“That’s my idea, too,” declared Walt stoutly. “Well, I admire the confidence you boys have in your leader,” declared Captain Atkinson warmly, “but just the same as soon as it’s daylight I mean to start a thorough investigation, and if harm has come to him it will go hard with those that caused it.” CHAPTER XII. A BAFFLING PURSUIT. But a close scrutiny of the river banks by daylight failed to reveal anything more definite than a maze of trampled footmarks and broken brush at the spot where Jack had encountered his combat with the three Mexican spies. Captain Atkinson, one of the most expert of men in the plainsman’s art of reading signs from seemingly insignificant features, confessed that he was baffled. “It is plain enough that Jack was involved in some sort of a fight,” he said, “but beyond that I cannot say. The most puzzling thing about his disappearance, in fact, lies in the absence of pony tracks. I can’t imagine how whoever it was attacked him reached this vicinity without being heard by the sentries east and west of the trail.” “Can it not be possible that in some manner he fell into the river and was swept away by the swift current?” inquired Ralph. The captain shook his head. “Of course, it is possible, but it hardly lies within the range of probabilities,” he declared. They were still discussing the extraordinary situation when Baldy uttered an exclamation. He had been examining the river bank and now he held up a bit of rope that he had discovered on the verge of the stream. “Look here, cap,” he cried, “I’m a long–horned maverick if this ain’t queer.” “A bit of rope, eh, Baldy?” rejoined the captain. “Well, that would seem to indicate that something had been tied there. Clearly it was not a horse or we should see the tracks. It must then have been————” “A boat!” burst in Walt, unable to control himself. “How could a boat ever get along in this shallow, swirling stream?” cried Ralph. “No; but some contrivance of logs that would float, such as a raft, might have navigated the river,” suggested Captain Atkinson, little guessing how close he was to the truth. The captain now had the rope in his hands and was examining the frayed end. “This rope has been recently severed,” he decided. “Cut?” questioned Ralph. “No, broken,” was the rejoinder. “Then ther kid must have gone down the river,” said Baldy. “Undoubtedly,” rejoined the captain. “In that case we must follow the stream in search of him,” cried Walt. “Yes. We will start as soon as possible, too. Baldy, see that everything is made ready for us at once.” “Ain’t I going along, cap?” pleaded Baldy. “No; I shall leave you in command of the camp till I return. In the meantime the boys and I will ride back with you to camp and prepare for our expedition.”