He hesitated no longer. With a shudder he put his hand into the dead man's pocket, and drew forth the silver key. It was the work of a moment to light the little hand-lamp, and pass forward into the library. Then he went down on his knees to look for the marks he had made on the carpet which were to point out to him the exact position of the secret door. Having found them, together with an almost invisible scratch which he had made on a particular part of the polished panelling of the bookcase, he was guided at once to the spring by which the secret door was acted upon, and in another moment the narrow stone staircase opened darkly at his feet. Down the stairs he went without pause or hesitation, carrying the lighted lamp in one hand and the pass-key in the other. The door at the bottom of the staircase opened without difficulty, and he found himself in the low vaulted chamber at the further end of which was the door that opened into the rock. The second door was passed as readily as the first, and before him appeared the narrow passage that led to the cavern. To-night the cold moist atmosphere of the place struck upon him with a chill that made him shudder. He had trodden that passage but once before, and then it was in company with the man who now lay cold and dead in the room above. He gave a backward glance over his shoulder half expecting to see the shade of Platzoff following silently in his footsteps. But there was nothing save his own distorted shadow dogging him like some monster at once ugly and grotesque. With a sneer at his own timidity he entered the passage in the rock. In three minutes more the great prize would be his.
Slowly and cautiously he threaded the tortuous pathway that led to the heart of the hill. He reached the end of it in safety, and the cavern loomed dim and vast before him. He paused for a moment, and held the lamp high above his head. There, fixed in the middle of the sandy floor he could just make out the vague outlines of the Indian idol. The great gem that flashed in its forehead caught a ray from the feeble lamp held by Ducie, and flung it back intensified a thousandfold. Dude saw the flash; and his breath came thick and fast.
He advanced one step--a second. Then, before he knew what had happened, he found himself stretched on the floor of the cave and in utter darkness. He had stumbled over some inequality in the floor, and had dropped his lamp in falling. Bruised and bleeding, and with a curse on his lips, he rose to his feet.
The predicament in which he now found himself was anything but a pleasant one. That he could find the idol even in the dark, and make himself master of the Diamond, he did not doubt. But the question was, whether if he wandered so far away from the narrow passage by which access was had to the cavern, he could find it again, and so get back to the library before the clock struck twelve. If that could be done all might yet be well. If it could not be done--but he would not stop to argue the point. He would make a bold dash for the Diamond. He would risk everything in one final throw, and trust that the good fortune which had so far befriended his enterprise would not desert him in this great crisis of his fate.
A few seconds sufficed for him to weave these thoughts in his brain, and almost before he had decided on what he would do he was advancing deeper into the cavern; advancing slowly, step by step, with outstretched arms, in the direction of the idol. By the light of his lamp he had noted its position, and now that he was in the dark he went to it nearly in a straight line. Suddenly it seemed as though the idol had risen noiselessly from the ground. The palm of his left hand smote its flat cold forehead. He lost not an instant in feeling for the Diamond. The moment his fingers touched it he thrilled from head to foot.
The Diamond was held in its place in the forehead of the idol by a small gold clasp which worked in the hollow of the skull. It occupied Ducie some three or four minutes, first to find the clasp, and afterwards to unfasten it. At length he succeeded in opening it, and the Diamond dropped into his palm. His own at last!
With a great sigh of relief and thankfulness he drew back his arm, and having first kissed the gem, he put it carefully away into a safe pocket, and then turned to retrace his steps. Taking the nose of the idol as his starting-point, he calculated that a straight line from it to the wall of the cavern would not land him very wide of the entrance. But the difficulty was to keep a straight line in the dark, and the darkness of the cavern was something that might almost be felt. But there was no time for hesitation. If midnight had not struck already it must be close on the point of doing so. The delay of a single minute might be the cause of his discovery either by Cleon or Jasmin. What the result would be in such a case he did not pause to ask himself. Instead, he set himself with his back to the face of the idol and stepped out slow and steady for the side of the cave.
He had got about half way across the intervening space when a sound fell on his ear that brought him on the instant to a dead stand. It was the noise made by some one descending the stone stairs that led into the vaulted room. All had been discovered, then! The death of Platzoff, the secret door standing wide open, and his, Ducie's, disappearance. The intruder must be either Cleon or Jasmin. Was either of them aware of the existence of the Diamond, and that it had been hidden in the cave? If not, then his presence there could be easily excused on the score of simple curiosity to see so strange a place. If they knew of the existence of the Diamond, they would suspect at once that he had taken it, and would doubtless try to dispossess him of it by force. Well: they should not take it from him without taking his life also: on that point he was fully determined. Presently a thin ray of light which cut the darkness like a sword, shone through the narrow entrance to the cave. It broadened and brightened quickly. As it drew nearer, Captain Ducie advanced to meet it. His face was pale, but very set and determined. His eyes shone from under his heavy brows with a light that boded no good to the intruder whoever he might be. He was not left long in doubt. Another half-minute brought into view the gaunt figure of Cleon, newly-risen from his sick bed. With haggard face and bloodshot eyes, and with a snarl of the lips that showed his long narrow teeth, the mulatto advanced slowly and warily. In one hand he carried a lamp, held high above his head; in the other a gleaming dagger. Ducie advanced towards him haughtily, with folded arms. As Cleon emerged from the into the cave his eyes fell on the captain's tall figure. He smiled a ghastly smile, and slowly nodded his head twice.
"Thief and villain! I have found you at last," he said. "Your heart's blood shall dye the floor of this cave."
He set down his lamp on a projection of the rock, and deliberately turned back the cuffs of his coat. Captain Ducie said never a word in reply, but kept his eyes fixed unswervingly on Cleon, as he would have done on a tiger or other beast of prey. He was without a defensive weapon of any kind, and was obliged to trust to the quickness of his eye and the strength of his muscles for safety in the coming attack.