Vance hastened back down the cement walk toward the pool, with the rest of us close behind him, not knowing where he was leading us and with only a vague idea of his object. But there was something in his tone, as well as in his dynamic action, which had taken a swift and strong hold on all of us. I believe that Markham and Heath, like myself, felt that the end of this terrible case was near, and that Vance, through some subtle contact with the truth, had found the road which led to its culmination.

    Half-way down the walk Vance turned into the shrubbery at the right, motioning us to follow.

    "Be careful to keep out of sight of the house," he called over his shoulder, as he headed for the vault.

    When he had reached the great iron door he looked about him carefully, glanced up at the high cliff, and then, with a swift movement to his pocket, took out the vault key. Unlocking the door, he pushed it inward slowly to avoid, I surmised, any unnecessary noise. For the second time that day we entered the dank close atmosphere of the old Stamm tomb, and Vance carefully closed the door. The beam from Heath's flashlight split the darkness, and Vance took the light from the Sergeant's hand.

    "I'll need that for a moment," he explained, and stepped toward the grim tier of coffins on the right.

    Slowly Vance moved the light along those gruesome rows of boxes, with their corroded bronze fittings and clouded silver name-plates. He worked systematically, rubbing off the tarnish of the silver with his free hand, so that he might read the inscriptions. When he had come to the bottom tier he paused before a particularly old oak coffin and bent down.

    "Slyvanus Anthony Stamm, 1790-1871," he read aloud. He ran the light along the top of the coffin and touched it at several points with his fingers. "This should be the one, I think," he murmured. "There's very little dust on it, and it's the oldest coffin here. Disintegration of the body will be far advanced and the bone structure will have crumbled, leaving more room for—other things." He turned to Heath. "Sergeant, will you and Snitkin get this coffin out on the floor. I'd like a peep in it."

    Markham, who had stood at one side in the shadows watching Vance intently and doubtfully, came quickly forward.

    "You can't do that, Vance!" he protested. "You can't break into a private coffin this way. You can be held legally accountable. . . ."

    "This is no time for technicalities, Markham," Vance returned in a bitter, imperious voice. . . . "Come, Sergeant. Are you with me?"

    Heath stepped forward without hesitation. "I'm with you, sir," he said resolutely. "I think I know what we're going to find."

    Markham looked squarely at Vance a moment; then moved aside and turned his back. Knowing what this unspoken acquiescence on Markham's part meant to a man of his precise and conventional nature, I felt a great wave of admiration for him.

    The coffin was moved from its rack to the floor of the vault, and Vance bent over the lid.

    "Ah! The screws are gone." He took hold of the lid, and with but little effort it slid aside.

    With the Sergeant's help the heavy top was removed. Beneath was the inner casket. The lid of this was also loose, and Vance easily lifted it off and placed it on the floor. Then he played the flashlight on the interior of the casket.

    At first I thought the thing I saw was some unearthly creature with a huge head and a tapering body, like some illustrations I had seen of Martians. I drew in an involuntary, audible breath: I was shocked and, at the same time, frightened. More monsters! My one instinct was to rush out into the clean sunlight, away from such a hideous and terrifying sight.

    "That's a duplicate of the suit I saw today, Markham," came Vance's steadying, matter-of-fact voice. He played his light down upon it. "A shallow-water diving suit—the kind used largely in pearl-fishing. There's the three-light screw helmet with its hinged face-plate. . . . And there's the one-piece United States Navy diving dress of rubberized canvas." He bent over and touched the gray material. "Yes, yes, of course—cut down the front. That was for getting out of it quickly without unscrewing the helmet and unlacing the backs of the legs." He reached into the casket alongside the diving suit and drew forth two rubber gloves and a pair of brass-soled shoes. "And here are duplicates of the shoes and gloves I brought here with me." (They were both caked with dried mud.) "These are what made the dragon's imprints on the bottom of the pool."

    Markham was gazing down into the casket, like a man stunned by a sudden and awe-inspiring revelation.

    "And hidden in that coffin!" he muttered, as if to himself.

    "Apparently the one safe place on the estate," Vance nodded. "And this particular coffin was chosen because of its age. There would be little more than bones left, after all these years; and with a slight pressure the frame of the chest walls would have caved in, making space for the safe disposal of this outfit." Vance paused a moment, and then went on: "This type of suit, d' ye see, doesn't require an air pump and hose connection. An oxygen tank can be clamped to the breast-plate and attached to the intake-valve of the helmet. . . . See this?"

    He pointed to the foot of the casket, and I saw, for the first time, lying on the bottom, a metal cylinder about eighteen inches long.

    "That's the tank. It can be placed horizontally across the breast-plate, without interfering with the operations of the diver."

    As he started to lift out the oxygen tank we heard a clinking sound, as if the tank had come in contact with another piece of metal.

    Vance's face became suddenly animated.

    "Ah! I wonder. . . ."

    He moved the tank to one side and reached down into the depths of that ancient coffin. When his hand came out he was holding a vicious-looking grappling-iron. It was fully two feet long and at one end were three sharp steel hooks. For a moment I did not grasp the significance of this discovery; but when Vance touched the prongs with his finger I saw that they were clotted with blood, and the horrible truth swept over me.

    Holding the grappling-iron toward Markham, he said in a curiously hushed voice:

    "The dragon's claws—the same that tore Montague's breast—and Greeff's."

    Markham's fascinated eyes clung to the deadly instrument.

    "Still—I don't quite see—"

    "This grapnel was the one missing factor in the hideous problem," Vance interrupted. "Not that it would have mattered greatly, once we had found the diving suit and had explained the imprints in the pool. But it does clarify the situation, don't y' know."

    He tossed the iron back into the casket and replaced the cover. At a sign from him Heath and Snitkin lifted the heavy oak lid back to the coffin and returned the ancient box, with its terrible and revelatory contents, to its original position on the lower tier.

    "We're through here—for the present, at any rate," Vance said, as we passed out into the sunlight. He locked the door of the vault and dropped the key back into his pocket. "We had better be returning to the house, now that we have the solution to the crimes. . . ."

    He paused to light a cigarette; then looked grimly at the District Attorney.

    "Y' see, Markham," he said, "there was, after all, a dragon involved in the case—a fiendish and resourceful dragon. He had vengeance and hate and ruthlessness in his heart. He could live under water, and he had talons of steel with which to tear his victims. But, above all, he had the shrewd calculating mind of man—and when the mind of man becomes perverted and cruel it is more vicious than that of any other creature on earth."

    Markham nodded thoughtfully.

    "I'm beginning to understand. But there are too many things that need explaining."

    "I think I can explain them all," Vance replied, "now that the basic pattern is complete."

    Heath was scowling deeply, watching Vance with a look which combined skepticism with admiration.

    "Well, if you don't mind, Mr. Vance," he said apologetically, "I'd like you to explain one thing to me right now.—How did the fellow in the diving suit get out of the pool without leaving footprints? You're not going to tell me he had wings, too, are you?"

    "No, Sergeant." Vance waved his hand toward the pile of lumber beside the vault. "There's the answer. The point bothered me too until this afternoon; but knowing he could have left the pool only by walking, I realized that there must inevitably be a simple and rational explanation for the absence of footprints—especially when I knew that he was weighted down and wearing heavy diving shoes. When I approached the vault a few minutes ago, the truth suddenly dawned on me." He smiled faintly. "We should have seen it long ago, for we ourselves demonstrated the method by doing exactly the same thing when we walked out over the bottom of the pool. The murderer placed one of these boards between the end of the cement walk and the edge of the pool,—the width of that stretch of flat ground is little more than the length of the timber. Then, when he had walked out of the pool over the board, he simply carried it back and threw it on the pile of lumber from which he had taken it."

    "Sure!" Heath agreed with a kind of shamefaced satisfaction. "That's what made that mark on the grass that looked like a heavy suit-case had been set there."

    "Quite right," nodded Vance. "It was merely the indentation made by one end of the heavy plank when the chappie in the diving suit stepped on it. . . ."

    Markham, who had been listening closely, interrupted.

    "The technical details of the crime are all very well, Vance, but what of the person who perpetrated these hideous acts? We should make some definite move immediately."

    Vance looked up at him sadly and shook his head.

    "No, no—not immediately, Markham," he said. "The thing is too obscure and complicated. There are too many unresolved factors in it—too many things to be considered. We have caught no one red-handed; and we must, therefore, avoid precipitancy in making an arrest. Otherwise, our entire case will collapse. It's one thing to know who the culprit is and how the crimes were committed, but it's quite another thing to prove the culprit's guilt."

    "How do you suggest that we go about it?"

    Vance thought a moment before answering. Then he said:

    "It's a delicate matter. Perhaps it would be wise to make subtle suggestions and bold innuendos that may bring forth the very admission that we need. But certainly we must not take any direct action too quickly. We must discuss the situation before making a decision. We have hours ahead of us till nightfall." He glanced at his watch. "We had better be going back to the house. We can settle the matter there and decide on the best course to pursue."

    Markham acquiesced with a nod, and we set off through the shrubbery toward the car.

    As we came out into the East Road a car drove up from the direction of Spuyten Duyvil, and Stamm and two other men who looked like workers got out and approached us.

    "Anything new?" Stamm asked. And then, without waiting for an answer, he said: "I'm going down to get that rock out of the pool."

    "We have some news for you," Vance said, "—but not here. When you've finished the job," he suggested, "come up to the house. We'll be there."

    Stamm lifted his eyebrows slightly.

    "Oh, all right. It'll take me only an hour or so." And he turned and disappeared down the cement path, the two workmen following him.

    We drove quickly to the house. Vance, instead of entering at the front door, walked directly round the north side of the house, to the terrace overlooking the pool.

    Leland was seated in a large wicker chair, smoking placidly and gazing out at the cliffs opposite. He barely greeted us as we came forward, and Vance, pausing only to light a fresh cigarette, sat down beside him.

    "The game's up, Leland," he said in a tone which, for all its casualness, was both firm and grim. "We know the truth."

    Leland's expression did not change.

    "What truth?" he asked, almost as if he felt no curiosity about the matter.

    "The truth about the murders of Montague and Greeff."

    "I rather suspected you would find it out," he returned calmly. (I was amazed at the man's self-control.) "I saw you down at the pool a while ago. I imagine I know what you were doing there. . . . You have visited the vault also?"

    "Yes," Vance admitted. "We inspected the coffin of Sylvanus Anthony Stamm. We found the diving equipment in it—and the three-pronged grappling-iron."

    "And the oxygen tank?" Leland asked, without shifting his eyes from the cliffs beyond.

    Vance nodded.

    "Yes, the tank too.—The whole procedure is quite clear now. Everything about the crimes, I believe, is explained."

    Leland bowed his head, and with trembling fingers attempted to repack his pipe.

    "In a way, I am glad," he said, in a very low voice. "Perhaps it is better—for every one."

    Vance regarded the man with a look closely akin to pity.

    "There's one thing I don't entirely understand, Mr. Leland," he said at length. "Why did you telephone the Homicide Bureau after Montague's disappearance? You only planted the seed of suspicion of foul play, when the episode might have passed as an accident."

    Leland turned his head slowly, frowned, and appeared to weigh the question that Vance had put to him. Finally he shook his head despondently.

    "I do not know—exactly—why I did that," he replied.

    Vance's penetrating eyes held the man's gaze for a brief space of time. Then he asked:

    "What are you going to do about it, Mr. Leland?"

    Leland glanced down at his pipe, fumbled with it for a moment, and then rose.

    "I think I had better go up-stairs to Miss Stamm—if you don't mind. It might be best if it were I who told her." Vance nodded. "I believe you are right."

    Leland had scarcely entered the house and closed the door when Markham sprang to his feet and started after him; but Vance stepped up quickly and put a firm restraining hand on the District Attorney's shoulder.

    "Stay here, Markham," he said, with grim and commanding insistence.

    "But you can't do this thing, Vance!" Markham protested, trying to throw off the other's hold. "You have no right to contravene justice this way. You've done it before—and it was outrageous!"[17]

    "Please believe me, Markham," Vance returned sternly, "it's the best thing." Then his eyes opened wide, and a look of astonishment came into them. "Oh, my word!" he said. "You don't yet understand. . . . Wait—wait." And he forced Markham back into his chair.

    A moment later Stamm, in his bathing suit, emerged from one of the cabañas and crossed the coping of the filter to the windlass beyond. The two men he had brought with him from Spuyten Duyvil had already attached the rope to the drum and stood at the hand-cranks, awaiting Stamm's orders. Stamm picked up the loose end of the coiled rope and, throwing it over his shoulder, waded into the shallow water along the foot of the cliff until he came to the submerged rock. We watched him for some time looping the rope over the rock and endeavoring to dislodge it with the assistance of the men operating the winch. Twice the rope slipped, and once a stake anchoring the winch was dislodged.

    It was while the men were repairing this stake that Leland returned softly to the terrace and sat down again beside Vance. His face was pale and set, and a great sadness had come into his eyes. Markham, who had started slightly when Leland appeared, now sat looking at him curiously. Leland's eyes moved indifferently toward the pool where Stamm was struggling with the heavy rope.

    "Bernice has suspected the truth all along," Leland remarked to Vance, in a voice barely above a whisper. . . . "I think, though," he added, "she feels better, now that you gentlemen understand everything. . . . She is very brave. . . ."

    Across the sinister waters of the Dragon Pool, there came to us a curious rumbling and crackling sound, like sharp, distant thunder. As I instinctively glanced toward the cliffs I saw the entire pinnacle of the rocky projection we had examined the day before, topple and slide downward toward the spot where Stamm was standing breast-deep in the water.

    The whole terrible episode happened so quickly that the details of it are, even today, somewhat confused in my mind. But as the great mass of rock slid down the cliff, a shower of small stones in its wake, I caught a fleeting picture of Stamm glancing upward and then striving frantically to get out of the path of the crashing boulder, which the rainstorm earlier in the afternoon must have loosened. But his arms had become entangled in the rope which he was attempting to fasten about the rock in the pool, and he was unable to disengage himself. I got a momentary glimpse of his panic-stricken face just before the great mass of rock caught him and pinned him beneath the waters.

    Simultaneously with the terrific splash, a fearful, hysterical shriek rang out from the balcony high above our heads; and I knew that old Mrs. Stamm had witnessed the tragedy.

    We all sat in stunned silence for several seconds. Then I was conscious of Leland's soft voice.

    "A merciful death," he commented.

    Vance took a long, deep inhalation on his cigarette.

    "Merciful—and just," he said.

    The two men at the windlass had entered the water and were wading rapidly toward the place where Stamm had been buried; but it was only too obvious that their efforts would be futile. The great mass of rock had caught Stamm squarely, and there could be no hope of rescue.

    The first sudden shock of the catastrophe past, we rose to our feet, almost with one accord. It was then that the hall door opened and Doctor Holliday, pale and upset, lumbered out on the terrace.

    "Oh, there you are, Mr. Leland." He hesitated, as if he did not know exactly how to proceed. Then he blurted out:

    "Mrs. Stamm's dead. Sudden shock—she saw it happen. You had better break the news to her daughter."