"Yes—right!" said Runnells mechanically again—and stumbled, half running, across the room and out of the door.

Captain Francis Newcombe flung himself into the chair Runnells had vacated. His mind was on Paul Cremarre now. What was it that had caused the man's death? As Runnells had said, it was a sickening sight. Well, no matter! The mode or cause of death was an incident, wasn't it? Paul Cremarre found here on the island, whether dead or alive, was what mattered—it meant that the menace, that hellish nightmare of the "unknown," that had been hanging over him, Shadow Varne, was gone now—that the way was clear ahead—a fortune here—America once more an "open sesame"—riches, luxury, all he had builded for, his again to take at his leisure without fear now of any interference from any source. And yet he seemed to hate the man the more because he was dead. Cremarre had done what no other man had ever done to Shadow Varne—those black hours—last night—the night before.

His hands clenched fiercely. He knew a sudden, unbridled rush of anger directed against the agency, be it what it might, that had caused Paul Cremarre's death—that had forever removed the man beyond his reach, and had robbed him of a right that alone was his to settle with the man. He had owed the other a debt that he could never now repay—the sort of debt that Shadow Varne, until now, had never failed to pay. It was all clear enough now. Paul Cremarre, if not from the moment he had read Polly's letter that morning in London, had finally at any rate yielded to the temptation that the opportunity of securing so great a sum of money had dangled before his eyes. Cremarre, like Runnells, had very possibly, and perhaps not unwarrantably, been sceptical about his, Captain Francis Newcombe's, statement that the money here was to be held inviolable; but whether he had or not made very little difference in the last analysis, for, either way, it would be obvious to Paul Cremarre that he would get none of the money unless he got it through his own secret endeavours, since, even if he, Captain Francis Newcombe, were after it for himself, Cremarre would realise that he was not to share in the spoils.

It was quite plain! It was Paul Cremarre who had fired that shot through the cabin window in the storm on the liner that night in order to possess for himself a free hand on the island here. The man, in disguise of course, had sailed on the same ship—because he would not have dared to have left London before he, Newcombe, left, for fear of arousing suspicions, since he was known to be acquainted with the contents of the letter; and he would not have dared risk a later vessel for fear of arriving too late and only to find the money gone should he, Newcombe, prove to be after it for himself. It was Paul Cremarre here on the island who had on those three occasions, ending with to-night, sought through the medium of fear, no, more than that, through an appeal to the impulse for self-preservation, to drive him, Newcombe, away—and leave Paul Cremarre in sole possession of the field. And it was quite plain now, too, why the man had not, here on the island, attempted murder again as he had done on the liner. It was not that the chances of discovery were less on board the ship; but that here a murder would cause an invasion of the island by police and detectives which would automatically hamper Cremarre in his efforts to find the money, if, indeed, it would not force him to leave the island entirely in order to make his own escape.

Captain Francis Newcombe's hand was groping tentatively in his pocket now. It was not at all unnatural that the thought of Paul Cremarre had not entered his head. To begin with, he had trusted the hound; and, again, he had sailed immediately on the first ship after leaving the man in London. But now! Yes, that was where the crux of the whole thing lay—the time spent on that yachting trip of Locke's down the coast. Paul Cremarre had probably been on the island for several days before the Talofa arrived, and—

His hand came out of his pocket. In its palm lay the bronze key. He stared at it thoughtfully. No, Paul Cremarre had not succeeded in getting the madman's money prior to to-night, for in that case old Marlin would have discovered his loss and raised a wild fuss; and, besides, if successful, Cremarre would have left the island without loss of time. Nor had Cremarre been quite successful to-night, for the money was not on his person; but he had been—what? Captain Francis Newcombe stared for another long minute at the bronze key, then jumping suddenly up from the chair, he crossed over to the table and began to divest his pockets of the articles he had taken from Paul Cremarre. He tumbled them out on the table: A roll of bills; a passport—made out under an assumed name—to one André Belisle; a few papers such as railroad folders, a small map of the Florida Keys, some descriptive matter pertaining thereto, and among these a little book.

Captain Francis Newcombe snatched up the book—and suddenly he began to laugh, a strange laugh, hoarse with elation, a laugh that even found expression in the quick, triumphant glitter in his eyes. Several times in the short period during which he had been here on the island he had seen this little book, and more than once he had endeavoured unostentatiously to obtain a closer look at it, but without success. It was the old madman's little book—the little buff-coloured, paper-covered little book that the old fool, he had noticed, would frequently pull out of his pocket and consult for no reason apparently other than that it had become a habit with him. It was a common book, a very common book—an innocent book. Its title was on the cover. It was a book of tide tables.

And again and again now Captain Francis Newcombe laughed. The bronze key and the book of tide tables! The pieces of the puzzle aligned themselves of their own accord into a complete whole. An hour later every night! The old madman went out an hour later every night. So did the tide! Those footprints there under the boathouse—not Paul Cremarre's, the other ones! The succession of nights during which the old maniac went out until the hour just before daybreak was reached—and then the period of inaction. At low water, like to-night, eh? Yes, yes! He did not go out when the tide was low too early in the evening or too late in the morning; in the former case for fear of being seen, in the latter because it would be full daylight before the tide would creep in to wash away the tell-tale footprints. Paul Cremarre's presence there—his footmarks leading away from the water to the spot where he had collapsed and died! Cremarre with a bronze key in his hand, and the old maniac's book of tide tables—Cremarre had made an attempt to get the money after the old man had been there, and something, God knew what, had done him down instead. It must have been subsequent to the old man's visit, for Marlin was now in his room—he, Captain Francis Newcombe, had listened at the fool's door when he had returned long after three o'clock from that trip to the old hut in the woods—and three o'clock was past the hour of low water, and old Marlin had appeared to be quietly asleep, which under no circumstances would he have been had he been conscious of the loss of his key and book. There were a dozen theories that would logically reconstruct the scene—but none of them mattered. It was the existing fact that mattered. Cremarre, hidden himself, might, and very probably had, watched the old maniac at work; afterwards, whether the old man had lost the key and book from the pocket of his dressing gown as it flapped around him and Cremarre had found them, or Paul Cremarre, than whom there was no craftier thief in Christendom, had succeeded in purloining them, again mattered not a whit. What mattered was that there was only one place now where the old maniac's secret depository could be—only one. And he, Captain Francis Newcombe, now knew where that one place was.

And yet again he laughed—loud in his evil joy, vauntingly in his triumph. It was his now! There was no longer anything to mar his plans. Nemesis was dead! No haunting thing to strike any more out of the darkness and drive him back, with bared teeth, against the wall, to make of him little better than a cornered rat. Why shouldn't he laugh now—at man, or devil, or Heaven, or hell! He was master—as Shadow Varne had always been master. He tossed the bronze key up in the air and caught it again with deft, yet savage grasp. The hiding place was found. There was only a keyhole to look for now. A keyhole ... a keyhole.... Mad mirth caught up the words and flung them in jocular song hither and thither within his brain. A keyhole ... a keyhole....

"You'd raise your cursed voice to bawl at Shadow Varne, would you, Paul Cremarre?" he cried. "Well, damn you—thanks!"