While this conversation was going on, Charley had slipped away from the little circle unnoticed, and stepped softly out into the darkness. He had not gone far before he was halted by an abrupt challenge and a leveled rifle. "It's the boss," he said, in answer to the challenge. "Where's Gomez?" "Gomez is on the other side of the camp," answered the sentinel in Spanish. "Each of us make a half circle of camp, meet, and turn back again. No one can go or come unnoticed." "_Esto bueno. Bueno nosche, hombre._" (It is good. Good night, man.) "_Bueno nosche, señor_," replied the Spaniard politely, and Charley strolled back to the fire, satisfied that the night guards were doing their duty. "Jim," he said, to the teamster, "I want to use one of the mules to-morrow. You've got enough wood hauled to last a couple of days. You can keep right on chopping while I'm gone. Take Juan out with you. He is to be your regular helper. Now, which mule had I better take?" "Going to ride?" inquired the teamster. "Yes." "Waal," he said thoughtfully, "Violet will throw you the furthest, but Pansy might kick you while you're down." "I'll take Violet," decided the lad, with a grin. "I object to being kicked when I'm down." "I'm going to take a ride ahead to-morrow," he told his chum, when the rest had retired. "I am in hopes that I may hit on some clew to this mystery. At any rate I will look over the route we have to take, and see what we have got to encounter. I ought to have done that before we bought Murphy out. Well, here goes for bed. I am going to get an early start in the morning." His intentions were sincere, but he slept so soundly that he did not awaken until the general call for breakfast. While he was eating Chris put up a lunch for him, and, when he was through, Jim, the teamster, accompanied him out to the corral. "I'll put the bridle on Violet for you," he offered. "She sorter objects to strangers fooling around her mouth." "All right," Charley agreed, but it was with some little secret dismay that he viewed the towering, powerful mule, as Jim bridled it, and, throwing a sack over its back, led it out of the corral. It was too late to back out without chaffing, for the whole camp had paused on its way to work, to watch the proceedings. "Lead it out on the grade and give me a hand up," he ordered, and Jim meekly obeyed. Charley placed his foot in the teamster's hand and swung himself lightly astride of the mule, while the teamster jumped hurriedly back. "Get up," Charley said, as he gathered up the reins. Down went the mule's head, and up and down went its hind part, in a series of jolting, jarring bucks. "Give it the whip," howled Walter in delight. But Charley was too busy to heed advice. He grasped desperately at the mule's mane to save himself, but it was too short for a hand-hold, and over the mule's head he went, to land ten feet away in the soft sand with a thud that made his teeth ache.