” remarked Craig contemplatively, “one can at least easily understand how sensitive and imaginative people who have fallen under the influence of one who writes in that way can feel justified in killing those responsible for bringing such horrors on the human race. Hello—what’s this?”

He had discovered a false back of one of the drawers in the desk and had jimmied it open. On the top of innumerable papers lay a large linen envelope. On its face it bore in typewriting, just like the card on the drawer at Fortescue’s, “E-M GUN.”

“It is the original envelope that contained the final plans of the electro-magnetic gun,” he explained, opening it.

The envelope was empty. We looked at each other a moment in silence. What had been done with the plans?

Suddenly a bell rang, startling me beyond measure. It was, however, only the telephone, of which an extension reached up into the attic-arsenal. Some one, who did not know that we were there, was evidently calling up.

Kennedy quickly unhooked the receiver with a hasty motion to me to be silent.

“Hello,” I heard him answer. “Yes, this is it.”

He had disguised his voice. I waited anxiously and watched his face to gather what response he received.

“The deuce!” he exclaimed, with his hand over the transmitter so that his voice would not be heard at the other end of the line.

“What’s the matter?” I asked eagerly.

“It was Mrs. Annenberg—I am sure. But she was too keen for me. She caught on. There must be some password or form of expression that they use, which we don’t know, for she hung up the receiver almost as soon as she heard me.”

Kennedy waited a minute or so. Then he whistled into the transmitter. It was done apparently to see whether there was anyone listening. But there was no answer.

“Operator, operator!” he called insistently, moving the hook up and down. “Yes, operator. Can you tell me what number that was which just called?”

He waited impatiently.

“Bleecker—7l80,” he repeated after the girl. “Thank you. Information, please.”

Again we waited, as Craig tried to trace the call up.

“What is the street address of Bleecker, 7180?” he asked. “Five hundred and one East Fifth—a tenement. Thank you.”

“A tenement?” I repeated blankly.

“Yes,” he cried, now for the first time excited. “Don’t you begin to see the scheme? I’ll wager that Baron Kreiger has been lured to New York to purchase the electro-magnetic gun which they have stolen from Fortescue and the British. That is the bait that is held out to him by the woman. Call up Miss Lowe at the laboratory and see if she knows the place.”

I gave central the number, while he fell to at the little secret drawer of the desk again. The grinding of the wheels of a passing trolley interfered somewhat with giving the number and I had to wait a moment.

“Ah—Walter—here’s the list!” almost shouted Kennedy, as he broke open a black-japanned dispatch box in the desk.

I bent over it, as far as the slack of the telephone wire of the receiver at my ear would permit. Annenberg had worked with amazing care and neatness on the list, even going so far as to draw at the top, in black, a death’s head. The rest of it was elaborately prepared in flaming red ink.

Craig gasped to observe the list of world-famous men marked for destruction in London, Paris, Berlin, Rome, Vienna, St. Petersburg, and even in New York and Washington.

“What is the date set?” I asked, still with my ear glued to the receiver.

“To-night and to-morrow,” he replied, stuffing the fateful sheet into his pocket.

Rummaging about in the drawer of the table, I had come to a package of gold-tipped cigarettes which had interested me and I had left them out. Kennedy was now looking at them curiously.

“What is to be the method, do you suppose?” I asked.

“By a poison that is among the most powerful, approaching even cyanogen,” he replied confidently, tapping the cigarettes. “Do you smell the odor in this room? What is it like?”

“Stale tobacco,” I replied.

“Exactly—nicotine. Two or three drops on the mouth-end of a cigar or cigarette. The intended victim thinks it is only natural. But it is the purest form of the deadly alkaloid—fatal in a few minutes, too.”

He examined the thin little cigarettes more carefully. “Nicotine,” he went on, “was about the first alkaloid that was recovered from the body by chemical analysis in a homicide case. That is the penetrating, persistent odor you smelled at Fortescue’s and also here. It’s a very good poison—if you are not particular about being discovered. A pound of ordinary smoking tobacco contains from a half to an ounce of it. It is almost entirely consumed by combustion; otherwise a pipeful would be fatal. Of course they may have thought that investigators would believe that their victims were inveterate smokers. But even the worst tobacco fiend wouldn’t show traces of the weed to such an extent.”

Miss Lowe answered at last and Kennedy took the telephone.

“What is at five hundred and one East Fifth?” he asked.

“A headquarters of the Group in the city,” she answered. “Why?”

“Well, I believe that the plans of that gun are there and that the Baron—”

“You damned spies!” came a voice from behind us.

Kennedy dropped the receiver, turning quickly, his automatic gleaming in his hand.

There was just a glimpse of a man with glittering bright blue eyes that had an almost fiendish, baleful glare. An instant later the door which had so unexpectedly opened banged shut, we heard a key turn in the lock—and the man dropped to the floor before even Kennedy’s automatic could test its ability to penetrate wood on a chance at hitting something the other side of it.

We were prisoners!

My mind worked automatically. At this very moment, perhaps, Baron Kreiger might be negotiating for the electro-magnetic gun. We had found out where he was, in all probability, but we were powerless to help him. I thought of Miss Lowe, and picked up the receiver which Kennedy had dropped.

She did not answer. The wire had been cut. We were isolated!

Kennedy had jumped to the window. I followed to restrain him, fearing that he had some mad scheme for climbing out. Instead, quickly he placed a peculiar arrangement, from the little package he had brought, holding it to his eye as if sighting it, his right hand grasping a handle as one holds a stereoscope. A moment later, as I examined it more closely, I saw that instead of looking at anything he had before him a small parabolic mirror turned away from him.

His finger pressed alternately on a button on the handle and I could see that there flashed in the little mirror a minute incandescent lamp which seemed to have a special filament arrangement.

The glaring sun was streaming in at the window and I wondered what could possibly be accomplished by the little light in competition with the sun itself.

“Signaling by electric light in the daytime may sound to you ridiculous,” explained Craig, still industriously flashing the light, “but this arrangement with Professor Donath’s signal mirror makes it possible, all right.

“I hadn’t expected this, but I thought I might want to communicate with Burke quickly. You see, I sight the lamp and then press the button which causes the light in the mirror to flash. It seems a paradox that a light like this can be seen from a distance of even five miles and yet be invisible to one for whom it was not intended, but it is so. I use the ordinary Morse code—two seconds for a dot, six for a dash with a four-second interval.”

“What message did you send?” I asked.

“I told him that Baron Kreiger was at five hundred and one East Fifth, probably; to get the secret service office in New York by wire and have them raid the place, then to come and rescue us. That was Annenberg. He must have come up by that trolley we heard passing just before.”

The minutes seemed ages as we waited for Burke to start the machinery of the raid and then come for us.

“No—you can’t have a cigarette—and if I had a pair of bracelets with me, I’d search you myself,” we heard a welcome voice growl outside the door a few minutes later. “Look in that other pocket, Tom.”

The lock grated back and there stood Burke holding in a grip of steel the undersized Annenberg, while the chauffeur who had driven our car swung open the door.

“I’d have been up sooner,” apologized Burke, giving the anarchist an extra twist just to let him know that he was at last in the hands of the law, “only I figured that this fellow couldn’t have got far away in this God-forsaken Ducktown and I might as well pick him up while I had a chance. That’s a great little instrument of yours, Kennedy. I got you, fine.”

Annenberg, seeing we were now four to one, concluded that discretion was the better part of valor and ceased to struggle, though now and then I could see he glanced at Kennedy out of the corner of his eye. To every question he maintained a stolid silence.

A few minutes later, with the arch anarchist safely pinioned between us, we were speeding back toward New York, laying plans for Burke to dispatch warnings abroad to those whose names appeared on the fatal list, and at the same time to round up as many of the conspirators as possible in America.

As for Kennedy, his main interest now lay in Baron Kreiger and Paula. While she had been driven frantic by the outcome of the terrible pact into which she had been drawn, some one, undoubtedly, had been trying to sell Baron Kreiger the gun that had been stolen from the American inventor. Once they had his money and he had received the plans of the gun, a fatal cigarette would be smoked. Could we prevent it?

On we tore back to the city, across the bridge and down through the canyons of East Side streets.

At last we pulled up before the tenement at five hundred and one. As we did so, one of Burke’s men jumped out of the doorway.

“Are we in time?” shouted Burke.

“It’s an awful mix-up,” returned the man. “I can’t make anything out of it, so I ordered ’em all held here till you came.”

We pushed past without a word of criticism of his wonderful acumen.

On the top floor we came upon a young man, bending over the form of a girl who had fainted. On the floor of the middle of the room was a mass of charred papers which had evidently burned a hole in the carpet before they had been stamped out. Near by was an unlighted cigarette, crushed flat on the floor.

“How is she?” asked Kennedy anxiously of the young man, as he dropped down on the other side of the girl.

It was Paula. She had fainted, but was just now coming out of the borderland of unconsciousness.

“Was I in time? Had he smoked it?” she moaned weakly, as there swam before her eyes, evidently, a hazy vision of our faces.

Kennedy turned to the young man.

“Baron Kreiger, I presume?” he inquired.

The young man nodded.

“Burke of the Secret Service,” introduced Craig, indicating our friend. “My name is Kennedy. Tell what happened.”

“I had just concluded a transaction,” returned Kreiger in good but carefully guarded English. “Suddenly the door burst open. She seized these papers and dashed a cigarette out of my hands. The next instant she had touched a match to them and had fallen in a faint almost in the blaze. Strangest experience I ever had in my life. Then all these other fellows came bursting in—said they were Secret Service men, too.”

Kennedy had no time to reply, for a cry from Annenberg directed our attention to the next room where on a couch lay a figure all huddled up.

As we looked we saw it was a woman, her head sweating profusely, and her hands cold and clammy. There was a strange twitching of the muscles of the face, the pupils of her eyes were widely dilated, her pulse weak and irregular. Evidently her circulation had failed so that it responded only feebly to stimulants, for her respiration was slow and labored, with loud inspiratory gasps.

Annenberg had burst with superhuman strength from Burke’s grasp and was kneeling by the side of his wife’s deathbed.

“It—was all Paula’s fault—” gasped the woman. “I—knew I had better—carry it through—like the Fortescue visit—alone.”

I felt a sense of reassurance at the words. At least my suspicions had been unfounded. Paula was innocent of the murder of Fortescue.

“Severe, acute nicotine poisoning,” remarked Kennedy, as he rejoined us a moment later. “There is nothing we can do—now.”

Paula moved at the words, as though they had awakened a new energy in her. With a supreme effort she raised herself.

“Then I—I failed?” she cried, catching sight of Kennedy.

“No, Miss Lowe,” he answered gently. “You won. The plans of the terrible gun are destroyed. The Baron is safe. Mrs. Annenberg has herself smoked one of the fatal cigarettes intended for him.”

Kreiger looked at us, uncomprehending. Kennedy picked up the crushed, unlighted cigarette and laid it in the palm of his hand beside another, half smoked, which he had found beside Mrs. Annenberg.

“They are deadly,” he said simply to Kreiger. “A few drops of pure nicotine hidden by that pretty gilt tip would have accomplished all that the bitterest anarchist could desire.”

All at once Kreiger seemed to realize what he had escaped so narrowly. He turned toward Paula. The revulsion of her feelings at seeing him safe was too much for her shattered nerves.

With a faint little cry, she tottered.

Before any of us could reach her, he had caught her in his arms and imprinted a warm kiss on the insensible lips.

“Some water—quick!” he cried, still holding her close.

CHAPTER IV
THE AIR PIRATE

Rounding up the “Group” took several days, and it proved to be a great story for the Star. I was pretty fagged when it was all over, but there was a great deal of satisfaction in knowing that we had frustrated one of the most daring anarchist plots of recent years.

“Can you arrange to spend the week-end with me at Stuyvesant Verplanck’s at Bluffwood?” asked Kennedy over the telephone, the afternoon that I had completed my work on the newspaper of undoing what Annenberg and the rest had attempted.

“How long since society took you up?” I asked airily, adding, “Is it a large house party you are getting up?”

“You have heard of the so-called ‘phantom bandit’ of Bluffwood, haven’t you?” he returned rather brusquely, as though there was no time now for bantering.

I confess that in the excitement of the anarchists I had forgotten it, but now I recalled that for several days I had been reading little paragraphs about robberies on the big estates on the Long Island shore of the Sound. One of the local correspondents had called the robber a “phantom bandit,” but I had thought it nothing more than an attempt to make good copy out of a rather ordinary occurrence.

“Well,” he hurried on, “that’s the reason why I have been ‘taken up by society,’ as you so elegantly phrase it. From the secret hiding-places of the boudoirs and safes of fashionable women at Bluffwood, thousands of dollars’ worth of jewels and other trinkets have mysteriously vanished. Of course you’ll come along. Why, it will be just the story to tone up that alleged page of society news you hand out in the Sunday Star. There—we’re quits now. Seriously, though, Walter, it really seems to be a very baffling case, or rather series of cases. The whole colony out there is terrorized. They don’t know who the robber is, or how he operates, or who will be the next victim, but his skill and success seem almost uncanny. Mr. Verplanck has put one of his cars at my disposal and I’m up here at the laboratory gathering some apparatus that may be useful. I’ll pick you up anywhere between this and the Bridge—how about Columbus Circle in half an hour?”

“Good,” I agreed, deciding quickly from his tone and manner of assurance that it would be a case I could not afford to miss.

The Stuyvesant Verplancks, I knew, were among the leaders of the rather recherché society at Bluffwood, and the pace at which Bluffwood moved and had its being was such as to guarantee a good story in one way or another.

“Why,” remarked Kennedy, as we sped out over the picturesque roads of the north shore of Long Island, “this fellow, or fellows, seems to have taken the measure of all the wealthy members of the exclusive organizations out there—the Westport Yacht Club, the Bluffwood Country Club, the North Shore Hunt, and all of them. It’s a positive scandal, the ease with which he seems to come and go without detection, striking now here, now there, often at places that it seems physically impossible to get at, and yet always with the same diabolical skill and success. One night he will take some baubles worth thousands, the next pass them by for something apparently of no value at all, a piece of bric-à-brac, a bundle of letters, anything.”

“Seems purposeless, insane, doesn’t it?” I put in.

“Not when he always takes something—often more valuable than money,” returned Craig.

He leaned back in the car and surveyed the glimpses of bay and countryside as we were whisked by the breaks in the trees.

“Walter,” he remarked meditatively, “have you ever considered the possibilities of blackmail if the right sort of evidence were obtained under this new ‘white-slavery act’? Scandals that some of the fast set may be inclined to wink at, that at worst used to end in Reno, become felonies with federal prison sentences looming up in the background. Think it over.”

Stuyvesant Verplanck had telephoned rather hurriedly to Craig earlier in the day, retaining his services, but telling only in the briefest way of the extent of the depredations, and hinting that more than jewelry might be at stake.

It was a pleasant ride, but we finished it in silence. Verplanck was, as I recalled, a large masterful man, one of those who demanded and liked large things—such as the estate of several hundred acres which we at last entered.

It was on a neck of land with the restless waters of the Sound on one side and the calmer waters of the bay on the other. Westport Bay lay in a beautifully wooded, hilly country, and the house itself was on an elevation, with a huge sweep of terraced lawn before it down to the water’s edge. All around, for miles, were other large estates, a veritable colony of wealth.

As we pulled up under the broad stone porte-cochère, Verplanck, who had been expecting us, led the way into his library, a great room, literally crowded with curios and objects of art which he had collected on his travels. It was a superb mental workshop, overlooking the bay, with a stretch of several miles of sheltered water.

“You will recall,” began Verplanck, wasting no time over preliminaries, but plunging directly into the subject, “that the prominent robberies of late have been at seacoast resorts, especially on the shores of Long Island Sound, within, say, a hundred miles of New York. There has been a great deal of talk about dark and muffled automobiles that have conveyed mysterious parties swiftly and silently across country.

“My theory,” he went on self-assertively, “is that the attack has been made always along water routes. Under shadow of darkness, it is easy to slip into one of the sheltered coves or miniature fiords with which the north coast of the Island abounds, land a cut-throat crew primed with exact information of the treasure on some of these estates. Once the booty is secured, the criminal could put out again into the Sound without leaving a clue.”

He seemed to be considering his theory. “Perhaps the robberies last summer at Narragansett, Newport, and a dozen other New England places were perpetrated by the same cracksman. I believe,” he concluded, lowering his voice, “that there plies to-day on the wide waters of the Sound a slim, swift motor boat which wears the air of a pleasure craft, yet is as black a pirate as ever flew the Jolly Roger. She may at this moment be anchored off some exclusive yacht club, flying the respectable burgee of the club—who knows?”

He paused as if his deductions settled the case so far. He would have resumed in the same vein, if the door had not opened. A lady in a cobwebby gown entered the room. She was of middle age, but had retained her youth with a skill that her sisters of less leisure always envy. Evidently she had not expected to find anyone, yet nothing seemed to disconcert her.

“Mrs. Verplanck,” her husband introduced, “Professor Kennedy and his associate, Mr. Jameson—those detectives we have heard about. We were discussing the robberies.”

“Oh, yes,” she said, smiling, “my husband has been thinking of forming himself into a vigilance committee. The local authorities are all at sea.”

I thought there was a trace of something veiled in the remark and fancied, not only then but later, that there was an air of constraint between the couple.

“You have not been robbed yourself?” queried Craig tentatively.

“Indeed we have,” exclaimed Verplanck quickly. “The other night I was awakened by the noise of some one down here in this very library. I fired a shot, wild, and shouted, but before I could get down here the intruder had fled through a window, and half rolling down the terraces. Mrs. Verplanck was awakened by the rumpus and both of us heard a peculiar whirring noise.”

“Like an automobile muffled down,” she put in.

“No,” he asserted vigorously, “more like a powerful motor boat, one with the exhaust under water.”

“Well,” she shrugged, “at any rate, we saw no one.”

“Did the intruder get anything?”

“That’s the lucky part. He had just opened this safe apparently and begun to ransack it. This is my private safe. Mrs. Verplanck has another built into her own room upstairs where she keeps her jewels.”

“It is not a very modern safe, is it?” ventured Kennedy. “The fellow ripped off the outer casing with what they call a ‘can-opener.’”

“No. I keep it against fire rather than burglars. But he overlooked a box of valuable heirlooms, some silver with the Verplanck arms. I think I must have scared him off just in time. He seized a package in the safe, but it was only some business correspondence. I don’t relish having lost it, particularly. It related to a gentlemen’s agreement a number of us had in the recent cotton corner. I suppose the Government would like to have it. But—here’s the point. If it is so easy to get in and get away, no one in Bluffwood is safe.”

“Why, he robbed the Montgomery Carter place the other night,” remarked Mrs. Verplanck, “and almost got a lot of old Mrs. Carter’s jewels as well as stuff belonging to her son, Montgomery, Junior. That was the first robbery. Mr. Carter, that is Junior—Monty, everyone calls him—and his chauffeur almost captured the fellow, but he managed to escape in the woods.”

“In the woods?” repeated Craig.

Mrs. Verplanck nodded. “But they saved the loot he was about to take.”

“Oh, no one is safe any more,” reiterated Verplanck. “Carter seems to be the only one who has had a real chance at him, and he was able to get away neatly.”

“But he’s not the only one who got off without a loss,” she put in significantly. “The last visit—” Then she paused.

“Where was the last attempt?” asked Kennedy.

“At the house of Mrs. Hollingsworth—around the point on this side of the bay. You can’t see it from here.”

“I’d like to go there,” remarked Kennedy.

“Very well. Car or boat?”

“Boat, I think.”

“Suppose we go in my little runabout, the Streamline II? She’s as fast as any ordinary automobile.”

“Very good. Then we can get an idea of the harbor.”

“I’ll telephone first that we are coming,” said Verplanck.

“I think I’ll go, too,” considered Mrs. Verplanck, ringing for a heavy wrap.

“Just as you please,” said Verplanck.

The Streamline was a three-stepped boat which. Verplanck had built for racing, a beautiful craft, managed much like a racing automobile. As she started from the dock, the purring drone of her eight cylinders sent her feathering over the waves like a skipping stone. She sank back into the water, her bow leaping upward, a cloud of spray in her wake, like a waterspout.

Mrs. Hollingsworth was a wealthy divorcée, living rather quietly with her two children, of whom the courts had awarded her the care. She was a striking woman, one of those for whom the new styles of dress seem especially to have been designed. I gathered, however, that she was not on very good terms with the little Westport clique in which the Verplancks moved, or at least not with Mrs. Verplanck. The two women seemed to regard each other rather coldly, I thought, although Mr. Verplanck, man-like, seemed to scorn any distinctions and was more than cordial. I wondered why Mrs. Verplanck had come.

The Hollingsworth house was a beautiful little place down the bay from the Yacht Club, but not as far as Verplanck’s, or the Carter estate, which was opposite.

“Yes,” replied Mrs. Hollingsworth when the reason for our visit had been explained, “the attempt was a failure. I happened to be awake, rather late, or perhaps you would call it early. I thought I heard a noise as if some one was trying to break into the drawing-room through the window. I switched on all the lights. I have them arranged so for just that purpose of scaring off intruders. Then, as I looked out of my window on the second floor, I fancied I could see a dark figure slink into the shadow of the shrubbery at the side of the house. Then there was a whirr. It might have been an automobile, although it sounded differently from that—more like a motor boat. At any rate, there was no trace of a car that we could discover in the morning. The road had been oiled, too, and a car would have left marks. And yet some one was here. There were marks on the drawing-room window just where I heard the sounds.”

Who could it be? I asked myself as we left. I knew that the great army of chauffeurs was infested with thieves, thugs and gunmen. Then, too, there were maids, always useful as scouts for these corsairs who prey on the rich. Yet so adroitly had everything been done in these cases that not a clue seemed to have been left behind by which to trace the thief.

We returned to Verplanck’s in the Streamline in record time, dined, and then found McNeill, a local detective, waiting to add his quota of information. McNeill was of the square-toed, double-chinned, bull-necked variety, just the man to take along if there was any fighting. He had, however, very little to add to the solution of the mystery, apparently believing in the chauffeur-and-maid theory.

It was too late to do anything more that night, and we sat on the Verplanck porch, overlooking the beautiful harbor. It was a black, inky night, with no moon, one of those nights when the myriad lights on the boats were mere points in the darkness. As we looked out over the water, considering the case which as yet we had hardly started on, Kennedy seemed engrossed in the study in black.

“I thought I saw a moving light for an instant across the bay, above the boats, and as though it were in the darkness of the hills on the other side. Is there a road over there, above the Carter house?” he asked suddenly.

“There is a road part of the way on the crest of the hill,” replied Mrs. Verplanck. “You can see a car on it, now and then, through the trees, like a moving light.”

“Over there, I mean,” reiterated Kennedy, indicating the light as it flashed now faintly, then disappeared, to reappear further along, like a gigantic firefly in the night.

“N-no,” said Verplanck. “I don’t think the road runs down as far as that. It is further up the bay.”

“What is it then?” asked Kennedy, half to himself. “It seems to be traveling rapidly. Now it must be about opposite the Carter house. There—it has gone.”

We continued to watch for several minutes, but it did not reappear. Could it have been a light on the mast of a boat moving rapidly up the bay and perhaps nearer to us than we suspected? Nothing further happened, however, and we retired early, expecting to start with fresh minds on the case in the morning. Several watchmen whom Verplanck employed both on the shore and along the driveways were left guarding every possible entrance to the estate.

Yet the next morning as we met in the cheery east breakfast room, Verplanck’s gardener came in, hat in hand, with much suppressed excitement.

In his hand he held an orange which he had found in the shrubbery underneath the windows of the house. In it was stuck a long nail and to the nail was fastened a tag.

Kennedy read it quickly.

“If this had been a bomb, you and your detectives would never have known what struck you.

“AQUAERO.”

CHAPTER V
THE ULTRA-VIOLET RAY

“Good Gad, man!” exclaimed Verplanck, who had read it over Craig’s shoulder. “What do you make of that?”

Kennedy merely shook his head. Mrs. Verplanck was the calmest of all.

“The light,” I cried. “You remember the light? Could it have been a signal to some one on this side of the bay, a signal light in the woods?”

“Possibly,” commented Kennedy absently, adding, “Robbery with this fellow seems to be an art as carefully strategized as a promoter’s plan or a merchant’s trade campaign. I think I’ll run over this morning and see if there is any trace of anything on the Carter estate.”

Just then the telephone rang insistently. It was McNeill, much excited, though he had not heard of the orange incident. Verplanck answered the call.

“Have you heard the news?” asked McNeill. “They report this morning that that fellow must have turned up last night at Belle Aire.”

“Belle Aire? Why, man, that’s fifty miles away and on the other side of the island. He was here last night,” and Verplanck related briefly the find of the morning. “No boat could get around the island in that time and as for a car—those roads are almost impossible at night.”

“Can’t help it,” returned McNeill doggedly. “The Halstead estate out at Belle Aire was robbed last night. It’s spooky all right.”

“Tell McNeill I want to see him—will meet him in the village directly,” cut in Craig before Verplanck had finished.

We bolted a hasty breakfast and in one of Verplanck’s cars hurried to meet McNeill.

“What do you intend doing?” he asked helplessly, as Kennedy finished his recital of the queer doings of the night before.

“I’m going out now to look around the Carter place. Can you come along?”

“Surely,” agreed McNeill, climbing into the car. “You know him?”

“No.”

“Then I’ll introduce you. Queer chap, Carter. He’s a lawyer, although I don’t think he has much practice, except managing his mother’s estate.”

McNeill settled back in the luxurious car with an exclamation of satisfaction.

“What do you think of Verplanck?” he asked.

“He seems to me to be a very public-spirited man,” answered Kennedy discreetly.

That, however, was not what McNeill meant and he ignored it. And so for the next ten minutes we were entertained with a little retail scandal of Westport and Bluffwood, including a tale that seemed to have gained currency that Verplanck and Mrs. Hollingsworth were too friendly to please Mrs. Verplanck. I set the whole thing down to the hostility and jealousy of the towns people who misinterpret everything possible in the smart set, although I could not help recalling how quickly she had spoken when we had visited the Hollingsworth house in the Streamline the day before.

Montgomery Carter happened to be at home and, at least openly, interposed no objection to our going about the grounds.

“You see,” explained Kennedy, watching the effect of his words as if to note whether Carter himself had noticed anything unusual the night before, “we saw a light moving over here last night. To tell the truth, I half expected you would have a story to add to ours, of a second visit.”

Carter smiled. “No objection at all. I’m simply nonplussed at the nerve of this fellow, coming back again. I guess you’ve heard what a narrow squeak he had with me. You’re welcome to go anywhere, just so long as you don’t disturb my study down there in the boathouse. I use that because it overlooks the bay—just the place to study over knotty legal problems.”

Back of, or in front of the Carter house, according as you fancied it faced the bay or not, was the boathouse, built by Carter’s father, who had been a great yachtsman in his day and commodore of the club. His son had not gone in much for water sports and had converted the corner underneath a sort of observation tower into a sort of country law office.

“There has always seemed to me to be something strange about that boathouse since the old man died,” remarked McNeill in a half whisper as we left Carter. “He always keeps it locked and never lets anyone go in there, although they say he has it fitted beautifully with hundreds of volumes of law books, too.”

Kennedy had been climbing the hill back of the house and now paused to look about. Below was the Carter garage.

“By the way,” exclaimed McNeill, as if he had at last hit on a great discovery, “Carter has a new chauffeur, a fellow named Wickham. I just saw him driving down to the village. He’s a chap that it might pay us to watch—a newcomer, smart as a steel trap, they say, but not much of a talker.”

“Suppose you take that job—watch him,” encouraged Kennedy. “We can’t know too much about strangers here, McNeill.”

“That’s right,” agreed the detective. “I’ll follow him back to the village and get a line on him.”

“Don’t be easily discouraged,” added Kennedy, as McNeill started down the hill to the garage. “If he is a fox he’ll try to throw you off the trail. Hang on.”

“What was that for?” I asked as the detective disappeared. “Did you want to get rid of him?”

“Partly,” replied Craig, descending slowly, after a long survey of the surrounding country.

We had reached the garage, deserted now except for our own car.

“I’d like to investigate that tower,” remarked Kennedy with a keen look at me, “if it could be done without seeming to violate Mr. Carter’s hospitality.”

“Well,” I observed, my eye catching a ladder beside the garage, “there’s a ladder. We can do no more than try.”

He walked over to the automobile, took a little package out, slipped it into his pocket, and a few minutes later we had set the ladder up against the side of the boathouse farthest away from the house. It was the work of only a moment for Kennedy to scale it and prowl across the roof to the tower, while I stood guard at the foot.

“No one has been up there recently,” he panted breathlessly as he rejoined me. “There isn’t a sign.”

We took the ladder quietly back to the garage, then Kennedy led the way down the shore to a sort of little summerhouse cut off from the boathouse and garage by the trees, though over the top of a hedge one could still see the boathouse tower.

We sat down, and Craig filled his lungs with the good salt air, sweeping his eye about the blue and green panorama as though this were a holiday and not a mystery case.

“Walter,” he said at length, “I wish you’d take the car and go around to Verplanck’s. I don’t think you can see the tower through the trees, but I should like to be sure.”

I found that it could not be seen, though I tried all over the place and got myself disliked by the gardener and suspected by a watchman with a dog.

It could not have been from the tower of the boathouse that we had seen the light, and I hurried back to Craig to tell him so. But when I returned, I found that he was impatiently pacing the little rustic summerhouse, no longer interested in what he had sent me to find out.

“What has happened?” I asked eagerly.

“Just come out here and I’ll show you something,” he replied, leaving the summerhouse and approaching the boathouse from the other side of the hedge, on the beach, so that the house itself cut us off from observation from Carter’s.

“I fixed a lens on the top of that tower when I was up there,” he explained, pointing up at it. “It must be about fifty feet high. From there, you see, it throws a reflection down to this mirror. I did it because through a skylight in the tower I could read whatever was written by anyone sitting at Carter’s desk in the corner under it.”

“Read?” I repeated, mystified.

“Yes, by invisible light,” he continued. “This invisible light business, you know, is pretty well understood by this time. I was only repeating what was suggested once by Professor Wood of Johns Hopkins. Practically all sources of light, you understand, give out more or less ultraviolet light, which plays no part in vision whatever. The human eye is sensitive to but few of the light rays that reach it, and if our eyes were constituted just the least bit differently we should have an entirely different set of images.

“But by the use of various devices we can, as it were, translate these ultraviolet rays into terms of what the human eye can see. In order to do it, all the visible light rays which show us the thing as we see it—the tree green, the sky blue—must be cut off. So in taking an ultraviolet photograph a screen must be used which will be opaque to these visible rays and yet will let the ultraviolet rays through to form the image. That gave Professor Wood a lot of trouble. Glass won’t do, for glass cuts off the ultraviolet rays entirely. Quartz is a very good medium, but it does not cut off all the visible light. In fact there is only one thing that will do the work, and that is metallic silver.”

I could not fathom what he was driving at, but the fascination of Kennedy himself was quite sufficient.

“Silver,” he went on, “is all right if the objects can be illuminated by an electric spark or some other source rich in the rays. But it isn’t entirely satisfactory when sunlight is concerned, for various reasons that I need not bore you with. Professor Wood has worked out a process of depositing nickel on glass. That’s it up there,” he concluded, wheeling a lower reflector about until it caught the image of the afternoon sun thrown from the lens on the top of the tower.

“You see,” he resumed, “that upper lens is concave so that it enlarges tremendously. I can do some wonderful tricks with that.”

I had been lighting a cigarette and held a box of safety wind matches in my hand.

“Give me that matchbox,” he asked.

He placed it at the foot of the tower. Then he went off, I should say, without exaggeration, a hundred feet.

The lettering on the matchbox could be seen in the silvered mirror, enlarged to such a point that the letters were plainly visible!

“Think of the possibilities in that,” he added excitedly. “I saw them at once. You can read what some one is writing at a desk a hundred, perhaps two hundred feet away.”

“Yes,” I cried, more interested in the practical aspects of it than in the mechanics and optics. “What have you found?”

“Some one came into the boathouse while you were away,” he said. “He had a note. It read, ‘Those new detectives are watching everything. We must have the evidence. You must get those letters to-night, without fail.’”

“Letters—evidence,” I repeated. “Who wrote it? Who received it?”

“I couldn’t see over the hedge who had entered the boathouse, and by the time I got around here he was gone.”

“Was it Wickham—or intended for Wickham?” I asked.

Kennedy shrugged his shoulders.

“We’ll gain nothing by staying here,” he said. “There is just one possibility in the case, and I can guard against that only by returning to Verplanck’s and getting some of that stuff I brought up here with me. Let us go.”

Late in the afternoon though it was, after our return, Kennedy insisted on hurrying from Verplanck’s to the Yacht Club up the bay. It was a large building, extending out into the water on made land, from which ran a long, substantial dock. He had stopped long enough only to ask Verplanck to lend him the services of his best mechanician, a Frenchman named Armand.

On the end of the yacht club dock Kennedy and Armand set up a large affair which looked like a mortar. I watched curiously, dividing my attention between them and the splendid view of the harbor which the end of the dock commanded on all sides.

“What is this?” I asked finally. “Fireworks?”

“A rocket mortar of light weight,” explained Kennedy, then dropped into French as he explained to Armand the manipulation of the thing.

There was a searchlight near by on the dock.

“You can use that?” queried Kennedy.

“Oh, yes. Mr. Verplanck, he is vice-commodore of the club. Oh, yes, I can use that. Why, Monsieur?”

Kennedy had uncovered a round brass case. It did not seem to amount to much, as compared to some of the complicated apparatus he had used. In it was a four-sided prism of glass—I should have said, cut off the corner of a huge glass cube.

He handed it to us.

“Look in it,” he said.

It certainly was about the most curious piece of crystal gazing I had ever done. Turn the thing any way I pleased and I could see my face in it, just as in an ordinary mirror.

“What do you call it?” Armand asked, much interested.

“A triple mirror,” replied Kennedy, and again, half in English and half in French, neither of which I could follow, he explained the use of the mirror to the mechanician.

We were returning up the dock, leaving Armand with instructions to be at the club at dusk, when we met McNeill, tired and disgusted.

“What luck?” asked Kennedy.

“Nothing,” he returned. “I had a ‘short’ shadow and a ‘long’ shadow at Wickham’s heels all day. You know what I mean. Instead of one man, two—the second sleuthing in the other’s tracks. If he escaped Number One, Number Two would take it up, and I was ready to move up into Number Two’s place. They kept him in sight about all the time. Not a fact. But then, of course, we don’t know what he was doing before we took up tailing him. Say,” he added, “I have just got word from an agency with which I correspond in New York that it is reported that a yeggman named ‘Australia Mac,’ a very daring and clever chap, has been attempting to dispose of some of the goods which we know have been stolen through one of the worst ‘fences’ in New York.”

“Is that all?” asked Craig, with the mention of Australia Mac showing the first real interest yet in anything that McNeill had done since we met him the night before.

“All so far. I wired for more details immediately.”

“Do you know anything about this Australia Mac?”

“Not much. No one does. He’s a new man, it seems, to the police here.”

“Be here at eight o’clock, McNeill,” said Craig, as we left the club for Verplanck’s. “If you can find out more about this yeggman, so much the better.”

“Have you made any progress?” asked Verplanck as we entered the estate a few minutes later.

“Yes,” returned Craig, telling only enough to whet his interest. “There’s a clue, as I half expected, from New York, too. But we are so far away that we’ll have to stick to my original plan. You can trust Armand?”

“Absolutely.”

“Then we shall transfer our activity to the Yacht Club to-night,” was all that Kennedy vouchsafed.

CHAPTER VI
THE TRIPLE MIRROR

It was the regular Saturday night dance at the club, a brilliant spectacle, faces that radiated pleasure, gowns that for startling combinations of color would have shamed a Futurist, music that set the feet tapping irresistibly—a scene which I shall pass over because it really has no part in the story.

The fascination of the ballroom was utterly lost on Craig. “Think of all the houses only half guarded about here to-night,” he mused, as we joined Armand and McNeill on the end of the dock. I could not help noting that that was the only idea which the gay, variegated, sparkling tango throng conveyed to him.

In front of the club was strung out a long line of cars, and at the dock several speed boats of national and international reputation, among them the famous Streamline II, at our instant beck and call. In it Craig had already placed some rather bulky pieces of apparatus, as well as a brass case containing a second triple mirror like that which he had left with Armand.

With McNeill, I walked back along the pier, leaving Kennedy with Armand, until we came to the wide porch, where we joined the wallflowers and the rocking-chair fleet. Mrs. Verplanck, I observed, was a beautiful dancer. I picked her out in the throng immediately, dancing with Carter.

McNeill tugged at my sleeve. Without a word I saw what he meant me to see. Verplanck and Mrs. Hollingsworth were dancing together. Just then, across the porch I caught sight of Kennedy at one of the wide windows. He was trying to attract Verplanck’s attention, and as he did so I worked my way through the throng of chatting couples leaving the floor until I reached him. Verplanck, oblivious, finished the dance; then, seeming to recollect that he had something to attend to, caught sight of us, and ran off during the intermission from the gay crowd to which he resigned Mrs. Hollingsworth.

“What is it?” he asked.

“There’s that light down the bay,” whispered Kennedy.

Instantly Verplanck forgot about the dance.

“Where?” he asked.

“In the same place.”

I had not noticed, but Mrs. Verplanck, woman-like, had been able to watch several things at once. She had seen us and had joined us.

“Would you like to run down there in the Streamline?” he asked. “It will only take a few minutes.”

“Very much.”

“What is it—that light again?” she asked, as she joined us in walking down the dock.

“Yes,” answered her husband, pausing to look for a moment at the stuff Kennedy had left with Armand. Mrs. Verplanck leaned over the Streamline, turned as she saw me, and said: “I wish I could go with you. But evening dress is not the thing for a shivery night in a speed boat. I think I know as much about it as Mr. Verplanck. Are you going to leave Armand?”

“Yes,” replied Kennedy, taking his place beside Verplanck, who was seated at the steering wheel. “Walter and McNeill, if you two will sit back there, we’re ready. All right.”

Armand had cast us off and Mrs. Verplanck waved from the end of the float as the Streamline quickly shot out into the night, a buzzing, throbbing shape of mahogany and brass, with her exhausts sticking out like funnels and booming like a pipe organ. It took her only seconds to eat into the miles.

“A little more to port,” said Kennedy, as Verplanck swung her around.

Just then the steady droning of the engine seemed a bit less rhythmical. Verplanck throttled her down, but it had no effect. He shut her off. Something was wrong. As he crawled out into the space forward of us where the engine was, it seemed as if the Streamline had broken down suddenly and completely.

Here we were floundering around in the middle of the bay.

“Chuck-chuck-chuck,” came in quick staccato out of the night. It was Montgomery Carter, alone, on his way across the bay from the club, in his own boat.

“Hello—Carter,” called Verplanck.

“Hello, Verplanck. What’s the matter?”

“Don’t know. Engine trouble of some kind. Can you give us a line?”

“I’ve got to go down to the house,” he said, ranging up near us. “Then I can take you back. Perhaps I’d better get you out of the way of any other boats first. You don’t mind going over and then back?”

Verplanck looked at Craig. “On the contrary,” muttered Craig, as he made fast the welcome line.

The Carter dock was some three miles from the club on the other side of the bay. As we came up to it, Carter shut off his engine, bent over it a moment, made fast, and left us with a hurried, “Wait here.”

Suddenly, overhead, we heard a peculiar whirring noise that seemed to vibrate through the air. Something huge, black, monster-like, slid down a board runway into the water, traveled a few feet, in white suds and spray, rose in the darkness—and was gone!

As the thing disappeared, I thought I could hear a mocking laugh flung back at us.

“What is it?” I asked, straining my eyes at what had seemed for an instant like a great flying fish with finny tail and huge fins at the sides and above.

“‘Aquaero,’” quoted Kennedy quickly. “Don’t you understand—a hydroaeroplane—a flying boat. There are hundreds of privately owned flying boats now wherever there is navigable water. That was the secret of Carter’s boathouse, of the light we saw in the air.”

“But this Aquaero—who is he?” persisted McNeill. “Carter—Wickham—Australia Mac?”

We looked at each other blankly. No one said a word. We were captured, just as effectively as if we were ironed in a dungeon. There were the black water, the distant lights, which at any other time I should have said would have been beautiful.

Kennedy had sprung into Carter’s boat.

“The deuce,” he exclaimed. “He’s put her out of business.”

Verplanck, chagrined, had been going over his own engine feverishly. “Do you see that?” he asked suddenly, holding up in the light of a lantern a little nut which he had picked out of the complicated machinery. “It never belonged to this engine. Some one placed it there, knowing it would work its way into a vital part with the vibration.”

Who was the person, the only one who could have done it? The answer was on my lips, but I repressed it. Mrs. Verplanck herself had been bending over the engine when last I saw her. All at once it flashed over me that she knew more about the phantom bandit than she had admitted. Yet what possible object could she have had in putting the Streamline out of commission?

My mind was working rapidly, piecing together the fragmentary facts. The remark of Kennedy, long before, instantly assumed new significance. What were the possibilities of blackmail in the right sort of evidence? The yeggman had been after what was more valuable than jewels—letters! Whose? Suddenly I saw the situation. Carter had not been robbed at all. He was in league with the robber. That much was a blind to divert suspicion. He was a lawyer—some one’s lawyer. I recalled the message about letters and evidence, and as I did so there came to mind a picture of Carter and the woman he had been dancing with. In return for his inside information about the jewels of the wealthy homes of Bluffwood, the yeggman was to get something of interest and importance to his client.

The situation called for instant action. Yet what could we do, marooned on the other side of the bay?

From the Club dock a long finger of light swept out into the night, plainly enough near the dock, but diffused and disclosing nothing in the distance. Armand had trained it down the bay in the direction we had taken, but by the time the beam reached us it was so weak that it was lost.

Craig had leaped up on the Carter dock and was capping and uncapping with the brass cover the package which contained the triple mirror.

Still in the distance I could see the wide path of light, aimed toward us, but of no avail.

“What are you doing?” I asked.

“Using the triple mirror to signal to Armand. It is something better than wireless. Wireless requires heavy and complicated apparatus. This is portable, heatless, almost weightless, a source of light depending for its power on another source of light at a great distance.”

I wondered how Armand could ever detect its feeble ray.

“Even in the case of a rolling ship,” Kennedy continued, alternately covering and uncovering the mirror, “the beam of light which this mirror reflects always goes back, unerring, to its source. It would do so from an aeroplane, so high in the air that it could not be located. The returning beam is invisible to anyone not immediately in the path of the ray, and the ray always goes to the observer. It is simply a matter of pure mathematics practically applied. The angle of incidence equals the angle of reflection. There is not a variation of a foot in two miles.”

“What message are you sending him?” asked Verplanck.

“To tell Mrs. Hollingsworth to hurry home immediately,” Kennedy replied, still flashing the letters according to his code.

“Mrs. Hollingsworth?” repeated Verplanck, looking up.

“Yes. This hydroaeroplane yeggman is after something besides jewels to-night. Were those letters that were stolen from you the only ones you had in the safe?”

Verplanck looked up quickly. “Yes, yes. Of course.”

“You had none from a woman—”

“No,” he almost shouted. Of a sudden it seemed to dawn on him what Kennedy was driving at—the robbery of his own house with no loss except of a packet of letters on business, followed by the attempt on Mrs. Hollingsworth. “Do you think I’d keep dynamite, even in the safe?”

To hide his confusion he had turned and was bending again over the engine.

“How is it?” asked Kennedy, his signaling over.

“Able to run on four cylinders and one propeller,” replied Verplanck.

“Then let’s try her. Watch the engine. I’ll take the wheel.”

Limping along, the engine skipping and missing, the once peerless Streamline started back across the bay. Instead of heading toward the club, Kennedy pointed her bow somewhere between that and Verplanck’s.

“I wish Armand would get busy,” he remarked, after glancing now and then in the direction of the club. “What can be the matter?”

“What do you mean?” I asked.

There came the boom as if of a gun far away in the direction in which he was looking, then another.

“Oh, there it is. Good fellow. I suppose he had to deliver my message to Mrs. Hollingsworth himself first.”

From every quarter showed huge balls of fire, rising from the sea, as it were, with a brilliantly luminous flame.

“What is it?” I asked, somewhat startled.

“A German invention for use at night against torpedo and aeroplane attacks. From that mortar Armand has shot half a dozen bombs of phosphide of calcium which are hurled far into the darkness. They are so constructed that they float after a short plunge and are ignited on contact by the action of the salt water itself.”

It was a beautiful pyrotechnic display, lighting up the shore and hills of the bay as if by an unearthly flare.

“There’s that thing now!” exclaimed Kennedy.

In the glow we could see a peculiar, birdlike figure flying through the air over toward the Hollingsworth house. It was the hydroaeroplane.

Out from the little stretch of lawn under the accentuated shadow of the trees, she streaked into the air, swaying from side to side as the pilot operated the stabilizers on the ends of the planes to counteract the puffs of wind off the land.

How could she ever be stopped?

The Streamline, halting and limping, though she was, had almost crossed the bay before the light bombs had been fired by Armand. Every moment brought the flying boat nearer.

She swerved. Evidently the pilot had seen us at last and realized who we were. I was so engrossed watching the thing that I had not noticed that Kennedy had given the wheel to Verplanck and was standing in the bow, endeavoring to sight what looked like a huge gun.

In rapid succession half a dozen shots rang out. I fancied I could almost hear the ripping and tearing of the tough rubber-coated silken wings of the hydroaeroplane as the wind widened the perforation the gun had made.

She had not been flying high, but now she swooped down almost like a gull, seeking to rest on the water. We were headed toward her now, and as the flying boat sank I saw one of the passengers rise in his seat, swing his arm, and far out something splashed in the bay.

On the water, with wings helpless, the flying boat was no match for the Streamline now. She struck at an acute angle, rebounded in the air for a moment, and with a hiss skittered along over the waves, planing with the help of her exhaust under the step of the boat.

There she was, a hull, narrow, scow-bowed, like a hydroplane, with a long pointed stern and a cockpit for two men, near the bow. There were two wide, winglike planes, on a light latticework of wood covered with silk, trussed and wired like a kite frame, the upper plane about five feet above the lower, which was level with the boat deck. We could see the eight-cylindered engine which drove a two-bladed wooden propeller, and over the stern were the air rudder and the horizontal planes. There she was, the hobbled steed now of the phantom bandit who had accomplished the seemingly impossible.

In spite of everything, however, the flying boat reached the shore a trifle ahead of us. As she did so both figures in her jumped, and one disappeared quickly up the bank, leaving the other alone.

“Verplanck, McNeill—get him,” cried Kennedy, as our own boat grated on the beach. “Come, Walter, we’ll take the other one.”

The man had seen that there was no safety in flight. Down the shore he stood, without a hat, his hair blown pompadour by the wind.

As we approached Carter turned superciliously, unbuttoning his bulky khaki life preserver jacket.

“Well?” he asked coolly.

Not for a moment did Kennedy allow the assumed coolness to take him back, knowing that Carter’s delay did not cover the retreat of the other man.

“So,” Craig exclaimed, “you are the—the air pirate?”

Carter disdained to reply.

“It was you who suggested the millionaire households, full of jewels, silver and gold, only half guarded; you, who knew the habits of the people; you, who traded that information in return for another piece of thievery by your partner, Australia Mac—Wickham he called himself here in Bluffwood. It was you—-”

A car drove up hastily, and I noted that we were still on the Hollingsworth estate. Mrs. Hollingsworth had seen us and had driven over toward us.

“Montgomery!” she cried, startled.

“Yes,” said Kennedy quickly, “air pirate and lawyer for Mrs. Verplanck in the suit which she contemplated bringing—”

Mrs. Hollingsworth grew pale under the ghastly, flickering light from the bay.

“Oh!” she cried, realizing at what Kennedy hinted, “the letters!”

“At the bottom of the harbor, now,” said Kennedy. “Mr. Verplanck tells me he has destroyed his. The past is blotted out as far as that is concerned. The future is—for you three to determine. For the present I’ve caught a yeggman and a blackmailer.”

CHAPTER VII
THE WIRELESS WIRETAPPERS

Kennedy did not wait at Bluffwood longer than was necessary. It was easy enough now to silence Montgomery Carter, and the reconciliation of the Verplancks was assured. In the Star I made the case appear at the time to involve merely the capture of Australia Mac.

When I dropped into the office the next day as usual, I found that I had another assignment that would take me out on Long Island. The story looked promising and I was rather pleased to get it.

“Bound for Seaville, I’ll wager,” sounded a familiar voice in my ear, as I hurried up to the train entrance at the Long Island corner of the Pennsylvania Station.

I turned quickly, to find Kennedy just behind me, breathless and perspiring.

“Er—yes,” I stammered in surprise at seeing him so unexpectedly, “but where did you come from? How did you know?”

“Let me introduce Mr. Jack Waldon,” he went on, as we edged our way toward the gate, “the brother of Mrs. Tracy Edwards, who disappeared so strangely from the houseboat Lucie last night at Seaville. That is the case you’re going to write up, isn’t it?”

It was then for the first time that I noticed the excited young man beside Kennedy was really his companion.

I shook hands with Waldon, who gave me a grip that was both a greeting and an added impulse in our general direction through the wicket.

“Might have known the Star would assign you to this Edwards case,” panted Kennedy, mopping his forehead, for the heat in the terminal was oppressive and the crowd, though not large, was closely packed. “Mr. Jameson is my right-hand man,” he explained to Waldon, taking us each by the arm and urging us forward. “Waldon was afraid we might miss the train or I should have tried to get you, Walter, at the office.”

It was all done so suddenly that they quite took away what remaining breath I had, as we settled ourselves to swelter in the smoker instead of in the concourse. I did not even protest at the matter-of-fact assurance with which Craig assumed that his deduction as to my destination was correct.

Waldon, a handsome young fellow in a flannel suit and yachting cap somewhat the worse for his evidently perturbed state of mind, seemed to eye me for the moment doubtfully, in spite of Kennedy’s cordial greeting.

“I’ve had all the first editions of the evening papers,” I hinted as we sped through the tunnel, “but the stories seemed to be quite the same—pretty meager in details.”

“Yes,” returned Waldon with a glance at Kennedy, “I tried to keep as much out of the papers as I could just now for Lucie’s sake.”

“You needn’t fear Jameson,” remarked Kennedy.

He fumbled in his pocket, then paused a moment and shot a glance of inquiry at Waldon, who nodded a mute acquiescence to him.

“There seem to have been a number of very peculiar disappearances lately,” resumed Kennedy, “but this case of Mrs. Edwards is by far the most extraordinary. Of course the Star hasn’t had that—yet,” he concluded, handing me a sheet of notepaper.

“Mr. Waldon didn’t give it out, hoping to avoid scandal.”

I took the paper and read eagerly, in a woman’s hand:

“MY DEAR MISS FOX: I have been down here at Seaville on our houseboat, the Lucie, for several days for a purpose which now is accomplished.

“Already I had my suspicions of you, from a source which I need not name. Therefore, when the Kronprinz got into wireless communication with the station at Seaville I determined through our own wireless on the Lucie to overhear whether there would be any exchange of messages between my husband and yourself.

“I was able to overhear the whole thing and I want you to know that your secret is no longer a secret from me, and that I have already told Mr. Edwards that I know it. You ruin his life by your intimacy which you seem to want to keep up, although you know you have no right to do it, but you shall not ruin mine.

“I am thoroughly disillusioned now. I have not decided on what steps to take, but—”

Only a casual glance was necessary to show me that the writing seemed to grow more and more weak as it progressed, and the note stopped abruptly, as if the writer had been suddenly interrupted or some new idea had occurred to her.

Hastily I tried to figure it out. Lucie Waldon, as everybody knew, was a famous beauty, a marvel of charm and daintiness, slender, with big, soulful, wistful eyes. Her marriage to Tracy Edwards, the wealthy plunger and stockbroker, had been a great social event the year before, and it was reputed at the time that Edwards had showered her with jewels and dresses to the wonder and talk even of society.

As for Valerie Fox, I knew she had won quick recognition and even fame as a dancer in New York during the previous winter, and I recalled reading three or four days before that she had just returned on the Kronprinz from a trip abroad.

“I don’t suppose you have had time to see Miss Fox,” I remarked. “Where is she?”

“At Beach Park now, I think,” replied Waldon, “a resort a few miles nearer the city on the south shore, where there is a large colony of actors.”

I handed back the letter to Kennedy.

“What do you make of it?” he asked, as he folded it up and put it back into his pocket.

“I hardly know what to say,” I replied. “Of course there have been rumors, I believe, that all was not exactly like a honeymoon still with the Tracy Edwardses.”

“Yes,” returned Waldon slowly, “I know myself that there has been some trouble, but nothing definite until I found this letter last night in my sister’s room. She never said anything about it either to mother or myself. They haven’t been much together during the summer, and last night when she disappeared Tracy was in the city. But I hadn’t thought much about it before, for, of course, you know he has large financial interests that make him keep in pretty close touch with New York and this summer hasn’t been a particularly good one on the stock exchange.”

“And,” I put in, “a plunger doesn’t always make the best of husbands. Perhaps there is temperament to be reckoned with here.”

“There seem to be a good many things to be reckoned with,” Craig considered. “For example, here’s a houseboat, the Lucie, a palatial affair, cruising about aimlessly, with a beautiful woman on it. She gives a little party, in the absence of her husband, to her brother, his fiancée and her mother, who visit her from his yacht, the Nautilus. They break up, those living on the Lucie going to their rooms and the rest back to the yacht, which is anchored out further in the deeper water of the bay.

“Some time in the middle of the night her maid, Juanita, finds that she is not in her room. Her brother is summoned back from his yacht and finds that she has left this pathetic, unfinished letter. But otherwise there is no trace of her. Her husband is notified and hurries out there, but he can find no clue. Meanwhile, Mr. Waldon, in despair, hurries down to the city to engage me quietly.”

“You remember I told you,” suggested Waldon, “that my sister hadn’t been feeling well for several days. In fact it seemed that the sea air wasn’t doing her much good, and some one last night suggested that she try the mountains.”

“Had there been anything that would foreshadow the—er—disappearance?” asked Kennedy.

“Only as I say, that for two or three days she seemed to be listless, to be sinking by slow and easy stages into a sort of vacant, moody state of ill health.”

“She had a doctor, I suppose?” I asked.

“Yes, Dr. Jermyn, Tracy’s own personal physician came down from the city several days ago.”

“What did he say?”

“He simply said that it was congestion of the lungs. As far as he could see there was no apparent cause for it. I don’t think he was very enthusiastic about the mountain air idea. The fact is he was like a good many doctors under the circumstances, noncommittal—wanted her under observation, and all that sort of thing.”

“What’s your opinion?” I pressed Craig. “Do you think she has run away?”

“Naturally, I’d rather not attempt to say yet,” Craig replied cautiously. “But there are several possibilities. Yes, she might have left the houseboat in some other boat, of course. Then there is the possibility of accident. It was a hot night. She might have been leaning from the window and have lost her balance. I have even thought of drugs, that she might have taken something in her despondency and have fallen overboard while under the influence of it. Then, of course, there are the two deductions that everyone has made already—either suicide or murder.”

Waldon had evidently been turning something over in his mind.

“There was a wireless outfit aboard the houseboat,” he ventured at length.

“What of that?” I asked, wondering why he was changing the subject so abruptly.

“Why, only this,” he replied. “I have been reading about wireless a good deal lately, and if the theories of some scientists are correct, the wireless age is not without its dangers as well as its wonders. I recall reading not long ago of a German professor who says there is no essential difference between wireless waves and the X-rays, and we know the terrible physical effects of X-rays. I believe he estimated that only one three hundred millionth part of the electrical energy generated by sending a message from one station to another near by is actually used up in transmitting the message. The rest is dispersed in the atmosphere. There must be a good deal of such stray electrical energy about Seaville. Isn’t it possible that it might hit some one somewhere who was susceptible?”

Kennedy said nothing. Waldon’s was at least a novel idea, whether it was plausible or not. The only way to test it out, as far as I could determine, was to see whether it fitted with the facts after a careful investigation of the case itself.

It was still early in the day and the trains were not as crowded as they would be later. Consequently our journey was comfortable enough and we found ourselves at last at the little vine-covered station at Seaville.

One could almost feel that the gay summer colony was in a state of subdued excitement. As we left the quaint station and walked down the main street to the town wharf where we expected some one would be waiting for us, it seemed as if the mysterious disappearance of the beautiful Mrs. Edwards had put a damper on the life of the place. In the hotels there were knots of people evidently discussing the affair, for as we passed we could tell by their faces that they recognized us. One or two bowed and would have joined us, if Waldon had given any encouragement. But he did not stop, and we kept on down the street quickly.

I myself began to feel the spell of mystery about the case as I had not felt it among the distractions of the city. Perhaps I imagined it, but there even seemed to be something strange about the houseboat which we could descry at anchor far down the bay as we approached the wharf.

We were met, as Waldon had arranged, by a high-powered runabout, the tender to his own yacht, a slim little craft of mahogany and brass, driven like an automobile, and capable of perhaps twenty-five or thirty miles an hour. We jumped in and were soon skimming over the waters of the bay like a skipping stone.

It was evident that Waldon was much relieved at having been able to bring assistance, in which he had as much confidence as he reposed in Kennedy. At any rate it was something to be nearing the scene of action again.

The Lucie was perhaps seventy feet long and a most attractive craft, with a hull yachty in appearance and of a type which could safely make long runs along the coast, a stanch, seaworthy boat, of course without the speed of the regularly designed yacht, but more than making up in comfort for those on board what was lost in that way. Waldon pointed out with obvious pride his own trim yacht swinging gracefully at anchor a half mile or so away.

As we approached the houseboat I looked her over carefully. One of the first things I noticed was that there rose from the roof the primitive inverted V aërial of a wireless telegraph. I thought immediately of the unfinished letter and its contents, and shaded my eyes as I took a good look at the powerful transatlantic station on the spit of sand perhaps three or four miles distant, with its tall steel masts of the latest inverted L type and the cluster of little houses below, in which the operators and the plant were.

Waldon noticed what I was looking at, and remarked, “It’s a wonderful station—and well worth a visit, if you have the time—one of the most powerful on the coast, I understand.”

“How did the Lucie come to be equipped with wireless?” asked Craig quickly. “It’s a little unusual for a private boat.”

“Mr. Edwards had it done when she was built,” explained Waldon. “His idea was to use it to keep in touch with the stock market on trips.”

“And it has proved effective?” asked Craig.

“Oh, yes—that is, it was all right last winter when he went on a short cruise down in Florida. This summer he hasn’t been on the boat long enough to use it much.”

“Who operates it?”

“He used to hire a licensed operator, although I believe the engineer, Pedersen, understands the thing pretty well and could use it if necessary.”

“Do you think it was Pedersen who used it for Mrs. Edwards?” asked Kennedy.

“I really don’t know,” confessed Waldon. “Pedersen denies absolutely that he has touched the thing for weeks. I want you to quiz him. I wasn’t able to get him to admit a thing.”

CHAPTER VIII
THE HOUSEBOAT MYSTERY

We had by this time swung around to the side of the houseboat. I realized as we mounted the ladder that the marine gasoline engine had materially changed the old-time houseboat from a mere scow or barge with a low flat house on it, moored in a bay or river, and only with difficulty and expense towed from one place to another. Now the houseboat was really a fair-sized yacht.

The Lucie was built high in order to give plenty of accommodation for the living quarters. The staterooms, dining rooms and saloon were really rooms, with seven or eight feet of head room, and furnished just as one would find in a tasteful and expensive house.

Down in the hull, of course, was the gasoline motor which drove the propeller, so that when the owner wanted a change of scene all that was necessary was to get up anchor, start the motor and navigate the yacht-houseboat to some other harbor.

Edwards himself met us on the deck. He was a tall man, with a red face, a man of action, of outdoor life, apparently a hard worker and a hard player. It was quite evident that he had been waiting for the return of Waldon anxiously.

“You find us considerably upset, Professor Kennedy,” he greeted Craig, as his brother-in-law introduced us.

Edwards turned and led the way toward the saloon. As he entered and bade us be seated in the costly cushioned wicker chairs I noticed how sumptuously it was furnished, and particularly its mechanical piano, its phonograph and the splendid hardwood floor which seemed to invite one to dance in the cool breeze that floated across from one set of open windows to the other. And yet in spite of everything, there was that indefinable air of something lacking, as in a house from which the woman is gone.

“You were not here last night, I understand,” remarked Kennedy, taking in the room at a glance.

“Unfortunately, no,” replied Edwards, “Business has kept me with my nose pretty close to the grindstone this summer. Waldon called me up in the middle of the night, however, and I started down in my car, which enabled me to get here before the first train. I haven’t been able to do a thing since I got here except just wait—wait—wait. I confess that I don’t know what else to do. Waldon seemed to think we ought to have some one down here—and I guess he was right. Anyhow, I’m glad to see you.”

I watched Edwards keenly. For the first time I realized that I had neglected to ask Waldon whether he had seen the unfinished letter. The question was unnecessary. It was evident that he had not.

“Let me see, Waldon, if I’ve got this thing straight,” Edwards went on, pacing restlessly up and down the saloon. “Correct me if I haven’t. Last night, as I understand it, there was a sort of little family party here, you and Miss Verrall and your mother from the Nautilus, and Mrs. Edwards and Dr. Jermyn.”

“Yes,” replied Waldon with, I thought, a touch of defiance at the words “family party.” He paused as if he would have added that the Nautilus would have been more congenial, anyhow, then added, “We danced a little bit, all except Lucie. She said she wasn’t feeling any too well.”

Edwards had paused by the door. “If you’ll excuse me a minute,” he said, “I’ll call Jermyn and Mrs. Edwards’ maid, Juanita. You ought to go over the whole thing immediately, Professor Kennedy.”

“Why didn’t you say anything about the letter to him?” asked Kennedy under his breath.

“What was the use?” returned Waldon. “I didn’t know how he’d take it. Besides, I wanted your advice on the whole thing. Do you want to show it to him?”

“Perhaps it’s just as well,” ruminated Kennedy. “It may be possible to clear the thing up without involving anybody’s name. At any rate, some one is coming down the passage this way.”

Edwards entered with Dr. Jermyn, a clean-shaven man, youthful in appearance, yet approaching middle age. I had heard of him before. He had studied several years abroad and had gained considerable reputation since his return to America.

Dr. Jermyn shook hands with us cordially enough, made some passing comment on the tragedy, and stood evidently waiting for us to disclose our hands.

“You have been Mrs. Edwards’ physician for some time, I believe?” queried Kennedy, fencing for an opening.

“Only since her marriage,” replied the doctor briefly.

“She hadn’t been feeling well for several days, had she?” ventured Kennedy again.

“No,” replied Dr. Jermyn quickly. “I doubt whether I can add much to what you already know. I suppose Mr. Waldon has told you about her illness. The fact is, I suppose her maid Juanita will be able to tell you really more than I can.”

I could not help feeling that Dr. Jermyn showed a great deal of reluctance in talking.

“You have been with her several days, though, haven’t you?”

“Four days, I think. She was complaining of feeling nervous and telegraphed me to come down here. I came prepared to stay over night, but Mr. Edwards happened to run down that day, too, and he asked me if I wouldn’t remain longer. My practice in the summer is such that I can easily leave it with my assistant in the city, so I agreed. Really, that is about all I can say. I don’t know yet what was the matter with Mrs. Edwards, aside from the nervousness which seemed to be of some time standing.”

He stood facing us, thoughtfully stroking his chin, as a very pretty and petite maid nervously entered and stood facing us in the doorway.

“Come in, Juanita,” encouraged Edwards. “I want you to tell these gentlemen just what you told me about discovering that Madame had gone—and anything else that you may recall now.”

“It was Juanita who discovered that Madame was gone, you know,” put in Waldon.

“How did you discover it?” prompted Craig.

“It was very hot,” replied the maid, “and often on hot nights I would come in and fan Madame since she was so wakeful. Last night I went to the door and knocked. There was no reply. I called to her, ‘Madame, madame.’ Still there was no answer. The worst I supposed was that she had fainted. I continued to call.”

“The door was locked?” inquired Kennedy.

“Yes, sir. My call aroused the others on the boat. Dr. Jermyn came and he broke open the door with his shoulder. But the room was empty. Madame was gone.”

“How about the windows?” asked Kennedy.

“Open. They were always open these nights. Sometimes Madame would sit by the window when there was not much breeze.”

“I should like to see the room,” remarked Craig, with an inquiring glance at Edwards.

“Certainly,” he answered, leading the way down a corridor.

Mrs. Edwards’ room was on the starboard side, with wide windows instead of portholes. It was furnished magnificently and there was little about it that suggested the nautical, except the view from the window.

“The bed had not been slept in,” Edwards remarked as we looked about curiously.

Kennedy walked over quickly to the wide series of windows before which was a leather-cushioned window seat almost level with the window, several feet above the level of the water. It was by this window, evidently, that Juanita meant that Mrs. Edwards often sat. It was a delightful position, but I could readily see that it would be comparatively easy for anyone accidentally or purposely to fall.

“I think myself,” Waldon remarked to Kennedy, “that it must have been from the open window that she made her way to the outside. It seems that all agree that the door was locked, while the window was wide open.”

“There had been no sound—no cry to alarm you?” shot out Kennedy suddenly to Juanita.

“No, sir, nothing. I could not sleep myself, and I thought of Madame.”

“You heard nothing?” he asked of Dr. Jermyn.

“Nothing until I heard the maid call,” he replied briefly.

Mentally I ran over again Kennedy’s first list of possibilities—taken off by another boat, accident, drugs, suicide, murder.

Was there, I asked myself, sufficient reason for suicide? The letter seemed to me to show too proud a spirit for that. In fact the last sentence seemed to show that she was contemplating the surest method of revenge, rather than surrender. As for accident, why should a person fall overboard from a large houseboat into a perfectly calm harbor? Then, too, there had been no outcry. Somehow, I could not seem to fit any of the theories in with the facts. Evidently it was like many another case, one in which we, as yet, had insufficient data for a conclusion.

Suddenly I recalled the theory that Waldon himself had advanced regarding the wireless, either from the boat itself or from the wireless station. For the moment, at least, it seemed plausible that she might have been seated at the window, that she might have been affected by escaped wireless, or by electrolysis. I knew that some physicians had described a disease which they attributed to wireless, a sort of anemia with a marked diminution in the number of red corpuscles in the blood, due partly to the over etherization of the air by reason of the alternating currents used to generate the waves.

“I should like now to inspect the little wireless plant you have here on the Lucie,” remarked Kennedy. “I noticed the mast as we were approaching a few minutes ago.”

I had turned at the sound of his voice in time to catch Edwards and Dr. Jermyn eyeing each other furtively. Did they know about the letter, after all, I wondered? Was each in doubt about just how much the other knew?

There was no time to pursue these speculations. “Certainly,” agreed Mr. Edwards promptly, leading the way.

Kennedy seemed keenly interested in inspecting the little wireless plant, which was of a curious type and not exactly like any that I had seen before.

“Wireless apparatus,” he remarked, as he looked it over, “is divided into three parts, the source of power whether battery or dynamo, the making and sending of wireless waves, including the key, spark, condenser and tuning coil, and the receiving apparatus, head telephones, antennae, ground and detector.”

Pedersen, the engineer, came in while we were looking the plant over, but seemed uncommunicative to all Kennedy’s efforts to engage him in conversation.

“I see,” remarked Kennedy, “that it is a very compact system with facilities for a quick change from one wave length to another.”

“Yes,” grunted Pedersen, as averse to talking, evidently, as others on the Lucie.

“Spark gap, quenched type,” I heard Kennedy mutter almost to himself, with a view to showing Pedersen that he knew something about it. “Break system relay—operator can overhear any interference while transmitting—transformation by a single throw of a six-point switch which tunes the oscillating and open circuits to resonance. Very clever—very efficient. By the way, Pedersen, are you the only person aboard who can operate this?”

“How should I know?” he answered almost surlily.

“You ought to know, if anybody,” answered Kennedy unruffled. “I know that it has been operated within the past few days.”

Pedersen shrugged his shoulders. “You might ask the others aboard,” was all he said. “Mr. Edwards pays me to operate it only for himself, when he has no other operator.”

Kennedy did not pursue the subject, evidently from fear of saying too much just at present.

“I wonder if there is anyone else who could have operated it,” said Waldon, as we mounted again to the deck.

“I don’t know,” replied Kennedy, pausing on the way up. “You haven’t a wireless on the Nautilus, have you?”

Waldon shook his head. “Never had any particular use for it myself,” he answered.

“You say that Miss Verrall and her mother have gone back to the city?” pursued Kennedy, taking care that as before the others were out of earshot.

“Yes.”

“I’d like to stay with you tonight, then,” decided Kennedy. “Might we go over with you now? There doesn’t seem to be anything more I can do here, unless we get some news about Mrs. Edwards.”

Waldon seemed only too glad to agree, and no one on the Lucie insisted on our staying.

We arrived at the Nautilus a few minutes later, and while we were lunching Kennedy dispatched the tender to the Marconi station with a note.

It was early in the afternoon when the tender returned with several packages and coils of wire. Kennedy immediately set to work on the Nautilus stretching out some of the wire.

“What is it you are planning?” asked Waldon, to whom every action of Kennedy seemed to be a mystery of the highest interest.

“Improvising my own wireless,” he replied, not averse to talking to the young man to whom he seemed to have taken a fancy. “For short distances, you know, it isn’t necessary to construct an aërial pole or even to use outside wires to receive messages. All that is needed is to use just a few wires stretched inside a room. The rest is just the apparatus.”

I was quite as much interested as Waldon. “In wireless,” he went on, “the signals are not sent in one direction, but in all, so that a person within range of the ethereal disturbance can get them if only he has the necessary receiving apparatus. This apparatus need not be so elaborate and expensive as used to be thought needful if a sensitive detector is employed, and I have sent over to the station for a new piece of apparatus which I knew they had in almost any Marconi station. Why, I’ve got wireless signals using only twelve feet of number eighteen copper wire stretched across a room and grounded with a water pipe. You might even use a wire mattress on an iron bedstead.”

“Can’t they find out by—er, interference?” I asked, repeating the term I had so often heard.

Kennedy laughed. “No, not for radio apparatus which merely receives radiograms and is not equipped for sending. I am setting up only one side of a wireless outfit here. All I want to do is to hear what is being said. I don’t care about saying anything.”

He unwrapped another package which had been loaned to him by the radio station and we watched him curiously as he tested it and set it up. Some parts of it I recognized such as the very sensitive microphone, and another part I could have sworn was a phonograph cylinder, though Craig was so busy testing his apparatus that now we could not ask questions.

It was late in the afternoon when he finished, and we had just time to run up to the dock at Seaville and stop off at the Lucie to see if anything had happened in the intervening hours before dinner. There was nothing, except that I found time to file a message to the Star and meet several fellow newspaper men who had been sent down by other papers on the chance of picking up a good story.

We had the Nautilus to ourselves, and as she was a very comfortable little craft, we really had a very congenial time, a plunge over her side, a good dinner, and then a long talk out on deck under the stars, in which we went over every phase of the case. As we discussed it, Waldon followed keenly, and it was quite evident from his remarks that he had come to the conclusion that Dr. Jermyn at least knew more than he had told about the case.

Still, the day wore away with no solution yet of the mystery.

CHAPTER IX
THE RADIO DETECTIVE

It was early the following morning when a launch drew up beside the Nautilus. In it were Edwards and Dr. Jermyn, wildly excited.

“What’s the matter?” called out Waldon.

“They—they have found the body,” Edwards blurted out.

Waldon paled and clutched the rail. He had thought the world of his sister, and not until the last moment had he given up hope that perhaps she might be found to have disappeared in some other way than had become increasingly evident.

“Where?” cried Kennedy. “Who?”

“Over on Ten Mile Beach,” answered Edwards. “Some fishermen who had been out on a cruise and hadn’t heard the story. They took the body to town, and there it was recognized. They sent word out to us immediately.”

Waldon had already spun the engine of his tender, which was about the fastest thing afloat about Seaville, had taken Edwards over, and we were off in a cloud of spray, the nose of the boat many inches above the surface of the water.

In the little undertaking establishment at Seaville lay the body of the beautiful young matron about whom so much anxiety had been felt. I could not help thinking what an end was this for the incomparable beauty. At the very height of her brief career the poor little woman’s life had been suddenly snuffed out. But by what? The body had been found, but the mystery had been far from solved.

As Kennedy bent over the body, I heard him murmur to himself, “She had everything—everything except happiness.”

“Was it drowning that caused her death?” asked Kennedy of the local doctor, who also happened to be coroner and had already arrived on the scene.

The doctor shook his head. “I don’t know,” he said doubtfully. “There was congestion of the lungs—but I—I can’t say but what she might have been dead before she fell or was thrown into the water.”

Dr. Jermyn stood on one side, now and then putting in a word, but for the most part silent unless spoken to. Kennedy, however, was making a most minute examination.

As he turned the beautiful head, almost reverently, he saw something that evidently attracted his attention. I was standing next to him and, between us, I think we cut off the view of the others. There on the back of the neck, carefully, had been smeared something transparent, almost skin-like, which had easily escaped the attention of the rest.

Kennedy tried to pick it off, but only succeeded in pulling off a very minute piece to which the flesh seemed to adhere.

“That’s queer,” he whispered to me. “Water, naturally, has no effect on it, else it would have been washed off long before. Walter,” he added, “just slip across the street quietly to the drug store and get me a piece of gauze soaked with acetone.”

As quickly and unostentatiously as I could I did so and handed him the wet cloth, contriving at the same time to add Waldon to our barrier, for I could see that Kennedy was anxious to be observed as little as possible.

“What is it?” I whispered, as he rubbed the transparent skin-like stuff off, and dropped the gauze into his pocket.

“A sort of skin varnish,” he remarked under his breath, “waterproof and so adhesive that it resists pulling off even with a knife without taking the cuticle with it.”

Beneath, as the skin varnish slowly dissolved under his gentle rubbing, he had disclosed several very small reddish spots, like little cuts that had been made by means of a very sharp instrument. As he did so, he gave them a hasty glance, turned the now stony beautiful head straight again, stood up, and resumed his talk with the coroner, who was evidently getting more and more bewildered by the case.

Edwards, who had completed the arrangements with the undertaker for the care of the body as soon as the coroner released it, seemed completely unnerved.

“Jermyn,” he said to the doctor, as he turned away and hid his eyes, “I can’t stand this. The undertaker wants some stuff from the—er—boat,” his voice broke over the name which had been hers. “Will you get it for me? I’m going up to a hotel here, and I’ll wait for you there. But I can’t go out to the boat—yet.”

“I think Mr. Waldon will be glad to take you out in his tender,” suggested Kennedy. “Besides, I feel that I’d like a little fresh air as a bracer, too, after such a shock.”

“What were those little cuts?” I asked as Waldon and Dr. Jermyn preceded us through the crowd outside to the pier.

“Some one,” he answered in a low tone, “has severed the pneumogastric nerves.”

“The pneumogastric nerves?” I repeated.

“Yes, the vagus or wandering nerve, the so-called tenth cranial nerve. Unlike the other cranial nerves, which are concerned with the special senses or distributed to the skin and muscles of the head and neck, the vagus, as its name implies, strays downward into the chest and abdomen supplying branches to the throat, lungs, heart and stomach and forms an important connecting link between the brain and the sympathetic nervous system.”

We had reached the pier, and a nod from Kennedy discouraged further conversation on the subject.

A few minutes later we had reached the Lucie and gone up over her side. Kennedy waited until Jermyn had disappeared into the room of Mrs. Edwards to get what the undertaker had desired. A moment and he had passed quietly into Dr. Jermyn’s own room, followed by me. Several quick glances about told him what not to waste time over, and at last his eye fell on a little portable case of medicines and surgical instruments. He opened it quickly and took out a bottle of golden yellow liquid.

Kennedy smelled it, then quickly painted some on the back of his hand. It dried quickly, like an artificial skin. He had found a bottle of skin varnish in Dr. Jermyn’s own medicine chest!

We hurried back to the deck, and a few minutes later the doctor appeared with a large package.

“Did you ever hear of coating the skin by a substance which is impervious to water, smooth and elastic?” asked Kennedy quietly as Waldon’s tender sped along back to Seaville.

“Why—er, yes,” he said frankly, raising his eyes and looking at Craig in surprise. “There have been a dozen or more such substances. The best is one which I use, made of pyroxylin, the soluble cotton of commerce, dissolved in amyl acetate and acetone with some other substances that make it perfectly sterile. Why do you ask?”

“Because some one has used a little bit of it to cover a few slight cuts on the back of the neck of Mrs. Edwards.”

“Indeed?” he said simply, in a tone of mild surprise.

“Yes,” pursued Kennedy. “They seem to me to be subcutaneous incisions of the neck with a very fine scalpel dividing the two great pneumogastric nerves. Of course you know what that would mean—the victim would pass away naturally by slow and easy stages in three or four days, and all that would appear might be congestion of the lungs. They are delicate little punctures and elusive nerves to locate, but after all it might be done as painlessly, as simply and as safely as a barber might remove some dead hairs. A country coroner might easily pass over such evidence at an autopsy—especially if it was concealed by skin varnish.”

I was surprised at the frankness with which Kennedy spoke, but absolutely amazed at the coolness of Jermyn. At first he said absolutely nothing. He seemed to be as set in his reticence as he had been when we first met.

I watched him narrowly. Waldon, who was driving the boat, had not heard what was said, but I had, and I could not conceive how anyone could take it so calmly.

Finally Jermyn turned to Kennedy and looked him squarely in the eye. “Kennedy,” he said slowly, “this is extraordinary—most extraordinary,” then, pausing, added, “if true.”

“There can be no doubt of the truth,” replied Kennedy, eyeing Dr. Jermyn just as squarely.

“What do you propose to do about it?” asked the doctor.

“Investigate,” replied Kennedy simply. “While Waldon takes these things up to the undertaker’s, we may as well wait here in the boat. I want him to stop on the way back for Mr. Edwards. Then we shall go out to the Lucie. He must go, whether he likes it or not.”

It was indeed a most peculiar situation as Kennedy and I sat in the tender with Dr. Jermyn waiting for Waldon to return with Edwards. Not a word was spoken.

The tenseness of the situation was not relieved by the return of Waldon with Edwards. Waldon seemed to realize without knowing just what it was, that something was about to happen. He drove his boat back to the Lucie again in record time. This was Kennedy’s turn to be reticent. Whatever it was he was revolving in his mind, he answered in scarcely more than monosyllables whatever questions were put to him.

“You are not coming aboard?” inquired Edwards in surprise as he and Jermyn mounted the steps of the houseboat ladder, and Kennedy remained seated in the tender.

“Not yet,” replied Craig coolly.

“But I thought you had something to show me. Waldon told me you had.”

“I think I shall have in a short time,” returned Kennedy. “We shall be back immediately. I’m just going to ask Waldon to run over to the Nautilus for a few minutes. We’ll tow back your launch, too, in case you need it.”

Waldon had cast off obediently.

“There’s one thing sure,” I remarked. “Jermyn can’t get away from the Lucie until we return—unless he swims.”

Kennedy did not seem to pay much attention to the remark, for his only reply was: “I’m taking a chance by this maneuvering, but I think it will work out that I am correct. By the way, Waldon, you needn’t put on so much speed. I’m in no great hurry to get back. Half an hour will be time enough.”

“Jermyn? What did you mean by Jermyn?” asked Waldon, as we climbed to the deck of the Nautilus.

He had evidently learned, as I had, that it was little use to try to quiz Kennedy until he was ready to be questioned and had decided to try it on me.

I had nothing to conceal and I told him quite fully all that I knew. Actually, I believe if Jermyn had been there, it would have taken both Kennedy and myself to prevent violence. As it was I had a veritable madman to deal with while Kennedy gathered up leisurely the wireless outfit he had installed on the deck of Waldon’s yacht. It was only by telling him that I would certainly demand that Kennedy leave him behind if he did not control his feelings that I could calm him before Craig had finished his work on the yacht.

Waldon relieved himself by driving the tender back at top speed to the Lucie, and now it seemed that Kennedy had no objection to traveling as fast as the many-cylindered engine was capable of going.

As we entered the saloon of the houseboat, I kept close watch over Waldon.

Kennedy began by slipping a record on the phonograph in the corner of the saloon, then facing us and addressing Edwards particularly.

“You may be interested to know, Mr. Edwards,” he said, “that your wireless outfit here has been put to a use for which you never intended it.”

No one said anything, but I am sure that some one in the room then for the first time began to suspect what was coming.

“As you know, by the use of an aërial pole, messages may be easily received from any number of stations,” continued Craig. “Laws, rules and regulations may be adopted to shut out interlopers and plug busybody ears, but the greater part of whatever is transmitted by the Hertzian waves can be snatched down by other wireless apparatus.

“Down below, in that little room of yours,” went on Craig, “might sit an operator with his ear-phone clamped to his head, drinking in the news conveyed surely and swiftly to him through the wireless signals—plucking from the sky secrets of finance and,” he added, leaning forward, “love.”

In his usual dramatic manner Kennedy had swung his little audience completely with him.

“In other words,” he resumed, “it might be used for eavesdropping by a wireless wiretapper. Now,” he concluded, “I thought that if there was any radio detective work being done, I might as well do some, too.”

He toyed for a moment with the phonograph record. “I have used,” he explained, “Marconi’s radiotelephone, because in connection with his receivers Marconi uses phonographic recorders and on them has captured wireless telegraph signals over hundreds of miles.

“He has found that it is possible to receive wireless signals, although ordinary records are not loud enough, by using a small microphone on the repeating diaphragm and connected with a loud-speaking telephone. The chief difficulty was to get a microphone that would carry a sufficient current without burning up. There were other difficulties, but they have been surmounted and now wireless telegraph messages may be automatically recorded and made audible.”

Kennedy started the phonograph, running it along, stopping it, taking up the record at a new point.

“Listen,” he exclaimed at length, “there’s something interesting, the WXY call—Seaville station—from some one on the Lucie only a few minutes ago, sending a message to be relayed by Seaville to the station at Beach Park. It seems impossible, but buzzing and ticking forth is this message from some one off this very houseboat. It reads: “Miss Valerie Fox, Beach Park. I am suspected of the murder of Mrs. Edwards. I appeal to you to help me. You must allow me to tell the truth about the messages I intercepted for Mrs. Edwards which passed between yourself on the ocean and Mr. Edwards in New York via Seaville. You rejected me and would not let me save you. Now you must save me.”

Kennedy paused, then added, “The message is signed by Dr. Jermyn!”

At once I saw it all. Jermyn had been the unsuccessful suitor for Miss Fox’s affections. But before I could piece out the rest of the tragic story, Kennedy had started the phonograph record at an earlier point which he had skipped for the present.

“Here’s another record—a brief one—also to Valerie Fox from the houseboat: ‘Refuse all interviews. Deny everything. Will see you as soon as present excitement dies down.’”

Before Kennedy could finish, Waldon had leaped forward, unable longer to control his feelings. If Kennedy had not seized his arm, I verily believe he would have cast Dr. Jermyn into the bay into which his sister had fallen two nights before in her terribly weakened condition.

“Waldon,” cried Kennedy, “for God’s sake, man—wait! Don’t you understand? The second message is signed Tracy Edwards.”

It came as quite as much a shock of surprise to me as to Waldon.

“Don’t you understand?” he repeated. “Your sister first learned from Dr. Jermyn what was going on. She moved the Lucie down here near Seaville in order to be near the wireless station when the ship bearing her rival, Valerie Fox, got in touch with land. With the help of Dr. Jermyn she intercepted the wireless messages from the Kronprinz to the shore—between her husband and Valerie Fox.”

Kennedy was hurrying on now to his irresistible conclusion. “She found that he was infatuated with the famous stage beauty, that he was planning to marry another, her rival. She accused him of it, threatened to defeat his plans. He knew she knew his unfaithfulness. Instead of being your sister’s murderer, Dr. Jermyn was helping her get the evidence that would save both her and perhaps win Miss Fox back to himself.”

Kennedy had turned sharply on Edwards.

“But,” he added, with a glance that crushed any lingering hope that the truth had been concealed, “the same night that Dr. Jermyn arrived here, you visited your wife. As she slept you severed the nerves that meant life or death to her. Then you covered the cuts with the preparation which you knew Dr. Jermyn used. You asked him to stay, while you went away, thinking that when death came you would have a perfect alibi—perhaps a scapegoat. Edwards, the radio detective convicts you!”

CHAPTER X
THE CURIO SHOP

Edwards crumpled up as Kennedy and I faced him. There was no escape. In fact our greatest difficulty was to protect him from Waldon.

Kennedy’s work in the case was over when we had got Edwards ashore and in the hands of the authorities. But mine had just begun and it was late when I got my story on the wire for the Star.

I felt pretty tired and determined to make up for it by sleeping the next day. It was no use, however.

“Why, what’s the matter, Mrs. Northrop?” I heard Kennedy ask as he opened our door the next morning, just as I had finished dressing.

He had admitted a young woman, who greeted us with nervous, wide-staring eyes.

“It’s—it’s about Archer,” she cried, sinking into the nearest chair and staring from one to the other of us.

She was the wife of Professor Archer Northrop, director of the archeological department at the university. Both Craig and I had known her ever since her marriage to Northrop, for she was one of the most attractive ladies in the younger set of the faculty, to which Craig naturally belonged. Archer had been of the class below us in the university. We had hazed him, and out of the mild hazing there had, strangely enough, grown a strong friendship.

I recollected quickly that Northrop, according to last reports, had been down in the south of Mexico on an archeological expedition. But before I could frame, even in my mind, the natural question in a form that would not alarm his wife further, Kennedy had it on his lips.

“No bad news from Mitla, I hope?” he asked gently, recalling one of the main working stations chosen by the expedition and the reported unsettled condition of the country about it. She looked up quickly.

“Didn’t you know—he—came back from Vera Cruz yesterday?” she asked slowly, then added, speaking in a broken tone, “and—he seems—suddenly—to have disappeared. Oh, such a terrible night of worry! No word—and I called up the museum, but Doctor Bernardo, the curator, had gone, and no one answered. And this morning—I couldn’t stand it any longer—so I came to you.”

“You have no idea, I suppose, of anything that was weighing on his mind?” suggested Kennedy.

“No,” she answered promptly.

In default of any further information, Kennedy did not pursue this line of questioning. I could not determine from his face or manner whether he thought the matter might involve another than Mrs. Northrop, or, perhaps, something connected with the unsettled condition of the country from which her husband had just arrived.

“Have you any of the letters that Archer wrote home?” asked Craig, at length.

“Yes,” she replied eagerly, taking a little packet from her handbag. “I thought you might ask that. I brought them.”

“You are an ideal client,” commented Craig encouragingly, taking the letters. “Now, Mrs. Northrop, be brave. Trust me to run this thing down, and if you hear anything let me know immediately.”

She left us a moment later, visibly relieved.

Scarcely had she gone when Craig, stuffing the letters into his pocket unread, seized his hat, and a moment later was striding along toward the museum with his habitual rapid, abstracted step which told me that he sensed a mystery.

In the museum we met Doctor Bernardo, a man slightly older than Northrop, with whom he had been very intimate. He had just arrived and was already deeply immersed in the study of some new and beautiful colored plates from the National Museum of Mexico City.

“Do you remember seeing Northrop here yesterday afternoon?” greeted Craig, without explaining what had happened.

“Yes,” he answered promptly. “I was here with him until very late. At least, he was in his own room, working hard, when I left.”

“Did you see him go?”

“Why—er—no,” replied Bernardo, as if that were a new idea. “I left him here—at least, I didn’t see him go out.”

Kennedy tried the door of Northrop’s room, which was at the far end, in a corner, and communicated with the hall only through the main floor of the museum. It was locked. A pass-key from the janitor quickly opened it.

Such a sight as greeted us, I shall never forget. There, in his big desk-chair, sat Northrop, absolutely rigid, the most horribly contorted look on his features that I have ever seen—half of pain, half of fear, as if of something nameless.

Kennedy bent over. His hands were cold.

Northrop had been dead at least twelve hours, perhaps longer. All night the deserted museum had guarded its terrible secret.

As Craig peered into his face, he saw, in the fleshy part of the neck, just below the left ear, a round red mark, with just a drop or two of now black coagulated blood in the center. All around we could see a vast amount of miscellaneous stuff, partly unpacked, partly just opened, and waiting to be taken out of the wrappings by the now motionless hands.

“I suppose you are more or less familiar with what Northrop brought back?” asked Kennedy of Bernardo, running his eye over the material in the room.

“Yes, reasonably,” answered Bernardo. “Before the cases arrived from the wharf, he told me in detail what he had managed to bring up with him.”

“I wish, then, that you would look it over and see if there is anything missing,” requested Craig, already himself busy in going over the room for other evidence.

Doctor Bernardo hastily began taking a mental inventory of the stuff. While they worked, I tried vainly to frame some theory which would explain the startling facts we had so suddenly discovered.

Mitla, I knew, was south of the city of Oaxaca, and there, in its ruined palaces, was the crowning achievement of the old Zapotec kings. No ruins in America were more elaborately ornamented or richer in lore for the archeologist.

Northrop had brought up porphyry blocks with quaint grecques and much hieroglyphic painting. Already unpacked were half a dozen copper axes, some of the first of that particular style that had ever been brought to the United States. Besides the sculptured stones and the mosaics were jugs, cups, vases, little gods, sacrificial stones—enough, almost, to equip a new alcove in the museum.

Before Northrop was an idol, a hideous thing on which frogs and snakes squatted and coiled. It was a fitting piece to accompany the gruesome occupant of the little room in his long, last vigil. In fact, it almost sent a shudder over me, and if I had been inclined to the superstitious, I should certainly have concluded that this was retribution for having disturbed the lares and penates of a dead race.

Doctor Bernardo was going over the material a second time. By the look on his face, even I could guess that something was missing.

“What is it?” asked Craig, following the curator closely.

“Why,” he answered slowly, “there was an inscription—we were looking at it earlier in the day—on a small block of porphyry. I don’t see it.”

He paused and went back to his search before we could ask him further what he thought the inscription was about.

I thought nothing myself at the time of his reticence, for Kennedy had gone over to a window back of Northrop and to the left. It was fully twenty feet from the downward slope of the campus there, and, as he craned his neck out, he noted that the copper leader of the rain pipe ran past it a few feet away.

I, too, looked out. A thick group of trees hid the window from the avenue beyond the campus wall, and below us, at a corner of the building, was a clump of rhododendrons. As Craig bent over the sill, he whipped out a pocket lens.

A moment later he silently handed the glass to me. As nearly as I could make out, there were five marks on the dust of the sill.

“Finger-prints!” I exclaimed. “Some one has been clinging to the edge of the ledge.”

“In that case,” Craig observed quietly, “there would have been only four prints.”

I looked again, puzzled. The prints were flat and well separated.

“No,” he added, “not finger-prints—toe-prints.”

“Toe-prints?” I echoed.

Before he could reply, Craig had dashed out of the room, around, and under the window. There, he was carefully going over the soft earth around the bushes below.

“What are you looking for?” I asked, joining him.

“Some one—perhaps two—has been here,” he remarked, almost under his breath. “One, at least, has removed his shoes. See those shoe-prints up to this point? The print of a boot-heel in soft earth shows the position and contour of every nail head. Bertillon has made a collection of such nails, certain types, sizes, and shapes used in certain boots, showing often what country the shoes came from. Even the number and pattern are significant. Some factories use a fixed number of nails and arrange them in a particular manner. I have made my own collection of such prints in this country. These were American shoes. Perhaps the clue will not lead us anywhere, though, for I doubt whether it was an American foot.”

Kennedy continued to study the marks.

“He removed his shoes—either to help in climbing or to prevent noise—ah—here’s the foot! Strange—see how small it is—and broad, how prehensile the toes—almost like fingers. Surely that foot could never have been encased in American shoes all its life. I shall make plaster casts of these, to preserve later.”

He was still scouting about on hands and knees in the dampness of the rhododendrons. Suddenly he reached his long arm in among the shrubs and picked up a little reed stick. On the end of it was a small cylinder of buff brown.

He looked at it curiously, dug his nail into the soft mass, then rubbed his nail over the tip of his tongue gingerly.

With a wry face, as if the taste were extremely acrid, he moistened his handkerchief and wiped off his tongue vigorously.

“Even that minute particle that was on my nail makes my tongue tingle and feel numb,” he remarked, still rubbing. “Let us go back again. I want to see Bernardo.”

“Had he any visitors during the day?” queried Kennedy, as he reentered the ghastly little room, while the curator stood outside, completely unnerved by the tragedy which had been so close to him without his apparently knowing it. Kennedy was squeezing out from the little wound on Northrop’s neck a few drops of liquid on a sterilized piece of glass.

“No; no one,” Bernardo answered, after a moment.

“Did you see anyone in the museum who looked suspicious?” asked Kennedy, watching Bernardo’s face keenly.

“No,” he hesitated. “There were several people wandering about among the exhibits, of course. One, I recall, late in the afternoon, was a little dark-skinned woman, rather good-looking.”

“A Mexican?”

“Yes, I should say so. Not of Spanish descent, though. She was rather of the Indian type. She seemed to be much interested in the various exhibits, asked me several questions, very intelligently, too. Really, I thought she was trying to—er—flirt with me.”

He shot a glance at Craig, half of confession, half of embarrassment.

“And—oh, yes—there was another—a man, a little man, as I recall, with shaggy hair. He looked like a Russian to me. I remember, because he came to the door, peered around hastily, and went away. I thought he might have got into the wrong part of the building and went to direct him right—but before I could get out into the hall, he was gone. I remember, too, that, as I turned, the woman had followed me and soon was asking other questions—which, I will admit—I was glad to answer.”

“Was Northrop in his room while these people were here?”

“Yes; he had locked the door so that none of the students or visitors could disturb him.”

“Evidently the woman was diverting your attention while the man entered Northrop’s room by the window,” ruminated Craig, as we stood for a moment in the outside doorway.

He had already telephoned to our old friend Doctor Leslie, the coroner, to take charge of the case, and now was ready to leave. The news had spread, and the janitor of the building was waiting to lock the campus door to keep back the crowd of students and others.

Our next duty was the painful one of breaking the news to Mrs. Northrop. I shall pass it over. Perhaps no one could have done it more gently than Kennedy. She did not cry. She was simply dazed. Fortunately her mother was with her, had been, in fact, ever since Northrop had gone on the expedition.

“Why should anyone want to steal tablets of old Mixtec inscriptions?” I asked thoughtfully, as we walked sadly over the campus in the direction of the chemistry building. “Have they a sufficient value, even on appreciative Fifth Avenue, to warrant murder?”

“Well,” he remarked, “it does seem incomprehensible. Yet people do just such things. The psychologists tell us that there is a veritable mania for possessing such curios. However, it is possible that there may be some deeper significance in this case,” he added, his face puckered in thought.

Who was the mysterious Mexican woman, who the shaggy Russian? I asked myself. Clearly, at least, if she existed at all, she was one of the millions not of Spanish but of Indian descent in the country south of us. As I reasoned it out, it seemed to me as if she must have been an accomplice. She could not have got into Northrop’s room either before or after Doctor Bernardo left. Then, too, the toe-and shoe-prints were not hers. But, I figured, she certainly had a part in the plot.

While I was engaged in the vain effort to unravel the tragic affair by pure reason, Kennedy was at work with practical science.

He began by examining the little dark cylinder on the end of the reed. On a piece of the stuff, broken off, he poured a dark liquid from a brown-glass bottle. Then he placed it under a microscope.

“Microscopically,” he said slowly, “it consists almost wholly of minute, clear granules which give a blue reaction with iodine. They are starch. Mixed with them are some larger starch granules, a few plant cells, fibrous matter, and other foreign particles. And then, there is the substance that gives that acrid, numbing taste.” He appeared to be vacantly studying the floor.

“What do you think it is?” I asked, unable to restrain myself.

“Aconite,” he answered slowly, “of which the active principle is the deadly poisonous alkaloid, aconitin.”

He walked over and pulled down a well-thumbed standard work on toxicology, turned the pages, then began to read aloud:

Pure aconitin is probably the most actively poisonous substance with which we are acquainted and, if administered hypodermically, the alkaloid is even more powerfully poisonous than when taken by the mouth.

As in the case of most of the poisonous alkaloids, aconitin does not produce any decidedly characteristic post-mortem appearances. There is no way to distinguish it from other alkaloids, in fact, no reliable chemical test. The physiological effects before death are all that can be relied on.

Owing to its exceeding toxic nature, the smallness of the dose required to produce death, and the lack of tests for recognition, aconitin possesses rather more interest in legal medicine than most other poisons.

It is one of the few substances which, in the present state of toxicology, might be criminally administered and leave no positive evidence of the crime. If a small but fatal dose of the poison were to be given, especially if it were administered hypodermically, the chances of its detection in the body after death would be practically none.

CHAPTER XI
THE “PILLAR OF DEATH”

I was looking at him fixedly as the diabolical nature of what must have happened sank into my mind. Here was a poison that defied detection. I could see by the look on Craig’s face that that problem, alone, was enough to absorb his attention. He seemed fully to realize that we had to deal with a criminal so clever that he might never be brought to justice.

An idea flashed over me.

“How about the letters?” I suggested.

“Good, Walter!” he exclaimed.

He untied the package which Mrs. Northrop had given him and glanced quickly over one after another of the letters.

“Ah!” he exclaimed, fairly devouring one dated at Mitla. “Listen—it tells about Northrop’s work and goes on:

“‘I have been much interested in a cavern, or subterraneo, here, in the shape of a cross, each arm of which extends for some twelve feet underground. In the center it is guarded by a block of stone popularly called “the Pillar of Death.” There is a superstition that whoever embraces it will die before the sun goes down.

“‘From the subterraneo is said to lead a long, underground passage across the court to another subterranean chamber which is full of Mixtec treasure. Treasure hunters have dug all around it, and it is said that two old Indians, only, know of the immense amount of buried gold and silver, but that they will not reveal it.’”

I started up. Here was the missing link which I had been waiting for.

“There, at least, is the motive,” I blurted out. “That is why Bernardo was so reticent. Northrop, in his innocence of heart, had showed him that inscription.”

Kennedy said nothing as he finally tied up the little packet of letters and locked it in his safe. He was not given to hasty generalizations; neither was he one who clung doggedly to a preconceived theory.

It was still early in the afternoon. Craig and I decided to drop into the museum again in order to see Doctor Bernardo. He was not there and we sat down to wait.

Just then the letter box in the door clicked. It was the postman on his rounds. Kennedy walked over and picked up the letter.

The postmark bore the words, “Mexico City,” and a date somewhat later than that on which Northrop had left Vera Cruz. In the lower corner, underscored, were the words, “Personal—Urgent.”

“I’d like to know what is in that,” remarked Craig, turning it over and over.

He appeared to be considering something, for he rose suddenly and shoved the letter into his pocket.

I followed, and a few moments later, across the campus in his laboratory, he was working quickly over an X-ray apparatus. He had placed the letter in it.

“These are what are known as ‘low’ tubes,” he explained. “They give out ‘soft rays.’” He continued to work for a few moments, then handed me the letter.

“Now, Walter,” he said, “if you will just hurry back to the museum and replace that letter, I think I will have something that will astonish you—though whether it will have any bearing on the case, remains to be seen.”

“What is it?” I asked, a few minutes later, when I had rejoined him, after returning the letter. He was poring intently over what looked like a negative.

“The possibility of reading the contents of documents inclosed in a sealed envelope,” he replied, still studying the shadowgraph closely, “has already been established by the well-known English scientist, Doctor Hall Edwards. He has been experimenting with the method of using X-rays recently discovered by a German scientist, by which radiographs of very thin substances, such as a sheet of paper, a leaf, an insect’s body, may be obtained. These thin substances through which the rays used formerly to pass without leaving an impression, can now be radiographed.”

I looked carefully as he traced out something on the negative. On it was easily possible, following his guidance, to read the words inscribed on the sheet of paper inside. So admirably defined were all the details that even the gum on the envelope and the edges of the sheet of paper inside the envelope could be distinguished.

“Any letter written with ink having a mineral basis can be radiographed,” added Craig. “Even when the sheet is folded in the usual way, it is possible by taking a radiograph stereoscopically, to distinguish the writing, every detail standing out in relief. Besides, it can be greatly magnified, which aids in deciphering it if it is indistinct or jumbled up. Some of it looks like mirror writing. Ah,” he added, “here’s something interesting!”

Together we managed to trace out the contents of several paragraphs, of which the significant parts were as follows:

I am expecting that my friend Señora Herreria will be in New York by the time you receive this, and should she call on you, I know you will accord her every courtesy. She has been in Mexico City for a few days, having just returned from Mitla, where she met Professor Northrop. It is rumored that Professor Northrop has succeeded in smuggling out of the country a very important stone bearing an inscription which, I understand, is of more than ordinary interest. I do not know anything definite about it, as Señora Herreria is very reticent on the matter, but depend on you to find out if possible and let me know of it.

According to the rumors and the statements of the señora, it seems that Northrop has taken an unfair advantage of the situation down in Oaxaca, and I suppose she and others who know about the inscription feel that it is really the possession of the government.

You will find that the señora is an accomplished antiquarian and scholar. Like many others down here just now, she has a high regard for the Japanese. As you know, there exists a natural sympathy between some Mexicans and Japanese, owing to what is believed to be a common origin of the two races.

In spite of the assertions of many to the contrary, there is little doubt left in the minds of students that the Indian races which have peopled Mexico were of Mongolian stock. Many words in some dialects are easily understood by Chinese immigrants. A secretary of the Japanese legation here was able recently to decipher old Mixtec inscriptions found in the ruins of Mitla.

Señora Herreria has been much interested in establishing the relationship and, I understand, is acquainted with a Japanese curio dealer in New York who recently visited Mexico for the same purpose. I believe that she wishes to collaborate with him on a monograph on the subject, which is expected to have a powerful effect on the public opinion both here and at Tokyo.

In regard to the inscription which Northrop has taken with him, I rely on you to keep me informed. There seems to be a great deal of mystery connected with it, and I am simply hazarding a guess as to its nature. If it should prove to be something which might interest either the Japanese or ourselves, you can see how important it may be, especially in view of the forthcoming mission of General Francisco to Tokyo.

Very sincerely yours,
DR. EMILIO SANCHEZ, Director.

“Bernardo is a Mexican,” I exclaimed, as Kennedy finished reading, “and there can be no doubt that the woman he mentioned was this Señora Herreria.”

Kennedy said nothing, but seemed to be weighing the various paragraphs in the letter.

“Still,” I observed, “so far, the only one against whom we have any direct suspicion in the case is the shaggy Russian, whoever he is.”

“A man whom Bernardo says looked like a Russian,” corrected Craig.

He was pacing the laboratory restlessly.

“This is becoming quite an international affair,” he remarked finally, pausing before me, his hat on. “Would you like to relax your mind by a little excursion among the curio shops of the city? I know something about Japanese curios—more, perhaps, than I do of Mexican. It may amuse us, even if it doesn’t help in solving the mystery. Meanwhile, I shall make arrangements for shadowing Bernardo. I want to know just how he acts after he reads that letter.”

He paused long enough to telephone his instructions to an uptown detective agency which could be depended on for such mere routine work, then joined me with the significant remark: “Blood is thicker than water, anyhow, Walter. Still, even if the Mexicans are influenced by sentiment, I hardly think that would account for the interest of our friends from across the water in the matter.”

I do not know how many of the large and small curio shops of the city we visited that afternoon. At another time, I should have enjoyed the visits immensely, for anyone seeking articles of beauty will find the antique shops of Fifth and Fourth Avenues and the side streets well worth visiting.

We came, at length, to one, a small, quaint, dusty rookery, down in a basement, entered almost directly from the street. It bore over the door a little gilt sign which read simply, “Sato’s.”

As we entered, I could not help being impressed by the wealth of articles in beautiful cloisonne enamel, in mother-of-pearl, lacquer, and champleve. There were beautiful little koros, or incense burners, vases, and teapots. There were enamels incrusted, translucent, and painted, works of the famous Namikawa, of Kyoto, and Namikawa, of Tokyo. Satsuma vases, splendid and rare examples of the potter’s art, crowded gorgeously embroidered screens depicting all sorts of brilliant scenes, among others the sacred Fujiyama rising in the stately distance. Sato himself greeted us with a ready smile and bow.

“I am just looking for a few things to add to my den,” explained Kennedy, adding, “nothing in particular, but merely whatever happens to strike my fancy.”

“Surely, then, you have come to the right shop,” greeted Sato. “If there is anything that interests you, I shall be glad to show it.”

“Thank you,” replied Craig. “Don’t let me trouble you with your other customers. I will call on you if I see anything.”

For several minutes, Craig and I busied ourselves looking about, and we did not have to feign interest, either.

“Often things are not as represented,” he whispered to me, after a while, “but a connoiseur can tell spurious goods. These are the real thing, mostly.”

“Not one in fifty can tell the difference,” put in the voice of Sato, at his elbow.

“Well, you see I happen to know,” Craig replied, not the least disconcerted. “You can’t always be too sure.”

A laugh and a shrug was Sato’s answer. “It’s well all are not so keen,” he said, with a frank acknowledgment that he was not above sharp practices.

I glanced now and then at the expressionless face of the curio dealer. Was it merely the natural blankness of his countenance that impressed me, or was there, in fact, something deep and dark hidden in it, something of “East is East and West is West” which I did not and could not understand? Craig was admiring the bronzes. He had paused before one, a square metal fire-screen of odd design, with the title on a card, “Japan Gazing at the World.”

It represented Japan as an eagle, with beak and talons of burnished gold, resting on a rocky island about which great waves dashed. The bird had an air of dignity and conscious pride in its strength, as it looked out at the world, a globe revolving in space.

“Do you suppose there is anything significant in that?” I asked, pointing to the continent of North America, also in gold and prominently in view.

“Ah, honorable sir,” answered Sato, before Kennedy could reply, “the artist intended by that to indicate Japan’s friendliness for America and America’s greatness.”

He was inscrutable. It seemed as if he were watching our every move, and yet it was done with a polite cordiality that could not give offense.

Behind some bronzes of the Japanese Hercules destroying the demons and other mythical heroes was a large alcove, or tokonoma, decorated with peacock, stork, and crane panels. Carvings and lacquer added to the beauty of it. A miniature chrysanthemum garden heightened the illusion. Carved hinoki wood framed the panels, and the roof was supported by columns in the old Japanese style, the whole being a compromise between the very simple and quiet and the polychromatic. The dark woods, the lanterns, the floor tiles of dark red, and the cushions of rich gold and yellow were most alluring. It had the genuine fascination of the Orient.

“Will the gentlemen drink a little sake?” Sato asked politely.

Craig thanked him and said that we would.

“Otaka!” Sato called.

A peculiar, almost white-skinned attendant answered, and a moment later produced four cups and poured out the rice brandy, taking his own quietly, apart from us. I watched him drink, curiously. He took the cup; then, with a long piece of carved wood, he dipped into the sake, shaking a few drops on the floor to the four quarters. Finally, with a deft sweep, he lifted his heavy mustache with the piece of wood and drank off the draft almost without taking breath.

He was a peculiar man of middle height, with a shock of dark, tough, woolly hair, well formed and not bad-looking, with a robust general physique, as if his ancestors had been meat eaters. His forehead was narrow and sloped backward; the cheekbones were prominent; nose hooked, broad and wide, with strong nostrils; mouth large, with thick lips, and not very prominent chin. His eyes were perhaps the most noticeable feature. They were dark gray, almost like those of a European.

As Otaka withdrew with the empty cups, we rose to continue our inspection of the wonders of the shop. There were ivories of all descriptions. Here was a two-handled sword, with a very large ivory handle, a weirdly carved scabbard, and wonderful steel blade. By the expression of Craig’s face, Sato knew that he had made a sale.

Craig had been rummaging among some warlike instruments which Sato, with the instincts of a true salesman, was now displaying, and had picked up a bow. It was short, very strong, and made of pine wood. He held it horizontally and twanged the string. I looked up in time to catch a pleased expression on the face of Otaka.

“Most people would have held it the other way,” commented Sato.

Craig said nothing, but was examining an arrow, almost twenty inches long and thick, made of cane, with a point of metal very sharp but badly fastened. He fingered the deep blood groove in the scooplike head of the arrow and looked at it carefully.

“I’ll take that,” he said, “only I wish it were one with the regular reddish-brown lump in it.”

“Oh, but, honorable sir,” apologized Sato, “the Japanese law prohibits that, now. There are few of those, and they are very valuable.”

“I suppose so,” agreed Craig. “This will do, though. You have a wonderful shop here, Sato. Some time, when I feel richer, I mean to come in again. No, thank you, you need not send them; I’ll carry them.”

We bowed ourselves out, promising to come again when Sato received a new consignment from the Orient which he was expecting.

“That other Jap is a peculiar fellow,” I observed, as we walked along uptown again.

“He isn’t a Jap,” remarked Craig. “He is an Ainu, one of the aborigines who have been driven northward into the island of Yezo.”

“An Ainu?” I repeated.

“Yes. Generally thought, now, to be a white race and nearer of kin to Europeans than Asiatics. The Japanese have pushed them northward and are now trying to civilize them. They are a dirty, hairy race, but when they are brought under civilizing influences they adapt themselves to their environment and make very good servants. Still, they are on about the lowest scale of humanity.”

“I thought Otaka was very mild,” I commented.

“They are a most inoffensive and peaceable people usually,” he answered, “good-natured and amenable to authority. But they become dangerous when driven to despair by cruel treatment. The Japanese government is very considerate of them—but not all Japanese are.”

CHAPTER XII
THE ARROW POISON

Far into the night Craig was engaged in some very delicate and minute microscopic work in the laboratory.

We were about to leave when there was a gentle tap on the door. Kennedy opened it and admitted a young man, the operative of the detective agency who had been shadowing Bernardo. His report was very brief, but, to me at least, significant. Bernardo, on his return to the museum, had evidently read the letter, which had agitated him very much, for a few moments later he hurriedly left and went downtown to the Prince Henry Hotel. The operative had casually edged up to the desk and overheard whom he asked for. It was Señora Herreria. Once again, later in the evening, he had asked for her, but she was still out.

It was quite early the next morning, when Kennedy had resumed his careful microscopic work, that the telephone bell rang, and he answered it mechanically. But a moment later a look of intense surprise crossed his face.

“It was from Doctor Leslie,” he announced, hanging up the receiver quickly. “He has a most peculiar case which he wants me to see—a woman.”

Kennedy called a cab, and, at a furious pace, we dashed across the city and down to the Metropolitan Hospital, where Doctor Leslie was waiting. He met us eagerly and conducted us to a little room where, lying motionless on a bed, was a woman.

She was a striking-looking woman, dark of hair and skin, and in life she must have been sensuously attractive. But now her face was drawn and contorted—with the same ghastly look that had been on the face of Northrop.

“She died in a cab,” explained Doctor Leslie, “before they could get her to the hospital. At first they suspected the cab driver. But he seems to have proved his innocence. He picked her up last night on Fifth Avenue, reeling—thought she was intoxicated. And, in fact, he seems to have been right. Our tests have shown a great deal of alcohol present, but nothing like enough to have had such a serious effect.”

“She told nothing of herself?” asked Kennedy.

“No; she was pretty far gone when the cabby answered her signal. All he could get out of her was a word that sounded like ‘Curio-curio.’ He says she seemed to complain of something about her mouth and head. Her face was drawn and shrunken; her hands were cold and clammy, and then convulsions came on. He called an ambulance, but she was past saving when it arrived. The numbness seemed to have extended over all her body; swallowing was impossible; there was entire loss of her voice as well as sight, and death took place by syncope.”

“Have you any clue to the cause of her death?” asked Craig.

“Well, it might have been some trouble with her heart, I suppose,” remarked Doctor Leslie tentatively.

“Oh, she looks strong that way. No, hardly anything organic.”

“Well, then I thought she looked like a Mexican,” went on Doctor Leslie. “It might be some new tropical disease. I confess I don’t know. The fact is,” he added, lowering his voice, “I had my own theory about it until a few moments ago. That was why I called you.”

“What do you mean?” asked Craig, evidently bent on testing his own theory by the other’s ignorance.

Doctor Leslie made no answer immediately, but raised the sheet which covered her body and disclosed, in the fleshy part of the upper arm, a curious little red swollen mark with a couple of drops of darkened blood.

“I thought at first,” he added, “that we had at last a genuine ‘poisoned needle’ case. You see, that looked like it. But I have made all the tests for curare and strychnin without results.”

At the mere suggestion, a procession of hypodermic-needle and white-slavery stories flashed before me.

“But,” objected Kennedy, “clearly this was not a case of kidnaping. It is a case of murder. Have you tested for the ordinary poisons?”

Doctor Leslie shook his head. “There was no poison,” he said, “absolutely none that any of our tests could discover.”

Kennedy bent over and squeezed out a few drops of liquid from the wound on a microscope slide, and covered them.

“You have not identified her yet,” he added, looking up. “I think you will find, Leslie, that there is a Señora Herreria registered at the Prince Henry who is missing, and that this woman will agree with the description of her. Anyhow, I wish you would look it up and let me know.”

Half an hour later, Kennedy was preparing to continue his studies with the microscope when Doctor Bernardo entered. He seemed most solicitous to know what progress was being made on the case, and, although Kennedy did not tell much, still he did not discourage conversation on the subject.

When we came in the night before, Craig had unwrapped and tossed down the Japanese sword and the Ainu bow and arrow on a table, and it was not long before they attracted Bernardo’s attention.

“I see you are a collector yourself,” he ventured, picking them up.

“Yes,” answered Craig, offhand; “I picked them up yesterday at Sato’s. You know the place?”

“Oh, yes, I know Sato,” answered the curator, seemingly without the slightest hesitation. “He has been in Mexico—is quite a student.”

“And the other man, Otaka?”

“Other man—Otaka? You mean his wife?”

I saw Kennedy check a motion of surprise and came to the rescue with the natural question: “His wife—with a beard and mustache?”

It was Bernardo’s turn to be surprised. He looked at me a moment, then saw that I meant it, and suddenly his face lighted up.

“Oh,” he exclaimed, “that must have been on account of the immigration laws or something of the sort. Otaka is his wife. The Ainus are much sought after by the Japanese as wives. The women, you know, have a custom of tattooing mustaches on themselves. It is hideous, but they think it is beautiful.”

“I know,” I pursued, watching Kennedy’s interest in our conversation, “but this was not tattooed.”

“Well, then, it must have been false,” insisted Bernardo.

The curator chatted a few moments, during which I expected Kennedy to lead the conversation around to Señora Herreria. But he did not, evidently fearing to show his hand.

“What did you make of it?” I asked, when he had gone. “Is he trying to hide something?”

“I think he has simplified the case,” remarked Craig, leaning back, his hands behind his head, gazing up at the ceiling. “Hello, here’s Leslie! What did you find, Doctor?” The coroner had entered with a look of awe on his face, as if Kennedy had directed him by some sort of necromancy.

“It was Señora Herreria!” he exclaimed. “She has been missing from the hotel ever since late yesterday afternoon. What do you think of it?”

“I think,” replied Kennedy, speaking slowly and deliberately, “that it is very much like the Northrop case. You haven’t taken that up yet?”

“Only superficially. What do you make of it?” asked the coroner.

“I had an idea that it might be aconitin poisoning,” he said.

Leslie glanced at him keenly for a moment. “Then you’ll never prove anything in the laboratory,” he said.

“There are more ways of catching a criminal, Leslie,” put in Craig, “than are set down in the medico-legal text-books. I shall depend on you and Jameson to gather together a rather cosmopolitan crowd here to-night.”

He said it with a quiet confidence which I could not gainsay, although I did not understand. However, mostly with the official aid of Doctor Leslie, I followed out his instructions, and it was indeed a strange party that assembled that night. There were Doctor Bernardo; Sato, the curio dealer; Otaka, the Ainu, and ourselves. Mrs. Northrop, of course, could not come.

“Mexico,” began Craig, after he had said a few words explaining why he had brought us together, “is full of historical treasure. To all intents and purposes, the government says, ‘Come and dig.’ But when there are finds, then the government swoops down on them for its own national museum. The finder scarcely gets a chance to export them. However, now seemed to be the time to Professor Northrop to smuggle his finds out of the country.

“But evidently it could not be done without exciting all kinds of rumors and suspicions. Stories seem to have spread far and fast about what he had discovered. He realized the unsettled condition of the country—perhaps wanted to confirm his reading of a certain inscription by consultation with one scholar whom he thought he could trust. At any rate, he came home.”

Kennedy paused, making use of the silence for emphasis. “You have all read of the wealth that Cortez found in Mexico. Where are the gold and silver of the conquistadores? Gone to the melting pot, centuries ago. But is there none left? The Indians believe so. There are persons who would stop at nothing—even at murder of American professors, murder of their own comrades, to get at the secret.”

He laid his hand almost lovingly on his powerful little microscope as he resumed on another line of evidence.

“And while we are on the subject of murders, two very similar deaths have occurred,” he went on. “It is of no use to try to gloss them over. Frankly, I suspected that they might have been caused by aconite poisoning. But, in the case of such poisoning, not only is the lethal dose very small but our chemical methods of detection are nil. The dose of the active principle, aconitin nitrate, is about one six-hundredth of a grain. There are no color tests, no reactions, as in the case of the other organic poisons.”

I wondered what he was driving at. Was there, indeed, no test? Had the murderer used the safest of poisons—one that left no clue? I looked covertly at Sato’s face. It was impassive. Doctor Bernardo was visibly uneasy as Kennedy proceeded. Cool enough up to the time of the mention of the treasure, I fancied, now, that he was growing more and more nervous.

Craig laid down on the table the reed stick with the little darkened cylinder on the end.

“That,” he said, “is a little article which I picked up beneath Northrop’s window yesterday. It is a piece of anno-noki, or bushi.” I fancied I saw just a glint of satisfaction in Otaka’s eyes.

“Like many barbarians,” continued Craig, “the Ainus from time immemorial have prepared virulent poisons with which they charged their weapons of the chase and warfare. The formulas for the preparations, as in the case of other arrow poisons of other tribes, are known only to certain members, and the secret is passed down from generation to generation as an heirloom, as it were. But in this case it is no longer a secret. It has now been proved that the active principle of this poison is aconite.”

“If that is the case,” broke in Doctor Leslie, “it is hopeless to connect anyone directly in that way with these murders. There is no test for aconitin.”

I thought Sato’s face was more composed and impassive than ever. Doctor Bernardo, however, was plainly excited.

“What—no test—none?” asked Kennedy, leaning forward eagerly. Then, as if he could restrain the answer to his own question no longer, he shot out: “How about the new starch test just discovered by Professor Reichert, of the University of Pennsylvania? Doubtless you never dreamed that starch may be a means of detecting the nature of a poison in obscure cases in criminology, especially in cases where the quantity of poison necessary to cause death is so minute that no trace of it can be found in the blood.

“The starch method is a new and extremely inviting subject to me. The peculiarities of the starch of any plant are quite as distinctive of the plant as are those of the hemoglobin crystals in the blood of an animal. I have analyzed the evidence of my microscope in this case thoroughly. When the arrow poison is introduced subcutaneously—say, by a person shooting a poisoned dart, which he afterward removes in order to destroy the evidence—the lethal constituents are rapidly absorbed.

“But the starch remains in the wound. It can be recovered and studied microscopically and can be definitely recognized. Doctor Reichert has published a study of twelve hundred such starches from all sorts of plants. In this case, it not only proves to be aconitin but the starch granules themselves can be recognized. They came from this piece of arrow poison.”

Every eye was fixed on him now.

“Besides,” he rapped out, “in the soft soil beneath the window of Professor Northrop’s room, I found footprints. I have only to compare the impressions I took there and those of the people in this room, to prove that, while the real murderer stood guard below the window, he sent some one more nimble up the rain pipe to shoot the poisoned dart at Professor Northrop, and, later, to let down a rope by which he, the instigator, could gain the room, remove the dart, and obtain the key to the treasure he sought.”

Kennedy was looking straight at Professor Bernardo.

“A friend of mine in Mexico has written me about an inscription,” he burst out. “I received the letter only to-day. As nearly as I can gather, there was an impression that some of Northrop’s stuff would be valuable in proving the alleged kinship between Mexico and Japan, perhaps to arouse hatred of the United States.”

“Yes—that is all very well,” insisted Kennedy. “But how about the treasure?”

“Treasure?” repeated Bernardo, looking from one of us to another.

“Yes,” pursued Craig relentlessly, “the treasure. You are an expert in reading the hieroglyphics. By your own statement, you and Northrop had been going over the stuff he had sent up. You know it.”

Bernardo gave a quick glance from Kennedy to me. Evidently he saw that the secret was out.

“Yes,” he said huskily, in a low tone, “Northrop and I were to follow the directions after we had plotted them out and were to share it together on the next expedition, which I could direct as a Mexican without so much suspicion. I should still have shared it with his widow if this unfortunate affair had not exposed the secret.”

Bernardo had risen earnestly.

“Kennedy,” he cried, “before God, if you will get back that stone and keep the secret from going further than this room, I will prove what I have said by dividing the Mixtec treasure with Mrs. Northrop and making her one of the richest widows in the country!”

“That is what I wanted to be sure of,” nodded Craig. “Bernardo, Señora Herreria, of whom your friend wrote to you from Mexico, has been murdered in the same way that Professor Northrop was. Otaka was sent by her husband to murder Northrop, in order that they might obtain the so-called ‘Pillar of Death’ and the key to the treasure. Then, when the señora was no doubt under the influence of sake in the pretty little Oriental bower at the curio shop, a quick jab, and Otaka had removed one who shared the secret with them.”

He had turned and faced the pair.

“Sato,” he added, “you played on the patriotism of the señora until you wormed from her the treasure secret. Evidently rumors of it had spread from Mexican Indians to Japanese visitors. And then, Otaka, all jealousy over one whom she, no doubt, justly considered a rival, completed your work by sending her forth to die, unknown, on the street. Walter, ring up First Deputy O’Connor. The stone is hidden somewhere in the curio shop. We can find it without Sato’s help. The quicker such a criminal is lodged safely in jail, the better for humanity.”

Sato was on his feet, advancing cautiously toward Craig. I knew the dangers, now, of anno-noki, as well as the wonders of jujutsu, and, with a leap, I bounded past Bernardo and between Sato and Kennedy.

How it happened, I don’t know, but, an instant later, I was sprawling.

Before I could recover myself, before even Craig had a chance to pull the hair-trigger of his automatic, Sato had seized the Ainu arrow poison from the table, had bitten the little cylinder in half, and had crammed the other half into the mouth of Otaka.

CHAPTER XIII
THE RADIUM ROBBER

Kennedy simply reached for the telephone and called an ambulance. But it was purely perfunctory. Dr. Leslie himself was the only official who could handle Sato’s case now.

We had planned a little vacation for ourselves, but the planning came to naught. The next night we spent on a sleeper. That in itself is work to me.

It all came about through a hurried message from Murray Denison, president of the Federal Radium Corporation. Nothing would do but that he should take both Kennedy and myself with him post-haste to Pittsburgh at the first news of what had immediately been called “the great radium robbery.”

Of course the newspapers were full of it. The very novelty of an ultra-modern cracksman going off with something worth upward of a couple of hundred thousand dollars—and all contained in a few platinum tubes which could be tucked away in a vest pocket—had something about it powerfully appealing to the imagination.

“Most ingenious, but, you see, the trouble with that safe is that it was built to keep radium in—not cracksmen out,” remarked Kennedy, when Denison had rushed us from the train to take a look at the little safe in the works of the Corporation.

“Breaking into such a safe as this,” added Kennedy, after a cursory examination, “is simple enough, after all.”

It was, however, a remarkably ingenious contrivance, about three feet in height and of a weight of perhaps a ton and a half, and all to house something weighing only a few grains.

“But,” Denison hastened to explain, “we had to protect the radium not only against burglars, but, so to speak, against itself. Radium emanations pass through steel and experiments have shown that the best metal to contain them is lead. So, the difficulty was solved by making a steel outer case enclosing an inside leaden shell three inches thick.”

Kennedy had been toying thoughtfully with the door.

“Then the door, too, had to be contrived so as to prevent any escape of the emanations through joints. It is lathe turned and circular, a ‘dead fit.’ By means of a special contrivance any slight looseness caused by wear and tear of closing can be adjusted. And another feature. That is the appliance for preventing the loss of emanation when the door is opened. Two valves have been inserted into the door and before it is opened tubes with mercury are passed through which collect and store the emanation.”

“All very nice for the radium,” remarked Craig cheerfully. “But the fellow had only to use an electric drill and the gram or more of radium was his.”

“I know that—now,” ruefully persisted Denison. “But the safe was designed for us specially. The fellow got into it and got away, as far as I can see, without leaving a clue.”

“Except one, of course,” interrupted Kennedy quickly.

Denison looked at him a moment keenly, then nodded and said, “Yes—you are right. You mean one which he must bear on himself?”

“Exactly. You can’t carry a gram or more of radium bromide long with impunity. The man to look for is one who in a few days will have somewhere on his body a radium burn which will take months to heal. The very thing he stole is a veritable Frankenstein’s monster bent on the destruction of the thief himself!”

Kennedy had meanwhile picked up one of the Corporation’s circulars lying on a desk. He ran his eye down the list of names.

“So, Hartley Haughton, the broker, is one of your stockholders,” mused Kennedy.

“Not only one but the one,” replied Denison with obvious pride.

Haughton was a young man who had come recently into his fortune, and, while no one believed it to be large, he had cut quite a figure in Wall Street.

“You know, I suppose,” added Denison, “that he is engaged to Felicie Woods, the daughter of Mrs. Courtney Woods?”

Kennedy did not, but said nothing.

“A most delightful little girl,” continued Denison thoughtfully. “I have known Mrs. Woods for some time. She wanted to invest, but I told her frankly that this is, after all, a speculation. We may not be able to swing so big a proposition, but, if not, no one can say we have taken a dollar of money from widows and orphans.”

“I should like to see the works,” nodded Kennedy approvingly.

“By all means.”

The plant was a row of long low buildings of brick on the outskirts of the city, once devoted to the making of vanadium steel. The ore, as Denison explained, was brought to Pittsburgh because he had found here already a factory which could readily be turned into a plant for the extraction of radium. Huge baths and vats and crucibles for the various acids and alkalis and other processes used in treating the ore stood at various points.

“This must be like extracting gold from sea water,” remarked Kennedy jocosely, impressed by the size of the plant as compared to the product.

“Except that after we get through we have something infinitely more precious than gold,” replied Denison, “something which warrants the trouble and outlay. Yes, the fact is that the percentage of radium in all such ores is even less than of gold in sea water.”

“Everything seems to be most carefully guarded,” remarked Kennedy as we concluded our tour of the well-appointed works.

He had gone over everything in silence, and now at last we had returned to the safe.

“Yes,” he repeated slowly, as if confirming his original impression, “such an amount of radium as was stolen wouldn’t occasion immediate discomfort to the thief, I suppose, but later no infernal machine could be more dangerous to him.”

THE CRAIG KENNEDY SERIES

The War Terror

by Arthur B. Reeve

Contents

INTRODUCTION

CHAPTER ITHE WAR TERROR

CHAPTER IITHE ELECTRO-MAGNETIC GUN

CHAPTER IIITHE MURDER SYNDICATE

CHAPTER IVTHE AIR PIRATE

CHAPTER VTHE ULTRA-VIOLET RAY

CHAPTER VITHE TRIPLE MIRROR

CHAPTER VIITHE WIRELESS WIRETAPPERS

CHAPTER VIIITHE HOUSEBOAT MYSTERY

CHAPTER IXTHE RADIO DETECTIVE

CHAPTER XTHE CURIO SHOP

CHAPTER XITHE “PILLAR OF DEATH”

CHAPTER XIITHE ARROW POISON

CHAPTER XIIITHE RADIUM ROBBER