He drove the horse on without mercy, forcing it at a swift pace over the rough country, trying all the time to pick ground that would leave a poor trail. As they thus rode on they heard the wild war whoops that announced either their discovery, or that the Indians had encountered the young chief, Lightfoot, and learned from him what had occurred. “Now, we must ride--ride!” said Clayton, and he bent forward in the saddle, lashing the horse on, and using the spurs mercilessly. Again the wild yells of the Blackfeet broke forth. “They may be yelling for some other reason,” she said, trying to encourage her lover. “Yes; they may have sighted Cody and Pawnee Bill,” he assented. “There’s no telling; but they’ve struck something, some trail or some enemy, and, like a pack of hounds when the game is scented, they can’t help yelping.” The path grew rougher, if that can be called a path which was more than half the time but a broken game trail, that played out and began again in the most eccentric manner. They had gained a high shoulder of the hills, and below them lay open country, that stretched on into illimitable distances, where there was much coarse grass. “There is one way of defeating those scoundrels--of keeping them from seeing our trail,” said Clayton, at last; “and that is to burn it.” “Burn it?” “Yes; ride down into that, and fire the grass, and then make our flight behind the fire and the smoke.” “And have the fire overtake us and burn us to death! But try it; I’d rather be burned to death than to fall into the hands of those awful and merciless Blackfeet.” He guided the horse down the slope and on toward the grassy levels that lay beyond. Ten minutes later he was well out in the grass. Here he stooped from the saddle, pulled a handful of dry grass, to which he applied a lighted match, and then threw it down. While he did this the horse stood panting, sweat dripping from it. Young Clayton had seen that he must do something desperate, if he escaped the Blackfeet; and this was the thing he was now to try. The burning grass communicated fire to that surrounding the horse. Clayton sent the animal on, and with a few leaps it left the conflagration behind it. The remarkable manner in which the fire spread through the dry grass was worthy of comment. It flamed up with a roar. Seeming to create a wind from the rising currents of heated air, the fire began to run before the breeze, leaping along in an amazing way. It spread round from the spot where it had been started, burning backward toward the hills and outward in the direction taken by the horse. “Now, for a race!” thought Clayton, struck by a sudden fear, as he saw how fast the fire was spreading. “Maybe that will be worse to get away from than the Blackfeet; and if anything should happen to the horse we’ll have to run for our lives!” He voiced none of this to the girl.