Boyd rode in front, Will was just behind, and then came the two heavily laden pack horses, following their masters with a faith that nothing could shake. The hunter seemed to have an instinct for choosing the right way, or else his eyes, like those of an owl, were able to pierce the dark. He avoided chasms and cliffs, chose the best places on the slopes, and wherever he wound he always led deeper and deeper into the vast maze of high mountains. Will looked back toward the plains, but he could see no trace of them now, and he did not believe that the Sioux, however skilled they might be, could follow their trail up the ridges in the dark. Meanwhile the stars came out, and a half moon rode in a medium sky. The boy's eyes, grown used to the night, were now able to see quite clearly, and he noticed that the region into which they were riding was steadily growing wilder. Now and then they passed so close to the edge of chasms that he shivered a little, as he looked down into the dark wells. Then they passed up ravines where the lofty cliffs, clothed in stunted pine and cedar, rose high above them, and far in the north he caught the occasional glimpses of white crests on which the snow lay deep. Boyd became quite cheerful, and, for a while, hummed a little air under his breath. When he ceased singing he said: "I don't know where we're going, Will, but I do know that we're going away from the Sioux. They'll try to trail us tomorrow when the light comes, and they may be able to do it, but we'll be moving on again, and, however patient trailers may be, a trail that lengthens forever will wear out the most patient trailer of them all." "Isn't that a creek down there?" asked Will, pointing to a silver flash in the dusk. "So it is, and while these mountain streams usually have rough beds, scattered with boulders, we'll ride up it as far as we can. It may be a great help in hiding our trail." They rode down the slope and urged the horses into the water, although the good beasts showed reluctance, fearful of the bowlders and the rough footing, but, when they were in, the two riders allowed them to pick the way, and thus they advanced slowly and with extreme caution a distance of five full miles. They heard a roaring and approached a fine fall of about thirty feet, over which the creek tumbled, sending up much white foam. "This watery road is now blocked, that's quite sure," said Boyd. "But we've been able to use it a much greater distance than I thought, and it may throw off the Sioux entirely."