"It wasn't what I'd figured on when I first walked in, but I had to make some excuse," he said. "Just now I'd very much like to know how far it went with him." He paused and looked thoughtful. "I guess it wasn't a very long way. The image is ahead of us by a dollar." Frank laughed. "You had some reason for going for that walk?" "Oh, yes," replied Harry. "I wanted to make sure of things, and the ground was soft. There were some footprints in it--going from the shack--and they'd been made quite lately by a white man's boot. John sticks to his slipper things in a general way. Anyhow, it was the man we saw who left those tracks." "How do you know that?" "There were a lot of others about, but they'd been made earlier. The water had got into them, but there was very little in those I was interested in." Frank was conscious that this was a point which would probably have escaped his notice, but he had not lived in the bush and learned to use his eyes. "It's very curious how the fellow got out of the shack without our seeing him," he said. "It looks curious until you begin to think. Now, though I tried to keep my eye on it all the while, the trees kept getting between me and the shack as we made for it, and what I couldn't see you couldn't see either. You were close behind me, which, in one way, was where we were wrong. If we had crept in well apart, the same tree wouldn't have bothered both of us, though if we'd done that it would have doubled the chances of our being seen." "A tree isn't such a very big thing," Frank objected. "No," said Harry. "The point is that it will shut an object a good deal bigger than itself out of your sight." He stopped a moment and pointed toward a neighboring cedar. "We'll say that one's three feet in diameter, but, as you're standing, it will shut off a good deal more than a track three feet wide through the bush. You want to run a line from your eye to both edges of the trunk and then carry them out behind it. The farther you run them, the farther they get apart, and as you can't see round a corner, everything in the wedge they enclose is shut out from view. Got that into you? It will come in useful when you're trailing a deer." It was quite clear to Frank now that it had been explained, but his companion went on. "Well," he added, "it wouldn't have taken that fellow more than a few seconds to slip out of the shack and in behind it. Then if he kept it between him and us he'd be hidden until he reached the bush." "Yes," said Frank. "It must mean that he saw us, and didn't want us to see him." "You're getting quite smart," said Harry with a grin. "I don't know if you noticed it, but you trod on a rotten branch that smashed. He didn't want us to know him again, but I'd pick that fellow anywhere by his back and walk. Now why was he so anxious that we shouldn't see him talking to the Chinaman?"