Chet glanced all around to see if the way was clear, and had just raised his hand in signal to mount, when not only the buffaloes, but the horses, evinced sudden excitement. The whole herd stopped feeding, and the horses threw up their heads and snorted. “That old fool, Poke!” Dig muttered. “What does he want to make that noise for?” A long grey body shot from the thicket and crossed the plain directly ahead of the buffalo herd. It was running like the wind; indeed, it looked to be little more than a streak as it skimmed the sod. Neither boy had ever seen a running wolf before; but they did not need to be told what this was. With terror at his tail Mr. Wolf will match anything on four legs in speed. And something had certainly frightened this grey rascal. He had doubtless been lurking in the thicket, watching the buffalo calves and licking his chops at the sight. Something had started him for the distant Canadian border, and it looked as though he would get there presently. The wolf ran almost against the noses of the herd. The buffaloes huddled for a moment, the big bull snorting and bellowing. Then, as one creature, they wheeled in the track of the wolf, and set off at a lumbering canter that took them across the plain at surprising speed. “By the last hoptoad that was chased out of Ireland!” exclaimed Dig, in disgust. “Did you ever see such luck?” He ran to scramble on to Poke’s back; but Chet commanded him not to follow the herd at once. “No use adding to their fright. They may only run a few miles if they are not molested,” said Chet. “And not a shot after all that trouble!” Chet was staring at the thicket rather than after the stampeded buffaloes. “What under the sun could have started that wolf like that?” he muttered. “Come!” cried Dig excitedly from the saddle, “you’re not going to let ’em get entirely away from us, are you, Chet?” “I don’t believe we can get near them again today, Dig.” “Why not?” “After being scared like that they will be more watchful. And it’s two o’clock now.” “I don’t care. Why, Chet, those are real buffaloes!” “What’s the matter?” laughed his chum. “Did you think they were imitations at first?” “Whew!” blew Dig. “I certainly believed they were an hallucination. I didn’t believe there were such creatures. At least, not along this trail. “But now I’ve seen ’em—and been almost near enough to ’em for a shot—I tell you right now, Chet Havens, my blood is up! Let’s go after those buffaloes!” “Even if they lead us to the Arctic Circle?” laughed Chet. “Well, we have our camp equipment with us. Why not camp for the night where we happen to be? We can get back to the Grub Stake trail tomorrow.” “And poor little Stone Fence?” suggested Chet slyly. “Shucks! Maybe I’ll lasso one of those buffalo calves,” said Dig, grinning. “It would sell for more in town.”