Chunky uttered a yell as he found himself bumping against the sides of the cows and sought to turn his pony about. The startled steers nearest to him fought desperately to get away from the object that had so suddenly hurled itself against them. Instantly there was a mix-up, with bellowing, plunging steers all about him. "Help! Help!" shouted the boy. Now his pony was biting and kicking in an effort to free itself from the animals that were prodding it with horns and buffeting it from side to side. Only a moment or so of this was necessary to fill the cattle with blind, unreasoning fear. With one common impulse they lunged forward. Those ahead of them felt the impetus of the thrust just as do the cars of a freight train under the sudden jolt of a starting engine. "What's up?" roared the foreman. "They're off!" yelled a cowman. "Head them!" "Can't. They're started in the center of the herd." With heads down, the entire herd was now charging straight ahead. Big-foot Sanders and Tad Butler, nearly half a mile ahead, felt the impetus, too. "Keep your head, boy," warned the cowpuncher. "We are in for a run for our money, now." It came even as he spoke. With a bellow the cattle started forward at a lively gallop. "Whoa-oo-ope!" cried Big-foot, riding in front of the plunging leaders. He might as well have sought to stay the progress of the wind. The leaders swept man and boy aside and dashed on. "Better keep them straight and not try to stop them, hadn't we?" shouted Tad, with rare generalship. "That's the trick! Can you hold your side?" roared Big-foot in reply. "I'll try," answered the boy, riding so close to the leaders that they rubbed sides with his pony. The latter, understanding what was wanted of him, pushed sturdily on holding the cattle with his side, leaning toward them to give the effort the benefit of his entire weight. One end of Tad's neckerchief had come loose and was streaming straight out behind him, while the broad brim of his sombrero was tipped up by the rushing breeze. It was a wild and perilous ride. Yet the lad thought nothing of this. His whole thought was centered on the work in hand, that of keeping the cattle headed northward. Tad was unable to tell whether they were going in a straight line or not, but this time he had the big cowman to rely upon. "Give way a little!" warned Big-foot. "Right!" answered the lad, pulling his pony to one side, then straightening him again. "We'll hit the Injun Territory by daylight if we keep on at this gait! You all right?" "Yes. But I think the herd is spreading out behind me," answered Tad. "Never mind that. They'll likely follow the leaders."