The buccaneer's eyes stared wildly down into the great cenote, or water-tank, whose vast proportions were hidden in the gloom. He could see nothing; but his imagination supplied the vacancy, and pictured before him the head and shoulders of his treacherous follower as he swam along the sides of the great gulf, striving to find a place to climb up; and this he did, for the hoarse panting and the cries ceased, and from the dripping and splashing it was evident that he had found some inequality in the wall, by means of which he climbed, with the water streaming from him. The task was laborious, but he drew himself up and up, climbing slowly, and then he suddenly ceased, uttered a terrible cry, and once more there was a splash, the lapping and whispering of the water, and silence. He was at the surface again, swimming hard in the darkness and striving once more to reach the place where he had climbed; but in the darkness he swam in quite a different direction, and his hoarse panting rose again, quick and agitated now, the strokes were taken more rapidly, and like a rat drowning in a tub of water, the miserable wretch toiled on, swimming more and more rapidly and clutching at the wall. Once an inequality gave him a few moments' rest, and he clung desperately, uttering the most harrowing cries, but only to fall back with a heavy splash. Then he was up once more fighting for life, and the vast tank echoed with his gurgling appeals for help. Again they were silenced, and the water whispered and lapped and echoed. There was a splash, a hoarse gurgle, a beating of the water as a dog beats it before it sinks. Again silence and the whispering and lapping against the sides more faint; then a gurgling sound, the water beat once or twice, a fainter echo or two, and then what sounded like a sigh of relief, and a silence that was indeed the silence of death. Suddenly the silence in that darkness was broken, for a hoarse voice said-- "Climb up!" "Climb!" exclaimed Humphrey, who seemed to have recovered his voice, while his frozen energies appeared to expand. "Yes. Climb. I can hold you thus, but no more. Try and obtain a foothold." Humphrey obeyed as one obeys who feels a stronger will acting upon him. "Can you keep my hands fast?" he said. "They are numbed." "Yes. You shall not slip now. Climb!" Humphrey obeyed, and placed his feet upon a projection; but it gave way, and a great stone forced from the wall by his weight fell down with a splash which roused the echoes once more. Humphrey felt half-paralysed again; but the voice above was once more raised. "Now," it said, "there must be foothold in that spot where the stone fell. Try."