The Project Gutenberg eBook, The Boy Allies with the Terror of the Seas, by Clair W. (Clair Wallace) Hayes

“WELL, SHE’S GONE,” SAID JACK, QUIETLY.

The Boy Allies

With the Terror of the Seas

OR

The Last Shot of Submarine D-16

By Ensign ROBERT L. DRAKE

AUTHOR OF

“The Boy Allies On the North Sea Patrol”

“The Boy Allies Under Two Flags”

“The Boy Allies With the Flying Squadron”

Copyright, 1915

By A. L. Burt Company

THE BOY ALLIES WITH THE TERROR OF THE SEAS

Contents

THE BOY ALLIES WITH THE TERROR OF THE SEAS.

CHAPTER I.
UNDER THE SEA.

“One!”

The speaker was Jack Templeton, an English youth and first officer of the British submarine D-16, Lord Hastings, commander.

Frank Chadwick, an American lad about the same age as Jack, the second officer of the under-sea fighter, laid his hand upon his friend’s arm.

“Let me take a look,” he said.

Jack relinquished to his chum his place at the periscope, and the latter peered into the instrument long and earnestly.

Into the periscope—which protruded slightly above the surface of the water while the submarine was still submerged—came the vision of a sinking warship, and the sight, enlarged by powerful binoculars, was apparent to Frank’s eyes.

“She’s done for, all right,” he said quietly, turning away at length. “Pretty good shooting, I should say.”

“One torpedo only,” replied Jack briefly.

“You may give the signal to rise, Mr. Templeton,” said a third voice, and Lord Hastings, commander of the submarine, stood before them.

Jack turned away in response to this command.

Another moment and the pumps were at work, forcing the water from the tanks. Gradually the submarine began to rise, and at last rode quietly upon the surface of the North Sea.

Followed by Jack and Frank, Lord Hastings led the way up through the little conning tower, opened now that the submarine was above water, and from there to the bridge, only a few feet above the surface of the sea. Here all turned their eyes toward the east, where, less than half a mile away, a German ship of war was slowly sinking by the head.

“A good shot, Mr. Templeton,” said Lord Hastings, turning to Jack.

“Pretty fair, sir,” was the latter’s modest reply, for he had launched the torpedo with his own hand.

Aboard the sinking German vessel all was confusion. Men rushed hither and thither in wild excitement. Officers shouted hoarse commands. Men scrambled wildly about and jumped madly for the life boats as they were launched. So great was the panic that two of the small boats were overturned and the men thrown into the sea.

“They’ll be drowned!” exclaimed Frank. He turned to Lord Hastings. “Cannot we rescue them, sir?”

“It is impossible,” was the quiet response. “We have no room for them. We are carrying a full crew, as you know, and have no room for another man.”

“But it is terrible to let them drown,” protested Frank.

“True,” replied his commander, “and yet think how some of our merchant vessels have been sent to the bottom without warning and their crews to a watery grave, noncombatants though they were. It is retribution; no less.”

Frank was silent, but he stood watching the struggling German sailors with an anxious eye.

Now the officers aboard the sinking vessel had succeeded in gaining some semblance of order from the confusion that had reigned a few moments before, and the enemy was going about the work of launching the boats more coolly and successfully.

At last all the boats and the crew had left the ship—all but one man, who still stood calmly upon the bridge. This was the commander, who, rather than leave his ship, was preparing to go down with her. In vain did his officers from the boats call upon him to jump. To all their calls he turned a deaf ear, and stood calmly at his post, with folded arms.

Now the sinking vessel began to settle more swiftly. Suddenly she seemed to leap clear of the water, there came a thundering roar, and then, seeming to despair of her efforts to keep afloat, she dived, in another moment she disappeared and the waters of the North Sea closed with an angry swirl over the mighty German warship and her gallant commander.

“Well, she’s gone,” said Jack quietly.

“Then we may as well go also,” declared Lord Hastings. “Shape your course due west, Mr. Templeton.”

“Very good, sir,” replied Jack, saluting, and he disappeared below.

Lord Hastings and Frank continued to peer at the flotilla of German small boats, which, at a command from the officer in charge, had shipped their oars and were pulling toward the east with lusty strokes.

“I hope they make land safely, or are picked up,” said Frank.

“So do I,” replied his commander. “Come, we shall go below.”

The D-16 again on her way, Frank betook himself to his own quarters, which he and Jack shared together. Here he was surprised to see the latter cutting a notch on the side of the highly polished small table in the center of the cabin.

“What are you doing there?” he asked in surprise. “What are you cutting up that table for?”

“Well,” said Jack, “in reading some of your American literature, I learned that every time one of your wild westerners killed a man he cut a notch on his gun. I’m following along the same lines, only I intend to cut a notch on this table every time we sink one of the enemy.”

“Quite an idea, that,” said Frank. “But when you say you read that stuff in American literature, you are wrong. I won’t deny that you have read it, but I’d call it American fiction, not literature.”

“Never mind,” said Jack, “it’ll answer my purpose, whatever you call it.”

“Guess I’ll turn in for a couple of hours,” said Frank. “I’m feeling rather tired.”

“Help yourself,” replied his friend. “I want a few words with Lord Hastings.”

He left the cabin, while Frank, kicking off his shoes and removing his coat, threw himself down on his bed, and in a few moments was fast asleep. As he is taking much needed repose, we will take the time to introduce these two lads more fully.

Jack Templeton, the son of an Englishman, had spent the better part of his life in a little village on the north coast of Africa. His father, who owned a small store, had been his only instructor, but in spite of this the lad had been given a first-class education. He was well read in literature and history, could pass muster on almost any other subject and was well posted on current events.

Jack’s father had been taken suddenly ill and after a protracted sickness died. Jack took charge of the store. One day a ship put into the harbor and several sailors landed, went to the store and procured provisions. In Jack’s absence, they departed without making payment.

Jack returned a little while later, and when he learned what had occurred, he put off in a small boat after the ship, which he reached before she could get under way.

Now Jack, though young in years, was a stalwart lad. He stood above six feet, and was built proportionately. The sailors laughed at him when he demanded payment and a struggle followed. By exerting his powerful strength and some resourcefulness, Jack succeeded in overcoming the crew.

It was then that he learned there were two prisoners aboard the ship. These he released. They proved to be Frank Chadwick and a British secret diplomatic agent.

Frank, who had been in Germany when the great European war broke out, had become separated from his father after getting over the border into Italy. In Naples one night he had gone to the aid of a sailor on the water front and saved him from injury at the hands of three others.

The sailor whom Frank had rescued showed a queer sense of gratitude by having him shanghaied aboard a small schooner. Here, under the stern rule of an American skipper, he had become one of the crew. The crew mutinied, killed the captain, and, binding Frank securely, threw him below with the other prisoner, the diplomatic agent.

Jack’s unexpected appearance upon the scene was indeed a welcome sight to both. Upon learning the nature of the work upon which the secret agent was bound, the two lads had volunteered to help him out. This offer was accepted, and thus both found themselves principal figures in a diplomatic coup that broke up the Triple Alliance and took the support of Italy away from Germany and Austria.

It was while with the secret agent that they had met Lord Hastings, and it was through the good offices of the latter that they finally found themselves attached to the British fleet as midshipmen. Lord Hastings had taken an instant liking to the lads and had them attached to his ship. Later they had been commissioned lieutenants.

Jack and Frank had seen considerable fighting. It was through their strategy that the British had won their first sea victory, off the coast of Heligoland, when four of Germany’s most powerful sea fighters had been sent to the bottom. They had saved the British fleet from possible annihilation by being fortunate to discover a spy.

The two lads, since the war began, had seen service in many waters. They had been on patrol duty off the west coast of Africa; they had served under the French flag when, under the tricolor, they had delivered a severe blow to the Austrian fleet in the Adriatic; they had trailed the German cruiser Emden, nicknamed the “terror of the sea,” through the Indian ocean, and had been present when she was finally sunk by the Australian cruiser Sydney; they had taken part in sinking the German fleet in the South Atlantic, off the Falkland islands; they had been aboard a British submarine that sank three Turkish cruisers in the Persian Gulf; they had seen the capture of the German fortress of Tsing-Tau, in China, by allied British and Japanese troops, and finally they had been instrumental, while in London, of exposing a plot that would have been a severe blow to Great Britain, and of capturing a second German spy and a British traitor, who stood high in the regard of Winston Spencer Churchill, first lord of the Admiralty.

Three times the ships to which they were attached had been sunk, and they had had many narrow escapes. Once Lord Hastings had gone down with their vessel, and the lads had believed him drowned, but he escaped and they encountered him weeks later.

When their last craft had been sunk, upon the boys’ suggestion, Lord Hastings had requested command of a submarine, and when they had once again set forth, it was in the D-16.

And as the D-16 was something absolutely new in the way of submarines, a few words concerning it are necessary here.

CHAPTER II.
THE D-16.

The British submarine D-16 was, at this time at any rate, the only under-the-water vessel that could remain under the sea indefinitely. The one real weakness of beneath-the-sea fighters had always been their inability to remain long under water, and for this reason they could operate only within a certain radius of their base.

In discovering that there was a means by which a submarine could remain indefinitely under water, Sir John H—— had overcome this difficulty. The new invention had been tried on the D-16, and it had worked.

According to Sir John, a submarine in order to remain submerged indefinitely, must be able to extract air from the water, as does a fish, for it is air that is needed most under water. Up to the time of Sir John H——’s discovery this had never been accomplished.

Reasoning that it must be a peculiarity about the gills of a fish that permitted it to extract air from the water, Sir John had experimented along this line, and his experiments finally terminated successfully. When the D-16 had proved the practicability of Sir John’s theory, the vessel had immediately been put into commission, and the construction of others begun.

The secret of the D-16 was known to only a trusted few besides the crew of the vessel—the King, Winston Churchill, and David Lloyd George, Chancellor of the Exchequer. Besides her ability to remain submerged, D-16 was also many knots faster than any other submarine.

From a naval viewpoint, perhaps, the war up to this time had not progressed as favorably as had been expected. While the allied forces on the continent had been hemming in the Germans and their allies, driving them back from beneath the very walls of Paris, back across the Marne and across the Aisne, and while the legions of the Czar had been attempting to force a passage of the Carpathian mountains for an invasion of Hungary and Austria, and making determined assault within the borders of East Prussia, the British, French and Russian fleets had been practically inactive.

True, there had been several important naval battles, but none which could be called decisive, although whatever advantage there was was with the British.

The French, with the Austrian fleet cooped up in their base in the Adriatic, had little to do but to see that the Austrians were not allowed to escape. The Russian fleet had had one or two brushes with the Turks, but these were unimportant.

In the North Sea England was having more difficulty. German submarines, from their base at Ostend, had made several successful raids into Dover harbor, on the British coast; three unfortified towns on the coast had been razed by German shells and German aeroplanes had been seen flying about in the vicinity of London.

Huge Zeppelin balloons, upon which, England believed, the German Emperor planned to risk all should other means fail, had been seen over the British Isles, but had been driven off. One had been sunk. After this, England, ever fearful of an air raid, took heart, and agreed with the nobleman who said that a raid by air was not feasible.

Besides the ships of war that had been sunk by the Germans, British merchant vessels had also been sent to the bottom by the enemy’s submarines.

But the main German fleet was cooped up in Heligoland and in the Kiel canal by the British blockade, which, in itself, was proof positive of Great Britain’s naval supremacy. The Kaiser had no mind to give open battle to England on the sea.

This was the situation, then, when submarine D-16 set forth from London, to do, with her new power, what damage she could to the enemy’s fleet.

One day, while the lads had been looking over the vessel, as she lay in drydock, they had seen a man run furtively from the place as they approached; but they were unable to catch him. A second time they had seen him, though not close enough to identify him.

Although both had thought considerably of the matter, neither had mentioned it to the other, and it had been allowed to drop. Nor had they come upon the man again before they put to sea.

The sinking of the German vessel related in the first chapter had been the first venture of the D-16, and now the vessel was heading toward the coast of England again, having gone as far toward the strong fortress of Heligoland as Lord Hastings had deemed advisable at that time.

All day the little vessel continued on her way, traveling upon the surface, for there was now no need to submerge. She went very slowly, and night found her not many miles from the scene of her first encounter.

A sharp lookout was kept for some sign of an enemy, but there was none.

With the coming of the first light of day, Jack and Frank ascended the bridge together, and turned their eyes toward the west. A faint cloud of smoke on the horizon gave evidence of a ship of some sort.

“Probably a British vessel,” said Jack.

“Can’t tell,” returned Frank. “A German cruiser may have succeeded in running the blockade and getting in behind.”

“That’s true, too,” Jack agreed. “It’s a mystery to me how they do it. England is supposed to have them safely bottled up. It’s beyond me how they get out.”

“It’s beyond me, too. Of course, it’s easy enough for the submarine; but you’d think we’d be bound to spot a big cruiser.”

“Something will have to be done, sooner or later. What’s the use of a blockade if it doesn’t blockade?”

“Well,” said Frank dryly, “I have no doubt that if you have a plan, the admiralty would be glad to know it.”

“I haven’t any plan; but England will have to do something. That’s certain.”

“There is no question about that. Hello!”

“What’s up?” asked Jack, looking at his friend in some surprise.

For answer Frank pointed toward the east. Jack peered intently into the distance and also uttered an exclamation of surprise.

“Germans?” he asked.

“Must be,” replied Frank briefly.

He glanced ahead again. Then turned to his friend with an exclamation of satisfaction.

“If they are,” he said, “they’ll get more than they bargained for this time.”

For what his eyes had made out, through his glass, was the outline of five large battle cruisers, convoyed by a flotilla of torpedo boats.

“British?” asked Jack eagerly.

“Look like it,” replied Frank, “but I can’t tell for sure.”

It was plain to both lads that neither fleet had made out the presence of the other, and both—the one from the West and the one from the East—were steaming directly toward the little submarine, which lay squarely between them, though out of sight, because she sat so low in the water.

“Call Lord Hastings,” said Jack, and Frank hastened to obey.

A moment later the commander of the D-16 appeared on the bridge. He took in the situation at a glance.

“The fleet to the east is German,” he said, after a careful scrutiny through his glass, “and the other must be the British fleet commanded by Admiral Beatty.”

“Then there will be a fight,” said Frank.

“There will be unless the Germans perceive our ships soon enough to give them a chance to escape,” returned Lord Hastings. “Another hour undiscovered, however, and we’ll get them sure, for if I am not mistaken, the leading British ships are the Lion and the Tiger—the fastest cruisers afloat today. Also their guns are greatly superior to those of the enemy.”

“But what are we going to do?” asked Frank, somewhat impatiently. “We are not going to stand by and look on, are we?”

Lord Hastings smiled.

“Don’t you worry,” he said quietly. “We’ll take our part, whatever it may be. We’ll go below now.”

The three descended. The conning tower and bridge were closed behind them, and soon the tanks were opened. The D-16 submerged until the top of her periscope barely protruded above the edge of the water.

Lord Hastings, Frank and Jack took turns watching the approach of the two fleets, now that they were in range of the periscope; and it was while the latter was at the instrument that sudden signs of commotion became noticeable on the German vessels. At the same instant Jack perceived that the British ships had increased their stride, and were making directly for the Germans.

“They have sighted each other, sir,” he cried, turning to Lord Hastings in great excitement.

Lord Hastings sprang to the periscope.

“And the Germans are turning to run,” he said, after a quick glance.

It was true. The German commander, realizing that he was probably no match for the powerful British squadron, had no mind to give battle when the odds were as nearly even as they were now. Evidently he had more confidence in the power of his enemy than he had in his own. Therefore, immediately the British fleet was sighted, he gave the command to come about and make for the protection of the mined area about Heligoland at full speed.

But the time lost in coming about was to prove a severe blow to the Germans. The British fleet, led by the Tiger, Admiral Beatty’s flagship, had sighted its prey, and was making after it at full speed.

“Guess we might as well take a hand in this,” remarked Lord Hastings coolly. “Submerge another five fathoms, Mr. Templeton.”

More water was let into the tanks and the D-16 dropped rapidly lower into the sea.

“Full speed ahead, Mr. Templeton,” came the next command.

The D-16 seemed to leap forward like a live thing, as she dashed in pursuit of the fleeing German fleet.

“More notches for the table, I guess,” said Frank to Jack.

“We’ll see,” was the latter’s reply. “I hope so.”

CHAPTER III.
THE ENGAGEMENT.

Meanwhile the British fleet, consisting of five first-class battle cruisers, together with a flotilla of perhaps twenty torpedo boat destroyers, was steaming rapidly in pursuit of the fleeing enemy.

The German fleet, while not as powerful as the British, nevertheless presented a formidable array of fighting ships. Three first-class battle cruisers and one second-class battle cruiser and a torpedo boat flotilla greater than that of the English were in line, and it seemed to Frank and Jack that the odds were nearly enough equal for the German commander to give battle.

However, such was not the enemy’s plan; for, once having turned tail to the British, the German ships put on full speed and made as fast as possible for the protection of the German mine field which protected the entrance to Heligoland. It became evident that the enemy would fight only as a last resort.

The British fleet was in full chase. First came the Tiger, the flagship of Admiral Beatty. Next in line was the Lion, a cruiser of the same class, and behind these followed three other powerful English cruisers.

At a command from the flagship, the British torpedo boats headed in the direction of the German ships of the same class, which had borne off a trifle to the north.

So far not a shot had been fired, for the British had not yet drawn close enough to the flying enemy to be within range. Half an hour passed, an hour, and then the great forward turret guns of the Tiger opened upon the rear German ship, which proved to be the Bluecher, a cruiser of the second class.

The first shot went wide, and the second. But with the third shot the British gunners found the range, and a shell dropped squarely upon the bridge of the Bluecher. A veritable cloud of steel and débris of all sorts rose high in the air above the Bluecher, and, falling, showered death among the crew.

A second and a third well-directed shell struck the Bluecher amidships and staggered her. She reeled like a drunken man, seemed about to roll over on her side, then righted herself and steamed on, but slower than before.

Now the Tiger, the first British ship, was upon her; but the Tiger did not stop. She had no time to waste on the Bluecher, already wounded unto death. As she steamed majestically past, however she poured a broadside into the reeling ship; then sped on in pursuit of the other enemies.

Now the Lion also came abreast of the Bluecher, and she, too, as she passed, poured in a broadside. It was more than the sinking Bluecher could stand. One last shot she hurled toward the Tiger, and almost before the British vessel had drawn away from her, she reeled once more and disappeared beneath the sea. As she did so, her crew hurled themselves into the water.

Now the Lion and Tiger had drawn within range of the other German cruisers and their huge shells were raining death and ruin upon them. Suddenly the rear German ship burst into flames, and her pace slackened.

Flushed with success, and with victory within their grasp, the British sailors raised a loud cheer, and the British guns spoke oftener and with greater effect than before.

But the Germans had not been idle. Outranged by the British as they were, they had opened with their great guns the moment the British had come within range. One shell raked the forward deck of the Tiger, and carried away a part of the turret, killing several men. A second struck the Lion, wounding several officers and a number of sailors, though none was killed on the second ship.

Now, with victory almost in their hands, the British fleet, at a signal from the flagship, gave up the chase and fell back. Only the Bluecher had been sunk, though two of the enemy’s remaining three cruisers were in flames and the third had been badly damaged.

A cry of dismay went up from the British when the order to slow down was given. For the moment the men were at a loss to account for this action, and the officers of the various ships themselves were, for the moment, disappointed.

But Admiral Beatty had acted wisely. Ten minutes’ further steaming and the Germans had entered the protection of the mine field, where it would have been death for the British to have followed without a map of the mined area. Admiral Beatty’s action in calling off his fleet was given at the right moment, for had the British followed the chase would have ended disastrously.

When the German cruiser Bluecher had disappeared beneath the waves, the crew of one of the British cruisers had manned the boats and was endeavoring to save the lives of the Germans who had leaped into the water.

Almost two hundred of them had been picked up. Suddenly, right in the spot where the British sailors were engaged in the work of rescue, a torpedo flashed by with a sharp hiss. Had it struck one of the boats, all near must have been killed. A second followed closely after the first, and the British were forced to give up the work of rescue, for to have remained in the spot would have been to invite certain death.

Thus, by firing at British sailors engaged in the task of saving surviving German sailors, a German submarine had been the means of losing several score of German lives.

Meanwhile what of the British submarine D-16, which, before the battle commenced, was bearing Frank and Jack swiftly toward the German fleet?

Beneath the water, Lord Hastings had no way of determining what was going on above. The D-16 had submerged until her periscope was of no value, but Lord Hastings had deemed this advisable, because, had the periscope been allowed to protrude above water, it might have been carried away by a German shell.

Now the D-16, besides being able to remain under water indefinitely, had as before stated an added superiority over other under-the-sea-fighters, for she was able, when pushed to the limit, to make a speed of thirty knots—a speed much greater even than that of any of the cruisers above her.

Therefore, when the British fleet came within range of the enemy, the D-16 was far in advance of her fellows, under the water.

“We’ll leave the big fellows to settle with the German cruisers,” said Lord Hastings calmly. “We’ll try our luck with the torpedo boats.”

Jack and Frank nodded that they understood and approved of the plan.

“I guess the big fellows can take care of them all right,” replied Frank dryly.

“They always have been able to,” agreed Jack.

When, finally, Lord Hastings judged that they must be in close proximity to the German torpedo flotilla, he ordered that the D-16 rise until her periscope showed them their surroundings. Then, as he viewed the scene about him, he stepped quickly back and ordered:

“Submerge!”

Instantly the D-16 dived, and Lord Hastings turned to the two lads.

“I didn’t calculate just right,” he told them. “We went up right in the midst of the enemy.”

“Did they see us?” asked Jack anxiously.

“I don’t know. However, I have the range. Have the men stand by the torpedoes.”

The men sprang quickly to their posts at Jack’s command, and then Lord Hastings gave the order to rise slowly.

Slowly the water was forced from the tanks once more, and gradually the submarine arose, until her periscope once more protruded just above the water.

“No. 2 torpedo!” ordered Lord Hastings. “Ready?”

“Aye, aye, sir,” came the reply of the man, who stood almost at his commander’s elbow, and therefore could plainly hear the command.

For the others, further away, it would be necessary to use the signal board.

“Fire!” cried Lord Hastings.

A sharp metallic click was the only answer, and all on board stood quiet. Lord Hastings kept his eye glued to the periscope.

Then those on board saw him throw up his hand with a gesture of satisfaction, and none needed to be told that the torpedo had gone true.

Now the attention of all was given to the signal board, at Lord Hastings’ side. The men stood at their posts, as did Frank and Jack, awaiting the signal that would mean the firing of another torpedo.

There was not a sound to break the stillness other than the purr of the engine. But the stillness could only be termed such because there were no regular noises. In spite of this a voice could be heard but a few feet away, because of the heavy pressure of the water above.

Suddenly the signal board flashed red. The men read:

“No. 3 torpedo! No. 4 torpedo!”

Lord Hastings had decided upon a bold stroke. He had determined to deliver a double blow to the enemy before he was forced to submerge, to escape the fire of the enemy.

He gauged the range for each torpedo, and this was flashed upon the signal board. Then came the next command:

“Attention!”

Eagerly, though quietly, the men awaited the next command. There was not a nervous hand aboard. All bore themselves with the easy nonchalance that has been the character of the British sailor through all the ages; but their fingers twitched with impatience.

And then the signal board again glowed in burning letters:

“Fire!”

“Click! Click!”

Not another sound, and even these only audible to the men who had launched the torpedoes, and two powerful engines of destruction, aimed true, sped on the errand of death and disaster.

At the same moment the signal board flashed:

“Submerge!”

CHAPTER IV.
A DARING PLAN.

Jack stepped to Lord Hastings’ side and shouted:

“Did we get ’em?”

Lord Hastings shook his head.

“I don’t know,” he replied. “We’ll go up again directly.”

He ordered the submarine to proceed ahead half a mile, and then rise.

This was done, and as the periscope once more took in the sight about, Lord Hastings, who gazed through it, stepped quickly aside and motioned to Jack to peer in. The lad did so, and stepped back with an exclamation of delight.

Frank also peered into the periscope, and uttered an exclamation of pleasure as his eyes took in the scene about.

Speeding forward in the wake of the German cruisers, which the periscope made plain, were all the German torpedo boats, except three. These lay helpless upon the surface of the sea, and it was plainly evident that they were settling rapidly.

Their crews were hurriedly getting out the small boats, and jumping overboard. The D-16 had done her work well.

Frank turned away from the periscope.

“Three notches in the table,” he said to Jack, who stood at his side.

“Right,” replied the latter briefly.

Feeling perfectly secure now, Lord Hastings ordered that the submarine be brought to the surface, and followed by Frank and Jack, he stepped out on the bridge.

They stepped out just in time to see the sinking of the Bluecher by the British cruiser Lion, and from their posts they watched the chase of the others. Frank and Jack were greatly surprised when the British admiral signalled for his ships to draw off.

“Great Scott!” exclaimed Frank. “He had them right in his hands. Why didn’t he follow ’em up?”

“It’s too deep for me,” said Jack, in some disgust.

“Come, come,” said Lord Hastings. “You must give the Admiral credit for having some sense, you know.”

“Then why did he do it?” questioned Frank.

“Why,” said Lord Hastings, “because, had he followed another mile, the entire British fleet might have been sent to the bottom.”

“What do you mean?” asked Jack.

“Mines,” replied Lord Hastings. “The enemy has reached the protection of his mine field.”

“I see,” said Frank, somewhat taken aback. “Of course. I should have known that the Admiral had some good reason for not following up his advantage.”

“You let your feelings get away with you sometimes,” said Lord Hastings.

“Well, I’ll promise not to do so any more,” said Frank.

“I wouldn’t make any rash promises, if I were you,” said Jack, with a smile.

“Well, I mean it,” said Frank.

“Oh, well, if you mean it, all right. Only you are liable to forget yourself if you are not careful.”

Jack turned to Lord Hastings.

“Which way now, sir?” he asked.

Lord Hastings was silent for some moments, but said finally:

“I guess we might as well cruise about here. Some of these other fellows are likely to come sneaking out, and we may nab them.”

“If you please, sir,” said Frank, “I believe I have a better plan than that.”

“Let’s have it,” said his commander briefly.

“Well,” said Frank, “these German submarines have been making raids on the coast of England. What’s the matter with our doing a little of that kind of work?”

“By Jove!” said Jack. “A good idea. What do you say, sir?” turning to Lord Hastings.

Lord Hastings was plainly undecided. It was evident that he looked with some favor upon the plan, but he hesitated, not because of fear, but rather because he was not entirely certain that it could be accomplished successfully.

“Where would you plan to make an attack?” he asked of Frank.

“Why, right in Heligoland, sir.”

“But the mines?”

Frank shrugged his shoulders.

“The Germans don’t pay much attention to our mines,” he said.

“Well, no, they don’t, that’s true,” agreed Lord Hastings.

“Besides,” said Jack, “we can go beneath the mines.”

“I guess we could do that,” agreed Lord Hastings. “While we cannot tell just where the mines lay, we have, nevertheless, a first-class map of Heligoland and the sea surrounding, and by paying careful attention we may be able to get through safely.”

“Then we shall make the attempt, sir?” asked Frank eagerly.

Lord Hastings smiled.

“Yes,” he said quietly.

“Good!” cried Jack and Frank in a single voice.

“It has always seemed strange to me,” said Frank, “why such an attempt has not been made before. The Germans do it. Why haven’t we?”

“Well,” said Lord Hastings, “I suppose the main reason is that Heligoland is too far away.”

“But the Germans have done it,” said Jack.

“True; but you must remember they have established a naval base at Ostend; and the distance from Ostend to Dover, and other British coast towns, is not as great as from the British coast to Heligoland.”

“I hadn’t thought of that,” said Frank. “However, I know this much. In every war in which the United States has engaged, some such desperate attempt has resulted successfully. Take Dewey at Manila, or Farragut at Mobile Bay. Both went right in, regardless of mines and forts.”

“That is true,” said Lord Hastings. “No one can dispute the bravery and daring of the American sailor. Nevertheless, it has always seemed to me to be foolhardy. Had it been absolutely necessary, it would have been different. But a blockade would have been just as effective.”

“I don’t know about that,” replied Frank. “Ever since the beginning of this war I have wondered why a British fleet didn’t try to get at the Germans.”

“Well, as nearly as I can make out,” said Lord Hastings, “it is because it has been believed unnecessary to take such a chance.”

“Of course,” said Frank, “we, in this submarine, will have a better chance of performing such a raid successfully than any other vessel, because we can go beneath the water, and stay there until we get ready to come up.”

“Right you are,” agreed Jack. “All we have to do is to figure the distance from here to a point where, being sure it is not mined, we wish to rise. Then, calculating our speed, we shall know just when to come up safely.”

“Perfectly simple,” said Lord Hastings with a smile, “if we don’t hit a mine before we get there.”

“Don’t you think, sir, that by going beneath the mines we will be successful?”

“If I didn’t I wouldn’t make the attempt,” said Lord Hastings dryly. “I remember how you did it when you sank that Turkish cruiser in the Dardanelles.”

“And had we had this vessel at our disposal,” said Jack, “we could have done considerable more damage. As it was we had to get back before we exhausted our air supply.”

“We have an advantage in that respect. There can be no question about that,” said Lord Hastings.

“Well, when shall we start, sir?” asked Frank.

“Immediately,” was the reply.

The three turned their eyes over the sea to where the British fleet, retiring, could be seen moving toward the west. One of the large cruisers, the Tiger, was being towed by a torpedo boat.

“Hope she is not badly damaged,” said Jack, noticing how the British cruiser staggered.

“She looks fit enough,” said Frank.

“The trouble is you can never tell by the looks,” said Lord Hastings. “However, I guess she is in no danger of sinking.”

“Let us hope her death list is small,” said Jack fervently.

“Let us hope so,” agreed Lord Hastings. “Come, we may as well go below.”

The commander of the D-16 descended from the bridge and the lads followed him.

“We may as well submerge here,” said Lord Hastings, “for every foot we advance on the surface of the water is putting us in the way of hitting a German mine. We can’t be too careful.”

“But it is hardly likely there would be any about here, sir,” said Frank.

“Have you forgotten what it was that caused Admiral Beatty to give up the pursuit of the enemy?” asked Lord Hastings.

“That’s so, sir,” said Frank. “I had forgotten.”

“Besides,” said Jack, “the Germans may have dropped more mines to cover their retreat.”

“Exactly,” said Lord Hastings.

“Well, let’s dive then,” said Frank.

“The sooner the better it will suit me,” said Jack.

“So be it then,” from Lord Hastings. “You may give the order, Mr. Templeton.”

Jack obeyed, and slowly, as the water was let into her tanks, the D-16 sank and sank, until, certain that she was beneath the enemy’s mines, Lord Hastings gave the command: “Full speed ahead!”

CHAPTER V.
TROUBLE ON BOARD.

“It’s as well to go quickly,” Lord Hastings said, giving his reason for ordering full speed ahead. “I hardly anticipate they have mined very deep here. We’ll slow down further along.”

“If we bump a mine,” said Frank, “I can’t see that it will make any difference whether we are going fast or slowly.”

“It won’t make much,” agreed Jack dryly.

According to Lord Hastings’ calculations, which proved to be correct, they were now off the coast of Holland.

Several hours passed, and then, at Lord Hastings’ command, the solid glass front of the submarine was plunged into utter darkness and the powerful searchlight brought to bear on the water ahead, while, at the same time, the speed was reduced to seven knots.

In spite of its powerfulness, the searchlight lighted up the water for only a short distance ahead, and, as Lord Hastings said, should a mine be seen ahead prompt action would be necessary to save them from disaster.

Frank took his place just behind the searchlight, while the compartment behind was closed that no light might enter from without, thus adding a little to the effect of the searchlight.

His watch was set for two hours, and he had sat most of that time with eyes straight ahead, when he became conscious that the door behind him was being pushed slowly open.

Certain in his own mind that his watch was not up, and mindful of Lord Hastings’ order that the door be not opened unless absolutely necessary, Frank nevertheless did not take his eyes off the sea ahead, but called out:

“Who’s there? What is it?”

There was no answer.

“Something wrong,” muttered the lad to himself, and acted upon the instant.

Through the little tube at his elbow he shouted a command:

“Stop her!”

At the same moment, even as he felt the sudden shock as the submarine paused abruptly in her pace, he sprang from his seat and turned toward the door, ready for anything with one hand on his automatic, for he felt sure that he was in danger.

In the darkness behind he could see nothing, but the slight squeaking of a board gave evidence of another presence. Frank, with the searchlight behind, was in full view of the other, and the lad realized it.

With a quick backward leap he snapped off the searchlight, and then dropped quickly to the floor, even as a figure rushed toward him in the darkness.

Frank’s ruse undoubtedly stood him to good advantage. A foot struck his prostrate body, and the figure of a man pitched over him, muttering a fierce imprecation as he fell to the floor.

Before the latter could rise, Frank grappled with him. Quickly reversing his revolver, he brought the butt of the weapon down in the direction in which he judged the man’s head to be. It struck something soft, and a guttural howl of pain went up.

“A spy!” Frank found time to think to himself.

But he had not struck the man’s head, only a hand which had been outstretched, and before he could draw his pocket searchlight to ascertain what damage he had done, the lad felt a pair of arms about his neck, and a hand seeking to entwine itself in his throat.

His revolver he found now to be of no use, so he dropped it and struck out blindly with his bare fists. Once, twice, his fists found their mark, and each time a blow went home the lad was rewarded by hearing cries of pain from his opponent.

As the two struggled, there flashed before the lad a vision of a man running from where the D-16 lay in drydock some days before.

“I guess we have got him at last,” the lad muttered between his teeth, and putting all his force behind one more blow, he struck out savagely.

The arms about his neck relaxed their pressure and the man sank to the floor while Frank felt the form grow limp beneath him.

The lad stood up and walked across the little room to snap on the searchlight.

As he did so the man on the floor came quickly to his feet, and before Frank could stop him, had darted from the room and disappeared. Through the door he left open streamed a faint light.

Frank sprang after the retreating figure with a cry of anger. Dashing out of the door he bumped squarely into the figure of another man advancing toward him. Without pausing to see who the newcomer might be, Frank grappled with him.

“Here, here, what’s the meaning of this?” asked a well-known voice, and Frank released his hold and stepped back.

The newcomer was Lord Hastings.

“What’s the matter with you?” asked the commander of the vessel. “Have you gone crazy? I stopped the ship in response to your command and when I asked you, through the tube, what was wrong I didn’t get an answer. And now you jump on me. What’s the matter?”

“Spy aboard, sir,” replied Frank briefly.

“What!” exclaimed Lord Hastings, starting back.

“Spy aboard, sir,” repeated Frank.

“Impossible!” exclaimed Lord Hastings. “Have you lost your senses? How could a spy have got aboard?”

“As to that I don’t know,” replied the lad, “but nevertheless there is a spy aboard. I’ll stake my life on that.”

Then he proceeded to relate what had occurred.

Lord Hastings grew very grave. He took Frank by the arm.

“Come with me,” he said quietly.

He led the way to his own cabin, where he passed the word for Jack. The latter arrived almost immediately, and the situation was explained to him.

“I believe,” said Frank, “that the man is the same I saw lurking about the ship yard before the D-16 was put into commission.

“So you saw him, too?” exclaimed Jack.

“Yes, I saw him, but I didn’t know you did,” replied Frank.

“I didn’t say anything because I thought I must be wrong,” said Jack. “It didn’t seem possible a German spy could have gained admittance there.”

“Just what I thought,” said Frank.

“Do you suppose the man who attacked you just now is one of the crew?” asked Lord Hastings.

“Who else could he be, sir?”

“But I could have sworn by the members of my crew. They have all been in the service for years and are British to the backbone.”

“There must be one who isn’t,” said Frank, “for when I struck him he let out a stream of German oaths.”

“Would you recognize him?”

“I am afraid not. It was perfectly dark, and I didn’t even get a glimpse of his face. All that I could make out was that he was a big man.”

“We have several big men in the crew,” said Lord Hastings.

“But,” said Frank suddenly, “I might be able to identify him if I got a look at his hand.”

“Why?”

“I hit him with my revolver butt. I thought it was his head but it must have been his hand.”

Lord Hastings, who had been seated, stood up.

“We’ll see,” he said.

He walked to the door and summoned the chief gunner’s mate.

“Johnson,” he said, “take a brace of automatics and summon every man of the crew here, coon, engineer and all. Don’t let a single one get the drop on you.”

Johnson looked blankly at his commander.

“Why—why——” he stammered.

“There is a spy aboard, Johnson,” said Lord Hastings calmly. “Hurry.”

The old man drew himself up and touched his cap.

“Aye, aye, sir,” he said quietly. “I’ll bring ’em.”

He turned and marched rapidly away.

“I happen to know he’s not your man,” said Lord Hastings with a slight smile, “for I was standing right beside him when I got your command to stop.”

“We had better let Johnson line them all up outside the door, and question each man separately, sir,” said Frank.

“A good suggestion,” said Lord Hastings.

They sat quiet for perhaps five minutes, and then Johnson’s voice came from outside.

“I’ve got ’em all here, sir.”

Frank arose and walked out the door. There stood the full crew of the ship with arms in the air, under the muzzles of Johnson’s two automatics.

“Send them in one at a time, Johnson,” Frank ordered.

“Aye, aye, sir,” replied the old man, and waving his revolver at one he commanded: “You first.”

The first sailor was white of face and evidently badly frightened. He entered the room slowly and came to attention before Lord Hastings.

“Your name?” demanded the commander.

“Brice, sir.”

“Any other name?”

“Yes, sir, Harvey, sir.”

“No; I mean were you ever known by another name; an alias?”

“Well, sir,” replied the sailor plainly confused, “no, sir, yes, sir. Before I enlisted I was known as Ryan, sir.”

“That’s hardly German,” said Lord Hastings. “And why did you change your name?”

“A little trouble with the police, sir, if you must know.”

At this moment Frank, who had approached closely, suddenly spoke in German.

“Your name?” he commanded.

The sailor stared at him blankly.

“He’s not the one,” said Jack. “His surprise is genuine enough. Call the next.”

“Stand over there in the corner,” said Frank to the sailor. “Jack, you keep them covered as I line them up. We must be careful.”

“Send in another, Johnson,” called Lord Hastings.

A second sailor appeared in the door. His right hand was wrapped in a handkerchief!

CHAPTER VI.
THE SPY.

Frank’s hand dropped quickly to his revolver.

“Stand over there,” he commanded in a harsh voice.

The man obeyed, and Frank approached and looked at him carefully.

“He is about the same build, sir,” he said, turning to Lord Hastings.

Lord Hastings confronted the sailor.

“Your name?” he demanded.

“Thompson, sir,” was the reply, and the man let fall his arms, which he had kept above his head when he entered.

Immediately Frank’s revolver flashed forth.

“Hands up there, Thompson,” he said quietly.

Plainly frightened, Thompson obeyed.

“How long have you been in the service?” demanded Lord Hastings.

“Ten years, sir.”

“Ever known by any other name?”

“No, sir.”

“Are you of German descent?”

“There is not a drop of German blood in me, so far as I know, sir.”

“Do you speak German?”

“A little, sir.”

Lord Hastings looked at the man closely, and demanded suddenly:

“What is the matter with your hand?”

“I was helping Smith in the engine room, sir, and a heavy block fell on it, sir.”

“Let me see it.”

Slowly the sailor unwrapped the bandage and exposed his hand. It was very red across the top, and Frank, glancing at it, believed that the mark could have well been caused by the blow of a revolver butt.

“I should say he is the man, sir,” he said quietly to Lord Hastings.

“It would seem so,” was his commander’s reply, “still we must be positive.” He turned again to the sailor. “Is it not true,” he asked, “that only a few moments ago you attacked Mr. Chadwick, and that your wounded hand is the result of a blow from his revolver?”

The sailor looked at his commander in surprise, that seemed genuine enough.

“No, sir,” he replied quietly.

“Then you deny you are a German spy?” asked Lord Hastings.

The sailor started back, and his face turned red.

“A spy, sir!” he cried. “Me a spy? Why if there is one country under the sun for which I would not turn a hand, it is Germany.”

“Circumstances are much against you, in spite of your protestations of innocence,” said Lord Hastings gravely.

“But Smith, the engineer, can vouch for me, sir, and so can Black, who was in the engine room when I injured my hand. Call them, sir.”

“Well, I’ll call them,” said Lord Hastings, “but I doubt if it will do any good.”

At a command from Lord Hastings the engineer and a sailor named Black were sent into the room.

Lord Hastings turned to the engineer.

“Were you in the engine room when Thompson injured his hand?” he asked.

Smith shifted uneasily from one foot to the other.

“Yes, sir,” he replied at length.

“He says that a block fell on his hand. Is that true?”

“Well, sir, I—I——” stammered Smith.

“Come, sir, this is a serious matter,” said Lord Hastings sternly.

“No, sir, it isn’t true,” said Smith. “He——”

“That is enough,” said Lord Hastings. He turned to Black. “Thompson says you were there. Is it true that a block fell on his hand?”

“No, sir,” said Black. “He——”

“That’s enough,” said Lord Hastings again. “It looks to me as if you were guilty.”

“If you please, sir,” said Thompson quietly, “will you allow me to ask Smith and Black one question?”

Lord Hastings nodded his head in assent.

“Smith,” said Thompson, “how did I injure my hand?”

“Why,” said Smith, “you miscalculated, and instead of putting it against Black’s head, you put it against the door.”

Thompson turned to Black.

“Is that true?” he asked.

“Yes,” replied Black.

Thompson turned to Lord Hastings.

“That should be enough, sir,” he said quietly.

“What is the meaning of this?” demanded Lord Hastings, looking from one to the other of the three men.

“It’s plain enough,” said Jack stepping forward. “Thompson and Black were settling an argument of some sort by the use of the fists. And Smith, I take it, was the referee. Am I right?”

“Right you are, sir,” replied Smith. “But we didn’t——”

“Never mind, never mind,” said Jack with a wave of his hand. “All of you line up there alongside Brice.” He turned to Frank and Lord Hastings. “We are on the wrong track,” he said.

“So it seems,” replied Lord Hastings, “but appearances were against him. We’ll have to look further.”

One after another the members of the crew were examined, but in spite of the best efforts put forward by Lord Hastings, Jack and Frank, not one of them could be tripped up.

“But it must have been one of them,” said Frank, after all had been examined and given satisfactory accounts of themselves. “It must be one of them. I certainly didn’t dream I was attacked. But who was it?”

“Can there be a stowaway aboard?” asked Jack.

“I never thought of that,” exclaimed Frank. “Shall I have the ship searched, sir?”

“Immediately,” ordered Lord Hastings. “We’ll leave Johnson here to guard these men, while we make a thorough search.”

From stem to stem they searched the little submarine. Not a single movable obstacle but what they moved. It was as systematic a search as it was possible to conduct, but there was no sign of a stowaway.

“Well, there is no one here,” said Frank, when the search had been concluded. “Therefore, it must have been a member of the crew.”

They went back to Lord Hastings’ quarters, where Johnson still stood on guard. Lord Hastings looked them over carefully, then spoke.

“Men,” he said, and his voice was very grave. “Some place on this vessel there is a traitor. We have searched high and low for some sign of a stranger, but we could find no one. Therefore, the spy must be among you. Will he step forward and save his companions from the finger of suspicion?”

Not a man stirred.

“Then——” began Lord Hastings, but he was interrupted by a sudden motion of the vessel, which seemed to be flying up through the water.

Up to this time it had been perfectly stationary.

“What’s the meaning of that?” cried Lord Hastings when he had recovered his balance.

“I should say someone was forcing the water out of the tanks, sir,” replied Jack calmly.

“But every man is in this room,” replied the commander.

“You forget the stowaway, sir,” said Frank.

“But there is no stowaway.”

“There must be a stowaway! How else do you account for this? The vessel could not do it by itself.”

There was still a perceptible motion of the vessel.

“We’re rising,” cried Jack in alarm. “Someone has tampered with the tanks. We are likely to hit a mine.”

Lord Hastings turned to the sailors.

“Men,” he said quickly, “until this matter has been finally settled, I must let you all go. But, each of you keep an eye on your companion, and at the first sign of treachery, shoot him. Search the ship.”

He followed Frank, who had dashed toward the compartments in which were located the water tanks, by means of which the vessel rose and submerged. As he dashed forward there came to his ears the sound of a shot.

The commander of the D-16 redoubled his stride and the men, also having heard the shot, piled after him. As he passed the door to the engine room, the figure of a large man, rushing forth at that moment, struck him squarely and knocked him down.

Lord Hastings was up in a moment and had his opponent beneath him. The latter was a powerful customer, however, and had it not been for the crew, who rushed to their commander’s aid at that moment, it would have fared badly with him.

But the crew, angry that they had been under suspicion, now that they believed they had found the man who was responsible for their predicament, leaped upon the man and soon had him bound securely. At that moment Frank and Jack came upon them.

“Well, I see you have him,” said Frank quietly.

“Yes,” replied Lord Hastings, “but what was the shot I heard?”

“Oh that,” said Frank. “He took a shot at me when I came upon him as he was fooling about the tanks.”

“Did he hit you.”

“No; just knocked my gun out of my hands. But you see, there was a stowaway on board.”

“But where on earth was he hiding?”

“I found the hiding place,” said Frank quietly. “It is in the engine room, right where he could do the most damage should occasion require. He had built himself a little stage beneath the floor, where he could lie, only coming out when it was safe.”

“But why hasn’t he sunk us long ago? That’s what I would like to know.”

“I think I can answer that,” said Jack. “I should say that his work was to find out the specifications of the D-16—how she attains her great speed, and how she can remain indefinitely under water. In some way word of her building must have reached the enemy. Am I right?” he asked of the prisoner.

The latter shrugged his shoulders.

“Think as you please,” he said. “Whatever my work, I have failed.”

“Yes, you have failed,” said Lord Hastings. “And you know the penalty?”

“Yes,” said the prisoner quietly, “it is death.”

“Yes,” repeated Lord Hastings slowly, “it is death!” Then to the men: “Guard him as you value your lives.”

Motioning to Jack and Frank to follow him, Lord Hastings led the way to his cabin.

CHAPTER VII.
DEATH OF THE SPY.

“What will you do with the spy, Lord Hastings?” asked Frank.

“Shoot him,” was the brief reply.

Frank was silent for some moments.

“It’s terrible to think of it,” he said at last. “Still, I suppose it must be done.”

“It must,” returned Lord Hastings.

“Will there be need of a trial first, sir?”

“A trial, of course, is only a formality. Nevertheless, he must have one.”

“When, sir?”

“The court martial will sit in half an hour.”

“And will be composed of how many, sir?”

“Six. Mr. Templeton, yourself, Johnson, Smith, one of the sailors and myself. It will sit here in my cabin.”

“Very good, sir. I shall be here.”

Half an hour later the prisoner faced his judges. Lord Hastings addressed him.

“Prisoner,” he said, “what have you to say in extenuation of your actions?”

“Nothing,” was the brief response.

“Have you anything to plead why sentence of death should not be pronounced on you?” continued Lord Hastings.

“I have nothing whatever to say,” was the firm response.

The six judges consulted together for some moments. Then Lord Hastings turned again to the prisoner.

“As president of this court martial,” he said slowly, “I sentence you to be shot at six o’clock.”

He drew a watch from his pocket and glanced at it.

“It is now five,” he said. “You have one hour in which to prepare yourself to meet your maker.”

The prisoner bowed his head in assent. Then, at a signal, he arose and was conducted from the room.

Six o’clock came all too swiftly for Frank and Jack, who could but look with horror upon this cold blooded way of disposing of a man, simply because he was a spy.

The D-16, feeling her way carefully, had come to the surface, and now the prisoner was conducted to the bridge. He took his stand at one end and waving aside a proffered bandage, faced his executioners unflinchingly.

A firing squad of six men took their positions opposite him. Much to his chagrin, Jack had been put in command of the squad, and it was his duty to give the word that would snuff out the life of a fellow being.

But Jack was not the lad to refuse to obey orders, and now he stood behind the squad.

“Ready,” he said calmly.

“Take aim!”

But before he could give the word to fire, the prisoner, who up to this moment had been standing with folded arms, suddenly flung himself into the sea.

“Fire!” cried Jack, and the sailors poured a volley after him. Then all rushed to the rail and watched for him to reappear.

A few minutes later a head appeared a short distance away. It became at once apparent that the spy had not been touched.

Immediately Jack rushed to the side of the vessel and also flung himself into the sea. The erstwhile prisoner saw his action and struck out vigorously toward the south, where, in the gathering darkness, he could make out dimly a strip of land.

But Jack was a powerful swimmer and gained rapidly on the spy.

Perceiving that he could not out-swim his pursuer, the spy slackened his stroke, and just as Jack came up to him, dived. As he went down, he caught Jack by the legs and pulled him under also.

Taken at a disadvantage Jack struggled in vain to free himself. He was at a further disadvantage also, for the spy, before going under, had caught a long breath; whereas Jack had gone under sputtering and gasping.

But help came to Jack from a source he did not expect. When he had jumped into the sea in pursuit of the spy, Frank had done likewise, for he divined that Jack might have trouble recapturing the prisoner. While he was not such a powerful swimmer as Jack, he was nevertheless close at hand when the spy pulled his chum under.

Frank acted without an instant’s hesitation. Drawing his revolver and grasping it by the barrel, he also dived. Down and down he went, and then close beside him he became aware of the struggling figures.

The water was very dark, but the lad could dimly distinguish the form of his friend from that of the spy. Going close, he raised his revolver and brought it down on the spy’s head with all his force. At the same time he stretched forth his other hand, and seized the spy by the shoulder.

Freed of the hold on his legs, Jack immediately shot to the surface, where he filled his lungs with fresh invigorating air. A moment later Frank, still grasping the spy by the shoulder, appeared by his side.

“Lend a hand,” he called, “and we’ll get him back aboard.”

Jack, now greatly refreshed, did as his chum ordered and the two lads, supporting the body of the spy between them, swam back to the submarine, where willing hands helped them over the side.

Lord Hastings immediately took charge of the spy.

“Stretch him out there till he recovers consciousness, and then proceed with the execution,” he ordered.

The body of the spy was stretched out on the deck, and two sailors bent over him. Then one started back, and took off his cap.

“The execution will not take place,” he said.

“What do you mean?” said Lord Hastings. “Is he——”

“Yes,” interrupted the sailor, “he is dead.”

“By George!” muttered Frank, “that blow over the head.”

“No,” said the sailor, “it is the water that did for him.”

“I’m glad of that,” said Frank simply.

“Prepare the body for burial immediately,” ordered Lord Hastings. “We’ll remain on the surface until after he has been buried, then we’ll submerge and continue our course.”

The work of preparing the spy’s body for burial was only a question of minutes, and when it had been turned over to the mercies of the sea, Lord Hastings gave the command:

“Submerge immediately, Mr. Templeton.”

All descended from the bridge, the little vessel was made snug and comfortable, and disappeared from the surface of the sea.

“Shape your course due east, Mr. Templeton, and steam at 7 knots,” ordered Lord Hastings. “Mr. Chadwick, you will take your post and watch for mines.”

“Very good, sir,” replied both lads, and departed on their respective duties.

In the darkened room in the bow of the vessel, with the powerful searchlight lighting up the murky water ahead, Frank kept careful vigil. Hour after hour he sat there in silence, hardly moving from his first position.

The D-16 forged ahead but slowly, for there was no need of undue haste and Lord Hastings was not minded to take unnecessary chances.

Frank glanced at his watch.

“Midnight,” he muttered to himself. “Only one more hour and then I can turn in for the night.”

Still the minutes passed without incident. Finally, at a few minutes to one, Frank, after a second glance at his watch, arose and stretched himself.

“Guess nothing will turn up in my watch,” he told himself.

But the lad was mistaken.

For one moment he had taken his eyes from the water ahead, and now, glancing forth once more, he beheld a sight that moved him to instant action. His eyes fell upon a large object directly ahead, a scant hundred yards.

Quickly the lad jumped to the bell that signalled the engine room. And almost as quickly the speed of the vessel was checked. But the nose of the submarine was now but inches from the dark looking object ahead.

Lord Hastings’ face appeared in the room.

“What’s the matter?” he demanded.

“Looks like a mine, sir,” replied Frank quietly.

Lord Hastings advanced until he could get a good look at the object. He peered at it long and carefully, then turned to the lad.

“You are right,” he said. “It is a mine. Had you perceived it an instant later we undoubtedly would be in the land of the missing by this time.”

Frank flushed at this, for he realized perfectly that had he been paying strict attention to his duties, the submarine would not have come this close to danger of destruction. But he said nothing.

The mine extended well up toward the surface of the water, but the bottom of it was in plain sight.

“I suppose the best thing to do is to dive under it,” said Lord Hastings.

“My idea, too, sir,” agreed Frank.

Lord Hastings turned on his heel and left the compartment, and a moment later the vessel began to sink lower and lower into the sea. Frank still stood on watch, and when he was certain that the D-16 would pass beneath the mine without danger of striking it, he gave the signal and the vessel headed forward once more.

Lord Hastings entered the compartment again.

“The chances are there are more of them,” he said, “so we shall have to be very careful. I’ll have Mr. Templeton take the next watch, for we cannot keep too sharp a lookout.”

Frank nodded his head in assent. Lord Hastings left.

Five minutes later Jack appeared at Frank’s side and the latter turned to go. Suddenly he whirled about and spoke to his chum.

“You must be more careful than I was,” he said quietly. “I was almost the means of sending us all to the bottom for good.”

“What do you mean?” asked Jack in surprise.

Frank explained.

“Well,” said his chum consolingly, “a miss is as good as a mile, you know.”

“Nevertheless,” replied Frank, “the second might not be a miss. Keep your eyes open.”

“I’ll keep them open, never fear,” said Jack. “Now, you go to bed.”

“All right,” said Frank, and left his friend alone.

CHAPTER VIII.
HELIGOLAND.

“Off there,” said Lord Hastings, pointing over his shoulder, “lies Heligoland, one of the strongest harbors in the world, and regarded by the Kaiser and his subjects as impregnable. A raid by an enemy has been deemed as impossible by strategists.”

“Nevertheless,” said Frank drily, “it is not impossible, as the Kaiser and his subjects will find out.”

“As I understand it,” said Jack, “Heligoland is a natural stronghold.”

“To a certain extent, yes,” replied Lord Hastings. “Heligoland, as you know, is an island, and nature has done her best to make it immune from attack. To nature’s work has been added the brains and brawn of the best German strategists and workers. An attack by a hostile battle fleet could have but one result—failure. But, so far as I have been able to determine, there as yet has been nothing devised that will ward off the attack of a submarine.”

“Except mines,” said Frank.

“True. But it is certain there can be no mines in the harbor proper, for they would be an eternal menace to the German fleet. Of course the entrance is strongly guarded by mines and the powerful guns of the forts. But it is our business to get beneath these and torpedo a few of the enemy’s vessels before we are discovered.”

“And then?” asked Jack.

“Why, then,” said Lord Hastings, “we shall make off as fast as possible to return at some future date, perhaps, and pay our respects once more. As I see it, there is but one thing that is likely to cause us any trouble.”

“And that, sir?” asked Frank.

“The enemy’s submarines,” replied his commander.

“But we have the heels of them, sir,” said Jack.

“True,” replied Lord Hastings, “but the trouble is we are liable to run into a net of them, and in that event we would have to fight. To my knowledge, there has never been a battle of under the sea vessels, and what the result might be it is impossible to determine.”

“Well,” said Frank, “we shall have to take a chance. That’s all.”

“That’s all,” agreed Lord Hastings.

Lord Hastings turned to the chart of the harbor of Heligoland and bent over it eagerly. The lads peered over his shoulder.

“We are down as deep as it is safe to go,” said the commander of the submarine. “The chart shows that the water is not so very deep here, and as it is all the guide we have, we must be careful.” He turned to Jack. “Proceed at five knots,” he commanded.

Jack gave the necessary command, and the D-16 slowed down perceptibly.

For many minutes there was intense silence, broken at last by Lord Hastings.

“I should say,” he said, “that we must now be in the harbor. I am positive we have passed under the mines safely.”

“Then shall we go up, sir?” asked Frank eagerly.

Lord Hastings hesitated for a moment, and then replied:

“Yes, we may as well.”

Jack took this as a command, and gave the necessary order.

Slowly the D-16 began to rise.

Lord Hastings glanced at his watch.

“Seven o’clock,” he said quietly, “and there should be no moon. A good night for our work.”

With the periscope barely reaching above the surface, the work of forcing water from the tanks was stopped. Lord Hastings stood quietly viewing the scene about him, and to his eyes was exposed an awesome sight.

Right in the midst of the giant German battle fleet he peered, and as he did so he could but wonder to himself that so powerful and so magnificent a fighting machine apparently had been afraid to venture forth and give battle to the fleet of England, powerful as the latter was.

The D-16, before ascending, had penetrated to the very middle of the harbor, and now that she was close to the surface, the powerful binoculars at the bottom of the periscope made clear the many vessels of the German fleet in all their majesty.

Clouds of smoke floated from their smokestacks, and this suggested something to Lord Hastings.

“Ready to set forth at any time,” he muttered to himself. “Just afraid, that’s all.”

He stepped away from the periscope, and Jack took a turn.

“Great Scott!” he exclaimed, turning away at last. “To think that a fleet the size of that should be afraid to give battle.”

“It does seem strange,” said Lord Hastings.

Frank now peered into the periscope, and as he looked one of the German dreadnoughts began to move from her moorings.

“One of ’em’s coming out,” cried Frank. “She’s headed for the open sea.”

“I thought they might have determined to try a little raid when I saw all that smoke,” said Lord Hastings. “We’ll stop her, at any rate.”

He took Frank’s place at the periscope and then commanded:

“Ten knots ahead, Mr. Templeton, and prepare for action!”

Jack jumped to obey this order, and a moment later the D-16 was in fighting trim. The engines throbbed and fussed, the water parted before the sharp prow of the vessel with an angry hiss, and the men stood at their posts.

The signal board flashed its first command, in letters of fire.

“No. 1 torpedo!”

The gunner was ready, and the second command—“attention”—was scarcely necessary.

Now, through the periscope, Lord Hastings gauged the range, and the signal board showed:

“Submerge!”

Almost at the same moment a second command showed plainly.

“Fire!”

“Click!”

The first torpedo sped on its way, and at the same moment Lord Hastings shouted in Jack’s ear:

“Due north, Mr. Templeton. Fifteen knots!”

The D-16 leaped ahead, and at the distance of half a mile, rose slowly to the surface.

Lord Hastings and his two officers ascended to the bridge, where they took in the scene about them with their night glasses.

In the very center of the German fleet, a huge battleship was sinking. The glare of the searchlights of the others showed her plainly to the eyes of the British. Terrified cries carried over the water. The confusion aboard the sinking vessel was terrible to behold.

Men ran hither and thither about the decks, yelling and fighting, so great was their fear. From other vessels of the fleet small boats put into the sea, to pick up those who had jumped from the wounded warship.

Suddenly there was a terrific explosion, and the German warship sprang into flames, lighting up the sky for miles around. But the D-16, in the very edge of the fiery glare, so far had been unnoticed.

“They evidently think it was an internal explosion,” said Lord Hastings quietly to the two lads.

“Looks like it,” replied Jack, “or they would certainly be using their searchlights to make out the presence of an enemy.”

“They haven’t the slightest idea an enemy could have penetrated the mined area safely,” replied the commander of the submarine. “But look, she is about to go.”

He pointed toward the wounded German warship. His words were true. Amidst the flashing searchlights of her sister ships, the dreadnought reared high in the air. There she poised herself for a moment; then, slowly, midst a broad circle of brilliancy, she sank, the cries of those of her crew still aboard mingling with the shouts and commands from the other ships making the night hideous.

A fierce red flame, from the top of her to the very water’s edge, where it hissed loud and long, enveloped the sinking ship, as the smoke arose in a dense cloud. Came another dull explosion, and the ship split in twain. For a moment there were two distinct sheets of flame, and then the fore and aft parts of the vessel disappeared beneath the water simultaneously.

“Well, she’s gone,” said Lord Hastings. “Now for the next one.”

“We are safe enough here, sir,” said Jack, “and we are close enough to hit her. Why not fire without submerging?”

“All right,” replied his commander quietly. “Order No. 2 torpedo launched immediately,” and he gave the range.

Jack hastened below, only to hurry back upon the bridge again, which he reached just in time to see the second ship in the German line stagger, and sway drunkenly.

Again loud cries of fear carried across the water, and the searchlights of the still unhit German ships played upon the second wounded vessel.

“No. 3 and No. 4 torpedoes right into the midst of them!” cried Lord Hastings, and Jack jumped below to give the command.

“Click! Click!”

Two more terrible engines of destruction sped on their way.

Jack sprang back to the bridge to watch the effect of these shots.

And the effects were terrible, as the watchers could plainly make out.

Confusion reigned throughout the German fleet. Not a ship but on which there was panic, and the officers were having serious trouble with the crews.

For there could no longer be any doubt in the minds of the Germans as to the cause of the three terrific explosions that now shattered the stillness of the night.

“Boom! Boom! Boom!” they came, and showers of steel, iron, wood and débris rose high in the air, to be scattered far across the surface of the sea.

Now the searchlights of the uninjured German ships left their sinking sister ships and flashed swiftly across the water. Suddenly the D-16 was lighted up by a circle of light as bright as day.

“We are discovered!” cried Frank, and at the same moment Lord Hastings gave a command:

“Down, quick!”

He led the way through the conning tower with rapid strides, and the lads hurried after him.

“Submerge!”

A moment more and the D-16 was again beneath the sea, safe from chance German shells, and steaming toward the east.

CHAPTER IX.
A DESPERATE VENTURE.

“Which way now, sir?” asked Jack.

Lord Hastings hesitated.

“They will probably be laying for us toward the west with their submarines,” he said, “and while we may be able to get by, it will be desperate work.”

“Then why not go due east, sir?” asked Frank.

“The Kiel canal is due east,” replied Lord Hastings.

“What of that, sir?”

“What of it? Surely, you would not suggest forcing a passage of the Kiel canal?”

“I don’t see why not, sir.”

Lord Hastings looked at the lad with surprise written all over his face.

“By Jove!” he said at last. “When it comes to finding ways of getting into trouble, you are the limit, as the Americans say.”

“But don’t you think it could be done, sir?” asked Frank.

“Well, I don’t know,” replied his commander. “It might be done, yes. And then again it might not. But what would be our object in getting into the Baltic?”

“Well, I understand that the Russians are having considerable trouble there,” replied Frank, “and we might be able to lend them a hand.”

“That’s true, too,” replied Lord Hastings. “I hadn’t thought of that.”

“Then what do you say, sir?” asked Frank.

Jack now added his voice to that of his chum, but for some moments Lord Hastings remained undecided. Frank, however, clinched the matter when he said:

“Well, there probably is no more danger that way than there is in trying to get out of here to the west, where every German submarine available is on the lookout for us.”

“Besides,” urged Jack, “they will watch the entrance to the Kiel canal less closely, because they would not dream of an attempt to force its passage.”

“There is some truth in that, too,” said Lord Hastings. “Well, the Kiel canal be it then.”

Both lads were jubilant, and they could not contain themselves, but expressed their delight with loud “hurrahs” and by tossing their caps in the air.

So it came to pass that the D-16 laid herself out on a course for the Kiel canal, the waterway which the Germans had constructed at such great expense, that her fleet in the North Sea and her fleet in the Baltic might ever be in touch with one another.

An attempted passage of the Kiel canal by a hostile ship or ships had been considered out of the question by all naval authorities. Such an attempt, it was claimed, would be too foolhardy and would be bound to end in destruction.

Nevertheless, Lord Hastings, while realizing all this, was not the man to turn from a purpose once he had made up his mind. He realized the full danger of the situation much more than did Frank or Jack, who, carried away by the opportunity of participating in what would be one of the greatest naval ventures of history, had at once lost sight of all possible danger.

Deep, deep down in the sea the D-16 made her way from the harbor of Heligoland, diving far beneath the mines that protected the German fortifications. And in her wake she left three sunken German ships of war and another so badly damaged that she would be out of commission for many months.

“I am willing to bet,” said Frank, “that the Germans either lay the raid to internal troubles or else claim that a British submarine flotilla of at least 20 vessels participated.”

“Right you are,” agreed Jack, “and they will probably add that the enemy was driven off with great loss, more than half their number being placed hors du combat.”

“At the same time,” interrupted Lord Hastings, “saying that ‘our losses were insignificant.’”

“Well,” said Frank, “I don’t suppose the government can afford to let the people know just how serious their predicament is.”

“That’s about the size of it,” agreed Lord Hastings.

The speed of the D-16, once she was beyond the German mine field, was increased to 20 knots, and she headed directly for the entrance to the Kiel canal. Frank and Jack both turned in.

With the coming of morning the D-16 was but a few miles from her goal, and Lord Hastings accordingly ordered the speed slackened that a close watch might be kept for mines.

At eight o’clock Lord Hastings checked the speed of the vessel and ordered that it be brought to the surface.

“But surely we are not through the canal yet?” protested Jack.

“No,” was the reply, “but we are almost at the entrance, and I want to take a look about.”

Jack did not protest further, and when the submarine again floated on the surface of the sea he followed his commander to the bridge.

There a startling sight met their gaze, for not a hundred yards away, riding gently with the even swell of the sea, lay a second submarine and she flew the Red, White and Black of Germany.

“Below quick!” cried Jack.

But Lord Hastings laid a hand on the lad’s arm as he darted for the hatchway.

“Wait a minute,” he said. “There doesn’t seem to be any one on guard, or we should have perceived some sign of life.”

The two peered long and earnestly at the German vessel, but not a sign of life could they make out.

“Must all be dead,” said Jack.

“Or asleep,” replied Lord Hastings.

“And that’s about what’s the matter,” agreed Jack. “What shall we do with the boat, sink her?”

“I suppose so,” replied Lord Hastings, “but I have another idea.”

“What is that, sir?”

“Well, forcing a passage of the Kiel canal is bound to prove ticklish work. Now if we could lay our hands on the officer of that vessel, we might persuade him to pilot us through.”

“A good idea,” said Jack, “if we could only get him.”

“We shall make a try at it,” said his commander.

“How?” asked Jack.

For answer Lord Hastings turned and went below, and in another moment the D-16 began creeping toward the German submarine.

At a distance of only a few yards she stopped and Lord Hastings motioned to Jack to follow him, as he dropped over the side into the little launch which had been lowered into the water. To Frank he called:

“If we do not reappear on deck within ten minutes, sink her.”

Frank indicated that he understood, and Lord Hastings and Jack put off for the enemy.

They clambered quietly aboard, and descended below without so much as being challenged. Just at the bottom of the companionway they came upon the figure of a man who emerged from one of the compartments. At sight of the British uniforms the man staggered back and his hand went to his side, but before he could draw a weapon, Jack had him covered with his own automatic and spoke quietly.

“One move and you are a dead man,” he said quietly.

“Who are you?” asked the man in a low voice.

“British officers,” said Lord Hastings. “And you?”

“Captain Bretog, commander of this vessel,” came the reply.

“Very good, captain,” said Lord Hastings. “You are our prisoner, and I must ask you to step upon the bridge.”

“How did you get here?” asked the German in surprise.

“In a little submarine of our own,” said Lord Hastings with a smile. “Come, now, captain.”

The captain moved toward the companionway, but just as he was about to go through the door, he turned and struck out at Lord Hastings. The latter dodged the blow and leaped quickly back, at the same time drawing his revolver.

“No more of that,” he said sternly. “Now move.”

But at that instant a German sailor appeared in sight. Perceiving the British uniforms, he cried out in surprise. An instant more and there came the sound of tramping feet, and half a dozen men tumbled into sight after him.

Lord Hastings put the German commander in front of him, and Jack stepped quickly to his commander’s side, their four automatics covering the superior numbers of the enemy.

“One move from any of you and you are all dead men,” said Lord Hastings calmly. “We’ll shoot you where you stand, and my vessel will blow you to atoms within half a minute.” He turned to the German commander.

“Captain,” he said, “order these men on deck ahead of you.”

The German made a move as though to refuse, but Jack’s revolver covered him and he did as commanded. The men, unarmed, filed up to the bridge.

“You next, captain,” said Lord Hastings, politely, stepping aside.

The German made a move as though to draw a revolver, and Jack was at his side in an instant.

“I’ll relieve you of your weapons,” he said quietly.

The German commander was forced to submit while the lad searched him and took his guns. Then, at another command from Lord Hastings, he followed his men on deck.

“Now,” said Lord Hastings, “you will instruct your men to lower that small boat and put off. Is this all your crew, sir?”

“Yes,” replied the German shortly.

“Good. For their sakes I hope you are telling the truth. For as soon as we are all safe, I intend to sink this vessel. Now order your men over the side.”

The German commander did as commanded, and soon the crew of the Teuton vessel were pulling away in the launch.

“Now, captain,” said Lord Hastings, “you will accompany me aboard my own ship.”

The German stepped into the D-16’s launch without a word, and the trio were soon aboard.

“Now,” said Lord Hastings, “if you wish, you shall have the pleasure of seeing me sink your vessel; or you may, if you would spare yourself that sight, go below.”

“I will go below if you please,” said the German.

Lord Hastings nodded his assent and Captain Bretog disappeared below as Lord Hastings turned to Jack.

“You may sink this German submarine immediately, Mr. Templeton,” he said quietly.

“Very good, sir,” replied Jack.

He saluted, turned on his heel and went below.

CHAPTER X.
IN THE KIEL CANAL.

Five minutes later and the D-16 was once more on her way, while behind her the ruins of a German submarine strewed the sea.

Immediately the D-16 had again submerged, Lord Hastings summoned Jack, Frank and the captured German officer to his quarters. Here, after motioning all to seats, he addressed the German commander.

“Captain,” he said quietly, “you are now aboard a British submarine that is about to attempt a passage of the Kiel canal.”

“What!” exclaimed the German officer, jumping to his feet. “It is impossible!”

“You are mistaken, sir,” replied Lord Hastings calmly. “With your help, I should say that it would be a matter of little moment.”

“With my help?” inquired the German officer.

“Exactly. You shall give us your assistance.”

“But, sir——” began the German.

Lord Hastings interrupted him with a wave of his hand.

“Protests will do no good,” he said quietly. “I take it that you are familiar with the locations of the mines and other danger points in and guarding the entrance to the canal. Am I right?”

The German officer bowed his head in assent.

“Then,” said Lord Hastings, “I fail to see why we should have much difficulty getting through.”

“You mean,” said the German slowly, “that you expect me to pilot your vessel through the canal?”

Lord Hastings bowed courteously.

“Exactly,” he replied.

The German officer drew himself up indignantly.

“That, sir,” he said, “is hardly a fair thing to ask of a prisoner.”

“Perhaps not, you being the prisoner,” replied the commander of the D-16. “Still, you may have heard that ‘All’s fair in love and war.’”

“And if I refuse?” said the German.

“Well, it’s hard to say,” replied Lord Hastings quietly. “But I can say this much: We cannot be burdened with any human excess.”

“You mean you will kill me?”

“Oh, no; nothing like that. Rather, I should suggest setting you adrift in a small boat.”

The German was silent for some moments, musing.

“And I might say,” continued Lord Hastings, “that you would be given no water or provisions.”

“You might just as well shoot me outright,” said the German.

Lord Hastings shrugged his shoulders.

“I couldn’t quite do that,” he replied.

“Well,” said the German officer, “if I must, I must, and that’s all there is about it.”

“I am glad you are so sensible,” said Lord Hastings. “Now, I shall turn the vessel over to you at once; but remember, at the first sign of treachery, there will always be a bullet waiting for you.”

The German bowed, but made no reply. Lord Hastings summoned a sailor, and instructed him to put the German officer in charge of the helm, but to keep close watch over him. The sailor and the German commander then left Lord Hastings’ quarters.

“Great Scott!” exclaimed Frank when they had gone. “Do you mean to tell me that you would have carried out your threat?”

“Well, hardly,” replied his commander with a laugh. “However, as you see, a threat in the proper place often works out advantageously.”

“Still,” said Jack, “I am not exactly satisfied that he means to play straight with us. He gave in too easily to suit me.”

“The same thought struck me,” declared Frank.

“Oh, I guess he’ll put us through,” said Lord Hastings.

“I’m not so sure,” from Frank skeptically.

“Well,” said Lord Hastings, “we’ll watch him carefully, and his first false step will be his last. We can’t afford to take chances now. One of us must be near him all the time.”

Thus it was arranged and Jack volunteered to take the first watch. Frank elected to take the second and Lord Hastings announced that he would take the third. This watch, it was agreed, would be maintained until they had passed through the canal.

Jack made his way at once to the helm, where he took up his station, while Frank and Lord Hastings turned in. Here the lad sat for four straight hours, not once relaxing his vigilance. Then Frank relieved him.

All went well in this second watch until there was but an hour of it left. Then the German commander turned to Frank.

“I’ll have to ask you to rise three fathoms,” he said.

“Rise?” said Frank. “What for?”

“Because,” was the reply, “the water is very shallow just ahead, and we shall run aground. We are now approaching the entrance to the canal.”

Frank looked at his captive long and searchingly. There was still a doubt of the German’s honesty of purpose in his mind, and for a moment he was undecided.

“We must rise at once,” said the German.

Frank made his decision quickly. “Very well,” he said quietly.

He stepped to the signal tube and gave the necessary order. A moment later the rising of the vessel became perceptible, as the water was slowly forced from her tanks.

Frank, not perfectly satisfied, however, stood facing the German officer, his hand on his revolver, determined to use it at the first sign of treachery.

But his uneasiness was without cause. When the submarine had risen the required distance, at a word from the German, her speed was increased and she moved forward again.

“Is there not danger of striking a mine up here?” asked Frank.

“There are a few about,” was the reply, “but I can guarantee that we shall not strike one. When the depth of the water permits, we shall go lower again.”

With this Frank was forced to be satisfied.

His four hours up, Frank was relieved by Lord Hastings, to whom he related what had occurred.

Lord Hastings listened quietly.

“I’m sure he will try no tricks,” he said. “However, I’ll keep an eye on him.”

“Still,” said Frank, “I have a premonition that all is not right.”

Lord Hastings laughed, and Frank retired.

Now the Kiel canal is not very long, sixty-one miles of water connecting the North and Baltic seas. It extends across the narrowest portion of Germany close to the boundary between Germany and Denmark, thus making a passage for German vessels from one sea to the other.

Lord Hastings had kept his own reckoning and believed, while he was not familiar with these waters, that he could determine when the Baltic end of the canal had been reached.

And, indeed, it seemed that he was right.

It was just after his watch, when Jack had relieved him and while he lingered in the compartment, that the German turned to Lord Hastings and said:

“You may rise now. You have done what it has been believed impossible for any hostile ship to do. You have passed through the Kiel canal.”

At that moment Frank, refreshed by a few hours’ sleep, entered.

As Lord Hastings was about to give the signal to rise, Frank stepped forward.

“One moment, sir,” he exclaimed. “Something tells me that all is not right. We had best be careful, sir.”

The German drew himself up.

“Do you mean to insinuate——” he began.

Jack silenced him with a word. Then he, too, turned to Lord Hastings.

“I can’t explain why, sir,” he said, “but I believe Frank is right. Also, you may remember, sir, how he has been right on more than one occasion and that you said hereafter you would place unusual confidence in his premonitions.”

“Bosh,” said Lord Hastings scornfully. “It is true I did say that, but this time there can be no mistake. I have kept the reckoning myself, and the German is right. By this time we should have reached the Baltic end of the canal.”

“But, sir,” protested Frank, “could he not have steered us the same distance, but in another direction? Is it not possible that when we come up we may be right in a nest of the enemy’s ships, or under the guns of their fortifications?”

“It is possible, yes,” replied Lord Hastings, “but you are wrong. You are both letting your imaginations run away with you. No; I am sure the man is up to no trick.”

“At least, sir,” protested Frank, “do not rise clear to the surface without looking about through the periscope.”

“That is good advice, and it shall be heeded,” said Lord Hastings. “Mr. Templeton, you may give the command to rise.”

Jack saluted and did as commanded, and with the periscope just above the water, the D-16 became stationary. Frank put his eye to the periscope and started back with an exclamation of dismay.

At the same moment the German officer sprang to the signal tube, and, in perfect English, gave the command to rise to the surface.

Jack took in the situation upon the instant and sprang toward the German even as he leaped toward the tube. But he was too late, and before he could countermand the order, the D-16 floated upon the surface of the water.

Jack, in the meantime, was grappling with the German officer, who had drawn a concealed revolver and was attempting to bring it to bear upon Lord Hastings. Frank sprang to his assistance, and Lord Hastings, unmindful of the struggle, and thinking only of the mistake he had made, stepped quickly from the compartment, and opening the conning tower, made his way to the bridge.

And there, he, too, started back in dismay, and no wonder. For what his eyes beheld was this:

Dead ahead rose the sheer walls of a massive fortress, the powerful guns of which swept the narrow canal for miles. And at either side, with the D-16 squarely between them, four battle cruisers rode gently on the waves.

Lord Hastings took one quick look at the flags that floated above the big battle cruisers, then dived hurriedly below.

For the flags that fluttered in the breeze were the flags of Germany!

CHAPTER XI.
AT CLOSE QUARTERS.

Below, Jack and Frank were still struggling with the German officer, but Lord Hastings had no time to lend them a hand. He raised his voice in a shout, and the crew came running at his command.

“Submerge instantly!” he cried.

But already sharp eyes aboard the German cruisers had caught sight of the submarine, and even as she sank suddenly from sight a single gun roared. The aim of this particular gunner was excellent; for the periscope of the D-16 was carried away as clean as a whistle.

Lord Hastings, who had been peering through it from below, was instantly aware of what had happened, and he immediately rushed to the compartment where the searchlight was placed and turned it on. This was now the only eye the submarine had with which to look for danger ahead.

Lord Hastings again raised his voice and a sailor came running to him. The commander of the vessel turned the lookout over to him and rushed to where he had left Frank and Jack.

When Frank had gone to his friend’s assistance, he had thought that together they would have little trouble overcoming the German officer. But the latter, in spite of Jack’s strength and all that Frank could do, was giving a good account of himself.

Blow after blow he landed upon each of the lads, but none had the power behind it to put them down. Time after time the two lads had closed in on him, only to be shaken off for the German was as slippery as an eel.

But finally Jack succeeded in gaining a strangle hold on the German, and putting forth his greatest strength, bore him to the floor, where both lads piled on top of him, pinioning his arms and legs. It was at this moment that Lord Hastings appeared upon the scene and rushed forward to lend a helping hand.

In falling the German’s head had come in violent contact with the floor, and he now lay still.

“Tie him up quickly,” commanded Lord Hastings. “We haven’t any time to waste on him.”

Jack and Frank hastened to obey, and soon the captive was securely bound.

The two lads noticed the signs of anxiety on their commander’s face and Frank asked:

“What’s the matter, sir?”

“Matter is that we are in a veritable nest of the enemy,” replied Lord Hastings. “Also our periscope has been shot away.”

“But we can rig up the other in no time,” said Jack.

“So we can,” said his commander, “but in the meantime they are likely to send a flotilla of submarines below to look for us.”

“Then we shall have to hustle,” said Frank.

“Hustle is the proper word,” agreed Lord Hastings. “Come with me.”

He led the way to the foot of the broken periscope, and quickly summoned several members of the crew. With all possible haste the second periscope, carried for just such an emergency, was brought out and run up.

“The only way we can tell whether it is adjusted properly,” said Lord Hastings, “is to rise, and that is exceedingly dangerous.”

“Well, we shall have to take a chance,” said Frank.

“So we shall,” was the reply. “You may give the order, Mr. Templeton.”

Jack did as commanded, and slowly the submarine began to rise. Lord Hastings stood at the foot of the second periscope, peering intently into it. At last he raised his hand in a sudden signal, and immediately the vessel began to sink again.

“It’s all right,” said the commander, turning to the lads. “I caught a glimpse of the surface.”

“Then we are all fixed again,” said Frank thankfully.

“Yes.”

“Then,” said Jack, “I should say the thing to do is to put as great distance as possible between us and the enemy.”

“The only draw back to that,” said Lord Hastings, “is that I do not know just where we are and to move in any direction is decidedly dangerous.”

“Weren’t you able to recognize the surroundings?” asked Frank.

“No; the canal is fortified all along, and all the fortifications look alike to me.”

“Well,” said Jack, “how about the prisoner? Don’t you think he can be made to pilot us out of danger?”

“No,” was the reply, “I don’t. I am absolutely positive he would refuse, no matter what the result. I am convinced that the only reason he agreed before was because he figured he could put us in the power of his friends. I don’t believe he scared worth a cent.”

“Nor I,” agreed Frank.

“Well, then what is to be done?” asked Jack.

“We shall just have to feel our way along carefully,” replied Lord Hastings. “But we must get away from this spot immediately. There is no telling what they may dump over on us. Straight ahead, Mr. Templeton, at seven knots.”

“Very good, sir,” replied the lad, and repeated the command to the engine room.

Lord Hastings himself took the helm, and Frank again stood watch in the forward compartment. For an hour they proceeded without incident, and then Lord Hastings decided to rise and take a look about.

Accordingly the pumps were set to work, and as the water was forced from the submersion tanks, the D-16 rose toward the surface. Lord Hastings, Frank and Jack ascended to the bridge.

“Well,” said the former, “we seem to have given them the slip.”

“It looks that way, sir,” replied Frank, after a quick glance over the water.

In the distance they could make out the forms of the battle cruisers, but evidently those aboard the German vessels did not perceive the submarine, lying low in the water.

Suddenly as the three stood talking, a figure bounded upon the bridge from below, and before any of the three could raise a hand to stop him, crossed the deck and hurled himself into the sea.

“Great Scott!” cried Frank. “It’s the German!”

“Impossible!” exclaimed Jack. “He was too securely bound to free himself.”

“But I am positive that is who it was,” said Frank.

All rushed to the side of the bridge, and peered intently into the water, waiting for the figure of the man to reappear upon the surface. Perhaps a minute later, they made out his form, quite a distance from the vessel, and swimming toward the distant German vessels with powerful strokes.

“Now I wonder how he managed to get——” began Jack, and paused suddenly.

For Frank, throwing off his coat, had hurled himself into the water and set out in pursuit of the fugitive.

“Here! Come back here!” called Jack to his friend.

Lord Hastings added his voice to Jack’s.

“Come back,” he cried. “Let him go.”

Frank waved one arm in the air and called back over his shoulder:

“I’ll get him. You wait right here for me if I am gone a year!”

Jack turned to Lord Hastings.

“Shall I jump over and bring him back?” he asked.

Lord Hastings shook his head.

“No,” he replied. “Let him go. If he can catch the German, all right; but I doubt it. However, when he finds that the chase is hopeless and that he is likely to fall into the hands of the enemy, he will turn back.”

“I’m not so sure about that,” said Jack. “Frank is rather hot headed at times, you know, and he is likely to chase him clear aboard a German warship.”

“I give him credit for more sense than that,” said Lord Hastings.

“So do I,” said Jack, “at times. At other times he loses his head altogether.”

“Well, the best thing we can do is to wait and see what happens,” said Lord Hastings. “The only thing that worries me is that the German may prove more than a match for him should he overtake him.”

“I’ll leave it to Frank to get himself out of any trouble like that,” said Jack. “The only thing that I am afraid of is his hot-headedness.”

In the meantime, exert himself as he would, Frank realized that he was not lessening the distance between himself and the fugitive; but the lad was not one to give up the chase so easily. He gritted his teeth and muttered to himself:

“I’ll get him if I have to chase him all around the world.”

After a time Frank’s hopes arose, for a quick look ahead showed him that he had gained a trifle. This encouraging sign lent strength to his arms. He struck out more vigorously than before, as he realized that it was only a question of time until he overtook his quarry.

But what the lad did not know was that at that very instant the lookout on the nearest German warship had caught sight of the two swimmers. A shouted command aboard the German vessel, and a launch put off over the side and dashed rapidly toward the German officer in the water.

This Frank did not see, and so swam on in ignorance of the danger that threatened. Raising his eyes, a couple of minutes later he saw the German officer as he was picked up by the boat, and for the first time realized that he was in a ticklish situation.

“Great Scott!” he muttered to himself. “Why didn’t I keep my eyes open? I hope they are satisfied with saving him and let me alone.”

He turned quickly, and made for the D-16 as fast as he could swim.

But his hopes were to prove fruitless, as a quick glance over his shoulder told him. In the launch he perceived the German commander gesticulating violently and pointing in his direction.

“I guess it’s up to me to hustle,” he told himself.

Now the German launch started after him, gaining at every stroke the lad made.

Lord Hastings and Jack perceived the turn of affairs, and Jack cried out:

“Get the launch over quick and man it. Unless we can lick these fellows, Frank is a goner.”

The crew acted with promptness, and in a twinkling the launch of the D-16 also was racing toward the swimming lad.

CHAPTER XII.
CAPTURED.

Frank, literally the bone of contention between the two forces in the launches, swam as swiftly as possible in the direction of safety; but the furtive glances he cast over his shoulder showed him that the Germans were nearer than his friends, and that in spite of the fact that he was swimming toward the latter, the former would come up with him first.

The men in both boats were now on their feet, and their revolvers spoke across the water. As yet, however, they were too far away to make accurate shooting possible, and no one was even touched.

But soon the German boat drew so close to Frank, that the men in the D-16’s launch were afraid to fire at the Germans for fear a chance shot might hit the lad. The Germans, however, were not thus handicapped, and continued pouring lead in the direction of Lord Hastings and his men.

As the German boat came alongside Frank, a man reached out to grab him. Frank took a long breath and dived, the fingers of his foe just touching his shoulder.

When he came to the surface for a fresh breath, the German boat was several yards away and Frank breathed easier.

“If I can keep that up,” he told himself, “I may get away yet.”

Again the boat drew near and again Frank dived.

The German officer in command had had enough of this game of hide and seek, however, and he immediately ordered two of his men overboard after the lad.

Frank, of course, knew nothing of this move and when he came to the surface once more, he was surprised to find rough hands laid upon him from both sides. In vain did he strike out with both feet and hands. Struggle as he would he could not shake off his foes; and all three sank together.

The German boat came closer, and the sailors leaned over the side, ready to pull in the struggling trio when they came to the surface again.

Sputtering and gasping for breath, the three heads finally showed above the water. There was not much fight left in any of them, and therefore Frank was drawn over the side without much trouble. Then the German officer ordered the launch brought about, and put off for the German cruiser at full speed.

As they fled, a running battle with the men in the D-16’s launch ensued. One German toppled over into the water, but the boat was not stopped to pick him up. One British sailor was struck in the arm by a German bullet; but outside of these two no one was wounded.

The German launch had the heels of the D-16’s small boat, and soon outdistanced her. Convinced at last that pursuit was useless, Lord Hastings ordered that the chase be abandoned. The launch was brought about and headed slowly back toward the submarine.

“Poor Frank,” said Jack. “I always knew his rashness would get him in trouble some day. I am afraid his days of fighting are over.”

“While there is life there is hope,” said Lord Hastings calmly. “Perhaps we may be able to figure out some means of rescue.”

“A great chance,” said Jack sarcastically. “Right in the heart of the enemy’s country? I don’t think so. What do you suppose they will do with him?”

“Hold him as a prisoner of war.”

“Then there is no danger of his being shot?”

“I should say not.”

“Well, that’s not so bad. Still, it is pretty tough for him to be cooped up for the next few years.”

Aboard the D-16 once more, all went below immediately and Lord Hastings gave the command to submerge.

“They know we are here now,” he said, “and they’ll be after us. Therefore we had better get down. We’ll stay around for a while and see if we cannot be of some help to Frank. We may be able to maneuver so as to avoid detection.”

“When it comes to that,” said Jack, “we might as well be here as any place else. I should say that there is considerable work we could do hereabouts, and if we can avoid the enemy we can make it pretty warm for them.”

“You are right,” replied Lord Hastings, “but we shall have to be very careful, for, knowing we are here, they will undoubtedly have every ship in these waters looking for us.”

“Well,” said Jack, “why should we wait for them to act? Why can’t we strike the first blow?”

Lord Hastings looked at him quizzically.

“Just what do you mean by that?” he asked.

“Why,” said Jack, “torpedo one of them right now.”

“I am afraid you are a little hot headed yourself,” said his commander with a faint smile. “I should say that that is just what they expect us to do, and for that reason I am opposed to such action. Never do the expected, is my motto. It is the unexpected that counts.”

“Perhaps you are right,” agreed Jack; “still I would like to get at a few of them.”

“Don’t fret,” said Lord Hastings, “you shall have your chance.”

Meanwhile, what of Frank?

Immediately the launch had returned to the German cruiser, the lad was hurried over the side and taken to the commander’s cabin. The latter received him courteously and motioned him to a seat.

“And how, if I may ask,” he inquired, “do you happen to be in the middle of the Kiel canal?”

Frank smiled slightly.

“I came in a submarine,” he replied.

“So I have perceived,” said the commander.

“But I was unaware England had established a submarine base anywhere near German territory.”

“Neither has she, to my knowledge,” said Frank.

“Then how did you get here? Surely you must have a base.”

“Our base,” said Frank, “was London.”

“What?” exclaimed the German, jumping to his feet. “You sit here and tell me a thing like that? Surely you can’t think I don’t know that a submarine cannot operate that distance from her base.”

“Nevertheless, it is true,” replied Frank quietly.

“But your air supply, your torpedoes, your provisions,” exclaimed the German commander.

“Those we carry with us,” said Frank.

“Then,” said the German sarcastically, “yours must be a very remarkable submarine.”

“So it is,” replied Frank.

“Well, it will be impossible for her to get away,” said the German. “We have her bottled up, and all we need do is wait until she comes to the surface to replenish her air tanks; then we can sink her.”

“You’ll have a long wait,” said Frank. “She doesn’t have to come up for that purpose.”

“What do you mean by that?”

“Just what I say. The submarine to which I am attached carries no air tanks except those to be used in case of an emergency.”

“No air tanks! Then how do you get air?”

“Well,” said Frank, “I can’t see that it will do any harm to tell you. We extract air from the water.”

The German commander leaned back in his chair and looked at the lad in amazement.

“Extract air from the water, eh?” he said slowly. “Do you mean to tell me that England has solved that problem?”

“She has, sir,” replied Frank quietly.

The German was silent for a long time before he said: “Then I must say that Germany has a hard job on her hands.”

Frank was silent and the captain continued:

“And how many such vessels have you in operation?”

Frank hesitated.

“Well, only a few right now,” he said at last. “But many more are in the process of construction.”

“And are you familiar with the operations of such a vessel, and of the method used?”

“To a certain extent, yes.”

“But I do not suppose you could be prevailed upon to divulge the secret?”

“I could not,” replied Frank quietly.

“Good! I thought not. Well, it’s too bad that we were not the first to discover the secret; but you will find that we do not whine, nor will we seek to obtain the secret by unfair means.”

“I am sure of it, sir,” replied Frank.

“Now,” said the German commander, “I must decide what I am going to do with you. I suppose that you know you will be held until the end of the war?”

Frank nodded as he replied: “I should suppose so.”

“I shall have you sent ashore in the morning and turned over to the military authorities. The chances are that you will be taken to Berlin. Of that I am not sure, however.”

“One place will do as well as another, I suppose.”

“I’m glad you are cheerful about it,” laughed the captain, “and as mess hour is approaching I shall be glad to have you dine with me.”

“I shall be pleased to do so, sir.”

“By the way,” said the German, “what is the speed of this remarkable submarine of yours?”

“I wouldn’t like to say,” replied Frank, “but I can say that it is fully as great as that of your fastest battleship.”

The German puckered his lips in a long expressive whistle.

“Well,” he said, “it’s too bad for us. Now, if you care to wash up I shall have you shown to your temporary quarters.”

It was a pleasant meal to which the lad sat down that evening, and he enjoyed himself immensely. He found the German officers a likeable lot and was treated more as a guest than as a prisoner.

It was while at table that he learned that German submarines had been sent down in search of the British vessel, and that each battleship was being guarded by an under-the-sea fighter so that no surprise attack by the D-16 might be made.

At a late hour the lad retired and slept the sleep of the exhausted.

He was up bright and early the following morning, and after breakfast took his place in the ship’s launch, which immediately headed toward the shore. The captain bade him a pleasant good-bye, and added:

“If I get to Berlin I shall look you up.”

“I’m not there yet,” said Frank, but in his heart he was pretty sure that it was only a question of hours until he would be.

CHAPTER XIII.
A SUBMARINE RAID.

Creeping stealthily forward beneath the water, the D-16 was advancing to the attack. Lord Hastings stood at the periscope and Jack was at his elbow. The vessel was prepared for action, and the crew stood at attention.

Lord Hastings touched Jack on the shoulder.

“Tell the watch to keep a sharp lookout for submarines,” he said. “The chances are that they have been thrown out in front of the battleships.”

Jack departed and gave the necessary order, after which he returned to his position.

It was just after dusk on the evening following the day on which Frank had been captured. All day and all during the previous night the D-16 had kept near the bottom, maneuvering first this way and then that, and not once had they caught sight of an enemy’s submarine, nor had they risen to the surface for a look about.

But now Lord Hastings had decided upon action. He had idled long enough. Therefore, after preparing for action, the D-16 had risen sufficiently to give her periscope free play, and the commander now gazed over the water.

“German battleship ahead,” he called to Jack. “Slow to five knots.”

The speed of the submarine slackened.

“Take the lookout yourself, Mr. Templeton,” was the next command.

Jack did as commanded, and peered intently ahead. In the dark murky water he could see but a few feet, for it had not been deemed advisable to turn on the searchlight and thus make a target for the enemy’s submarines.

However, the D-16 was progressing at a snail’s pace and could be halted upon the instant. Therefore, there was not much danger of encountering any obstacle, providing the man on lookout attended to his duties properly.

Suddenly a dark object loomed up ahead. Quick as a flash Jack signalled the engine room and the D-16 came to an abrupt stop. Jack reported to Lord Hastings.

“Dark object right ahead that looks like a submarine submerged,” he said calmly.

“Give the order to back away a hundred yards, then fire a torpedo into her,” was Lord Hastings’ command.

Slowly the D-16 backed away from the dark object ahead, and an instant later a sharp “click” gave evidence that a torpedo had been launched. Immediately Jack flashed on the searchlight.

While his eyes could not follow the flight of the torpedo, the huge and powerful searchlight showed him the result. Struck squarely amidships the German submarine, for such the object ahead proved to be, seemed to split wide open. The water poured in in a dense volume, and suddenly the enemy sank.

Jack shuddered.

“Must be a terrible death,” he muttered to himself. “However, if we had not sunk her she would probably have sunk us.”

Once more he reported to Lord Hastings.

“Way clear now, sir,” he said.

“Good,” was the reply. “Make your speed five knots and continue your course.”

Perhaps ten minutes more and then Lord Hastings gave the command to heave to. For, through the periscope, less than a quarter of a mile away, he could make out the form of a giant German battle cruiser, a trifle to starboard.

The electric signal board flashed its message of death:

“No. 5 torpedo!”

“Ready!”

“Fire!”

“Click!”

Just this little sound and then Lord Hastings gave the command to rise, for he wished to witness the effect of the torpedo on the German cruiser.

The D-16 rose swiftly, but not as swiftly as the torpedo had sped on its way. For when the submarine reached the surface the torpedo had already done its work, and the German cruiser was helpless. Men were jumping into the sea on all sides and swimming away.

Jack was struck with a sudden idea. He turned to Lord Hastings.

“If we could pick up one of those fellows,” he said, pointing, “perhaps we could find out what has happened to Frank.”

“Good,” replied Lord Hastings, “it shall be done.”

Upon his command the submarine forged ahead slowly directly toward the doomed German cruiser. Heads of men swimming began to bob up and down on both sides. Jack, leaning over the side, which was almost level with the water, suddenly stretched forth a hand and dragged a German petty officer aboard.

Frightened almost out of his wits, for he had not perceived the dark outline of the submarine, the German struggled fiercely; but he was no match for Jack, who soon subdued him.

The man was dragged below, and upon Jack’s request, the submarine was again submerged.

When the prisoner learned that he was aboard the British submarine he braced up, and when he found that he was not to be harmed, he proved willing to talk.

“Where is the English prisoner whom you captured yesterday?” Lord Hastings asked him.

“He has been sent ashore,” was the reply. “He was to have been taken to Berlin today, to be held as a prisoner of war; but I understand that for some reason it was put off till tomorrow.”