By and by he climbed and passed out of the zone of brush. He was on the open gravel ridges, like the ridges of a washboard, up and down, and just as bare. Yet, as a whole, there was a distinct slope upward. He could not see the level of the desert, but the lone mountain peak, close at hand now, red and black and shining, towered bleakly over him. Adam derived satisfaction from the fact that the hard gravel ridges did not take imprint of his boots. Assured now that escape was in his grasp, he began to put his mind upon other considerations of his flight. He was not such a fool as to underrate the danger of his venturing out upon the desert without food, and especially without water. Already he was thirsty. These thoughts, and counter ones, pressed hard upon him until he surmounted the long slope to the top of the desert mesa. Here he looked back. First he saw clouds of dust puffing up from the brush-covered lowlands, and then, in an open space where the road crossed, he espied horsemen coming at a gallop. Again, and just as fiercely, did his veins seem to freeze, his blood to halt, and then to burst into flame. “Collishaw--and his men!” gasped Adam, his jaw dropping. “They’ve trailed me!... They’re after me--on horses!” The apparent fact was terrific in its stunning force. Adam reeled; his sight blurred. It was a full moment before he could rally his forces. Then, gazing keenly, he saw that his pursuers were still miles away. At first he ran fleetly, with endurance apparently unimpaired, but he meant to slow down and husband his strength as soon as he dared. Before him stretched a desert floor of fine, shining gravel, like marbles, absolutely bare of any vegetation for what seemed hundreds of yards; and then began to appear short bunches of low meager brush called greasewood, and here and there isolated patches of _ocatilla_. These multiplied and enlarged in the distance until they looked as if they would afford cover enough to hide Adam from his pursuers. Hot, wet with sweat, strong, and panting, he ran another mile, to find the character of the desert changing. Reaching the zone of plant life, he soon placed a thin but effective barrier of greasewood and _ocatilla_ behind him. Then he slowed down to catch his breath. Before him extended a vast hazy expanse, growing darker with accumulated growths in the distance. To the right rose the chocolate mountain range, and it ran on to fade in the dim horizon. Behind him now stood the lone black peak, and to the left rose a low, faint wavering line of white, like billows of a sea. This puzzled him until at length he realized it was sand. Sand--and it, like the range, faded in the distant horizon.