This was strange and excited his curiosity. The other's figure would probably be invisible against the rock, but he must have moved rapidly to get in front of it. Then Thirlwell saw that where he stood the bush was no longer behind him. He had the inshore eddies for a background and the water reflected a faint light. There was no obvious reason why the other should be alarmed and try to steal away, but it looked as if he had done so. Thirlwell sat down among the driftwood and waited, but saw no more of the man; and then going back quietly, turned into a trail that led to the mine. The trail was rough and narrow; in places, short brush had sprung up, and there were patches of outcropping rock. It would be difficult for anybody to follow it without making some noise, but although he stopped and listened no sound came out of the gloom. He went on, pondering the matter with some curiosity. Since the miners were in camp, he imagined the man he had seen was Driscoll, who lived alone in a log shack near the bank. But, if this were so, what was Driscoll's object for wading among the reefs, and why had he stolen away when he thought he was watched? Thirlwell could not solve the puzzle, but he could find out if the fellow were Driscoll or not, because the trail passed his shack. He walked faster, making as little noise as possible, and by and by reached a belt of thinner forest. He passed a fallen pine, from which he knew the shack was visible in daylight, and resolved to see if Driscoll was at home. If not, Thirlwell thought it would be safe to conclude that he had seen him among the reefs. A few moments later a light flashed among the trees, flickered once or twice, and then burned steadily. Thirlwell knew it came from the window of the shack, but it was curious that Driscoll had lighted his lamp. In summer, miners and prospectors went to bed at sunset, and Driscoll read no books or newspapers. Besides, if he wanted a light, why had he not got it before? It, however, looked as if the man had not been at the rapid and when Thirlwell passed the shack he saw his dark figure at the door. "Who's that?" he asked, and when Thirlwell answered, added: "Watch out as you go down the gulch. There's a rampike across the trail." When Thirlwell came to the burned pine he stopped abruptly as a thought struck him. Driscoll's voice had sounded breathless; perhaps the fellow had overdone his part. It might have been wiser for him to be silent. Driscoll often went fishing and knew the river well; now the water was low he could have saved some distance by crossing the uncovered reefs instead of scrambling along the curved bank. Besides, he had had a few minutes' start. After all, he might have been at the rapid and have hurried back in order to deceive the man who had disturbed him. Moreover, he had learned who the man was.