As straight as a bee-line Wildfire had left a trail down into the floor of the valley. He had not stopped to graze, and he had not looked for water. Slone had hoped to find a water-hole in one of the deep washes in the red earth, but if there had been any water there Wildfire would have scented it. He had not had a drink for three days that Slone knew of. And Nagger had not drunk for forty hours. Slone had a canvas water-bag hanging over the pommel, but it was a habit of his to deny himself, as far as possible, till his horse could drink also. Like an Indian, Slone ate and drank but little. It took four hours of steady trotting to reach the middle and bottom of that wide, flat valley. A network of washes cut up the whole center of it, and they were all as dry as bleached bone. To cross these Slone had only to keep Wildfire's trail. And it was proof of Nagger's quality that he did not have to veer from the stallion's course. It was hot down in the lowland. The heat struck up, reflected from the sand. But it was a March sun, and no more than pleasant to Slone. The wind rose, however, and blew dust and sand in the faces of horse and rider. Except lizards, Slone did not see any living things. Miles of low greasewood and sparse yellow sage led to the first almost imperceptible rise of the valley floor on that side. The distant cedars beckoned to Slone. He was not patient, because he was on the trail of Wildfire; but, nevertheless, the hours seemed short. Slone had no past to think about, and the future held nothing except a horse, and so his thoughts revolved the possibilities connected with this chase of Wildfire. The chase was hopeless in such country as he was traversing, and if Wildfire chose to roam around valleys like this one Slone would fail utterly. But the stallion had long ago left his band of horses, and then, one by one his favorite consorts, and now he was alone, headed with unerring instinct for wild, untrammeled ranges. He had been used to the pure, cold water and the succulent grass of the cold desert uplands. Assuredly he would not tarry in such barren lands as these. For Slone an ever-present and growing fascination lay in Wildfire's clear, sharply defined tracks. It was as if every hoof-mark told him something. Once, far up the interminable ascent, he found on a ridge-top tracks showing where Wildfire had halted and turned. "Ha, Nagger!" cried Slone, exultingly. "Look there! He's begun facin' about. He's wonderin' if we're still after him. He's worried.... But we'll keep out of sight--a day behind." When Slone reached the cedars the sun was low down in the west. He looked back across the fifty miles of valley to the colored cliffs and walls. He seemed to be above them now, and the cool air, with tang of cedar and juniper, strengthened the impression that he had climbed high.