For hours, so it seemed to him, he was swimming before his outstretched hand touched solid stone. Treading water, he reached upward, striving to discover how high this barrier was; but the top was beyond his reach. Sheer and solid the masonry rose, without crack or crevice by means of which one might climb. Somewhat disappointed, Seymour turned and swam slowly along the base of the wall. What this barrier meant he could not at first determine. The touch of it told him that it was no work of Nature. No natural wall had ever its smoothness and regularity. Yet for what purpose had it been built? Like a flash into his brain swept the answer. This was the ancient reservoir of the Ayutis, which fed the great tanks beneath the temple. The thought gave him hope, for, if his idea were correct, there must be some exit through which the water flowed into the conduits. Steadily he swam forward, feeling the wall as he went, till suddenly, thrusting out his hand, he felt nothing. The wall had ended! Eagerly he felt about him. Yes, there was no doubt about it, the masonry had ceased. Three cautious strokes, at right angles to his first course, and his feet touched the lowest of a flight of steps which here broke the regularity of the wall, running down some feet into the water. Thankfully he drew himself up, and sat a while to rest, ere ascending to the top of the flight. His position was a most unenviable one. Naked, wet, and shivering from his immersion, buried in some subterranean cavern far away from even the ghostly light of the underworld, and, above all, entirely defenceless, it was not remarkable that he felt somewhat depressed. But summoning all his courage he rose after a few moments and mounted the steps, moving carefully, lest he should lose his footing and fall backward into the water again. Twelve of the steps he counted, then found himself upon an apparently broad pavement, across which he crept, hands outstretched before him. The silence was intense. No sound but the gentle lapping of the water against the stonework came to his ears, and even this ceased as he increased his distance from the reservoir. Step by step he advanced, gaining courage with every yard, until, with a suddenness that sent his heart leaping into his mouth, a sound came out of the darkness ahead--_the snarling yelp of some animal!_ The baronet pulled up on the instant and stood listening. Again the yelp came to his ears, trembling away weirdly into the furthermost recesses of the vast cavern. What creature could it be that dwelt here in the darkness? he asked himself. Was it the wolf-man who had fallen with him into these depths? Even as his mind framed the question he knew that it was so. The savage had escaped from the reservoir, and was now prowling somewhere in the gloom ahead of him.