In vain Jack protested he knew nothing about the horse's escape. Lem's temper was bad from the effects of his drinking bout, and as ill-luck would have it, the boy was the victim of it. 'Look here, kid,' he said sternly, 'it was your business to see to them creatures when we were gone away, an' I guess you'll skip out an' find that there Nigger as quick as you can. Not a step on with us do you go, till he's brought back again!' [Illustration: '"YOU'D BETTER NOT COME BACK WITHOUT THE HORSE."'] 'I've looked all round the camp this mornin',' said Jack dolefully, 'but I haven't seen no tracks of him. Would you let me get on Yankee Boy an' ride over to that clump of trees over there?' 'No! I guess you can walk that far,' returned Lem, 'an' I reckon you'd better not come back again without the horse. I mayhap would like to ride Yankee Boy mysel' an' have a look round.' Poor Jack! He looked wistfully at the recumbent figure of Jeff, who was still in a deep slumber, and then, seeing there was no help for it, bravely put the best face he could on the matter, and set forth. He carried a long leather rope to catch the horse with, and walked towards the trees, which were about a couple of miles from the camp. As he approached them, he noticed they were growing at the entrance of a deep ravine that ran back towards the mountains, with a creek running through it. It was a very rough place; boulders lay strewed about, but here and there were patches of grass which looked so much fresher and greener than that which grew on the prairie, that Jack noticed the difference. It also struck him that the grass looked as if it had been freshly trampled, and in a moment the idea flashed into his mind that Nigger had, without doubt, wandered up the ravine. Jack never hesitated a moment, but started to follow up the tracks he saw so plainly. It was a pleasant change from the hot prairie, as the trees shaded him from the sun, and he climbed steadily on over the stony path, hoping every minute to come on the truant. The ravine ran between towering walls of rock, covered with piñon and oak-scrub, and completely hid all the adjoining prairie from view.