There was nothing for his two friends to do but to follow. They walked in silence, in single file, picking their way among the rocks. For a quarter of an hour or more they kept going, until finally they came to the ridge of hills, finding them enormous rocks, several hundred feet high, strewn closely together. "The valley must be right beyond," said the Doctor. "Come on." The spaces between these huge rocks were, some of them, fifty feet or more in width. Inside the hills the travelers found the ground even rougher than before, and it was nearly half an hour before they emerged on the other side. Instead of the shallow valley they expected to find, they came upon a precipice--a sheer drop into a tremendous canon, half as wide possibly as it was deep. They could see down to its bottom from where they stood--the same rocky, barren waste as that through which they had been traveling. Across the canon, on the farther side, lay another line of hills. "It's the scratch all right," said the Very Young Man, as they stopped near the brink of the precipice, "but, holy smoke! Isn't it big?" "That's two thousand feet down there," said the Big Business Man, stepping cautiously nearer to the edge. "Rogers didn't say it was so deep." "That's because we've been so much longer getting here," explained the Doctor. "How are we going to get down?" asked the Very Young Man as he stood beside the Big Business Man within a few feet of the brink. "It's getting deeper every minute, don't forget that." The Big Business Man knelt down and carefully approached to the very edge of the precipice. Then, as he looked over, he got upon his feet with a laugh of relief. "Come here," he said. They joined him at the edge and, looking over, could see that the jagged roughness of the wall made the descent, though difficult, not exceptionally hazardous. Below them, not more than twenty feet, a wide ledge jutted out, and beyond that they could see other similar ledges and crevices that would afford a foothold. "We can get down that," said the Very Young Man. "There's an easy place," and he pointed farther along the brink, to where a break in the edge seemed to offer a means of descent to the ledge just below. "It's going to be a mighty long climb down," said the Big Business Man. "Especially as we're getting smaller all the time. I wonder," he added thoughtfully, "how would it be if we made ourselves larger before we started. We could get big enough, you know, so that it would only be a few hundred feet down there. Then, after we got down, we could get small again." "That's a thought," said the Very Young Man. The Doctor sat down somewhat wearily, and again took the papers from his belt. "The idea is a good one," he said. "But there's one thing you overlook. The larger we get, the smoother the wall is going to be. Look, can't you see it changing every moment?"