Setting a prairie fire, when the person who did it could not but know it would eat its way toward a bunch of cattle, was a crime not far from horse stealing, than which there is no blacker offense in the West, where a man's life depends on his horse. And the person who was riding thus desperately away must have known, or at least feared, that quick vengeance would be dealt out to him. "Th' skunk!" muttered Pete, as he and the others swept on. "Th' mean, onery skunk!" Up came the sun from below the horizon, shining red in the smoke-filled air--red and dim, like some great balloon. The morning was hot with the heat of the fire, and it would soon be warmer and more depressing from the heat of the sun's rays. "It's a good thing dad has his cattle where there's some water for them," said Dave. "Yes," agreed Pete. "There isn't much, but it's better than being over at the other place, where Molick and his crowd can cut us off altogether." "If worst comes to worst, and he's built up that dam again," said the engineer, "we'll go and tear it down once more." "That's what we will," Pete said. "I'm not going to lose the cattle for want of some water, when we saved 'em from the fire." Dave was about to make a remark, when he gave a cry of surprise instead. "What's up?" asked Pete. "Look! If that isn't Len Molick I'll eat my rope!" cried the young cowpuncher. "Len Molick started that fire!" "It's him all right," agreed Pete, after an instant's glance. The figure racing on ahead so desperately had turned for a moment in the saddle, and this turning gave a view of his face. Dave had seen it was his enemy--the enemy who had taunted him with his lack of knowledge concerning his birth and parentage. "And we've caught him with the goods," remarked Pete, indulging in the slang which meant so much. "He'll go to jail for this." "If we catch him," suggested Mr. Bellmore. "Oh, we'll get him," declared Pete. "Come on here you cayuse you!" he called merrily to his mount. But alas for Pete's hopes. Whether the extra burst of speed was more than his horse could respond to, or whether in the excess of his zeal Pete forgot his usual caution probably would never be known. But the fact of the matter was that his horse Stepped into the burrow of a prairie dog, and, a moment later, the foreman went flying over the head of his steed, landing on the soft grass some distance away. Dave and Mr. Bellmore pulled up at once, but they had hardly done so before Pete leaped to his feet. "Ride on I Ride on!" he yelled. "Don't mind me. Get that skunk!" "But you may be hurt!" Dave called. "Hurt? No, not a bit! I'm all right!" "What about the horse?" asked the engineer. The animal had picked himself up, and walked with a limp toward his master, for Pete had trained him well.