She was certain at last he was murdered in the cave, and that now, with the passageway finally known, the fiends, whose passion was taking human life, had come to complete their tale of butchery and plunder. Why else should they once more visit the hill at such an hour of the morning? They had barely waited for the dawn to make certain of their work! She saw them coming furtively up the trail, aware, she was sure, that by means of the hidden gallery their movements might be seen. She had held a wasting firebrand in her tense little fist for the past two hours. And now--if only Sidney had told her what to do in such an extremity as this! If only it might be her duty to fire the cannon! It seemed as if she must obey the impulse--and perhaps save both of their lives! The Dyaks were almost at the bridge. They must soon come fairly in range of the gun! After that--it would be too late! Below, in the cavern, during this time, Grenville was haunted with doubts. He had waited in hopes other Dyaks would come, and not a sound had rewarded his straining senses. He began to fear he had waited too long--that the creatures whose shadows had crept within had searched all the place and departed. Yet he knew that they could not have passed him and left him unaware. The light was now all in his favor, and steadily increasing. With a sudden determination to take what toll the Fates had offered, he groped his way back to his brands of fire, and then to the ends of his fuse. Elaine, with her heart all but bursting, with excitement for which she had no vent, saw the head-hunters pause on the slender bridge before they crept upward as before. Her weight was leaned against the door till it moved a little from its bearings. She was sure it had made some far-reaching sound that the Dyaks could not fail to hear. They had paused again--and again moved up the trail--and found her helpless. The cord on her arm!--if Sidney would only pull the cord---- The sharp little tug that suddenly came now startled a cry from her lips. Instantly thrusting away the door and bounding from the narrow ledge to the upper level of the terrace, she ran towards the fuse with her cone of fire, just as Grenville, down in the gallery of rock, came madly plunging upward. He had lighted the fuse, and was groping towards the top, a fear that he might be buried pursuing at his heels. He stumbled across the heavy load of treasure, left in its basket by the wall. As one in an earthquake or fire clutches up something to save it, instinctively, so he laid hold of this useless dross and tugged it hotly up the passage. He reached the upper angle thus before he realized the folly of his action. He was certain then, as he dropped the load, that something had happened to his mines. Before this time---- With the thought half finished in his swiftly-working brain came the thud and shock of his explosion--a tangible movement in the bulk of rock--and then the cataclysm.