Hour after hour, in the heat of the day or the cool of the evening, the giant Mexican strode on by the side of the two horsemen, sometimes trotting like a dog, more often walking with a shambling, wide-reaching step, tireless as any wild animal. His feet, seamed and parched into the semblance rather of horn than of flesh and bone, were quite bare, though now it was a time of year when the nights at least were very cool and when freezing weather might come at any time. He was clad lightly as ever, in torn cotton garb, and carried no bedding save a narrow strip of native woollen fabric, woven of undyed wool and so loose of texture that one might thrust a finger through at any point of its scant extent. He bore no weapon save the huge knife swinging at his belt. Fastened to the same girdle was a hide bag or pouch, half full of parched corn, rudely pounded. Expressionless, mute, untiring, the colossal figure strode along, like some primordial creature in whom a human soul had not yet found home. Yet, with an intelligence and confidence which was more than human, he ran without hesitation the trail of the unshod horse across this wide, hard plain, where even the eye of the cowboy could rarely discern it. Now and then the print of the hoof might show in the soft earth of some prairie-dog burrow; then perhaps for an hour Juan would walk on, his eye fixed apparently upon some far-off point of the horizon as upon the ground, until finally they would note the same hoof-print again and know again that the instinct of the wild guide had not failed. The Mexican was running the back trail of the horse of Cal Greathouse, the missing ranchman, and it was very early seen that the horse had not returned over the route taken by Greathouse when he started out. He had gone along the valley of the Smoky River, whereas the course of the loose animal had been along the chord of a wide arc made by the valley of that stream, a course much shorter and easier to traverse, as it evaded a part of that rough country known as the breaks of the Smoky, a series of gullies and "draws" running from the table-land down to the deep little river bed. All along the stream, at ragged intervals, grew scattered clumps of cottonwoods and other trees, so that at a long distance the winding course of the little river could be traced with ease. The afternoon of the first day brought the travellers well within, view of this timber line, but the rough country along the stream was not yet reached when they were forced to quit the trail and make their rough bivouac for the night.