The boys’ faces were flushed with excitement as the return ride was begun. Eagerly they discussed between themselves the probabilities of recovering Jack, while the captain rode with bowed head as if buried in thought. The mystery of Jack’s fate worried him deeply, and he was beginning to think that there were more complications to it than he had at first imagined. It was an hour after that the search party set forth. They carried blankets, emergency kits, food, firearms and hatchets. Also each had a stout rawhide lariat, each “rope” being about forty feet in length. Thus equipped they started out on what was to prove a most eventful journey, and one in which they were destined to encounter more surprises than they dreamed. By sunset the first day of their search they found themselves in a wild canyon through which the river flowed swiftly. Camp was made at a spot near which a clear spring of water gushed from a wall of the place. It was slightly alkaline, but they did not mind that, as it was preferable even as it was to the muddy, discolored waters of the Rio Grande. The ponies were picketed, a fire was lighted, supper cooked and things put in order for the night. It was not a cheerful party that gathered about the camp fire. All of them were pretty well exhausted and disheartened by their absolute failure to find any trace of Jack. Captain Atkinson alone would not admit discouragement. He did all he could to keep up the flagging spirits of the two lads, and after supper had been despatched he inquired if they would care to hear some of his experiences on the Border. “Gladly,” declared Ralph, relieved to hear something that might, for a time at least, take his mind off the possible predicament of his chum. Captain Atkinson paused to cram his old black pipe with strong tobacco, light it with a glowing coal, and then plunged into his story. As he talked the murmuring voice of the river and the sighing of the night wind in the scanty trees of the canyon formed a fitting accompaniment to his narrative. “Some years ago,” he began, “I was foreman of a small ranch in the neighborhood of Las Animos, in the eastern part of the state. It was at a time when cattle and horse thieves, ‘rustlers’ as we call them, had been particularly active. Hardly a rancher in the vicinity but had suffered from their depredations, and feeling ran pretty high against them, I can tell you. “Well, our ranch, which was known as the Flying U, had managed somehow to escape unscathed, although all round us the rustlers had been operating boldly and openly. Their method was to raid a ranch, drive the cattle or horses across the Border and then sell them to Mexican dealers, who drove them to the coast and there disposed of them as best they could. Many were shipped to European ports, so I heard.