"We have got to fight fire with fire," he explained to Walter, as he headed for the path the guards had trod down in the grass. "Just outside the path is the best place to start a back fire. The path will help to keep it from working back on the tents." The two lads tore up big bunches of dry grass, and, lighting them, ran along the half-circle path, scattering fire as they went. The Spaniards were quick to catch the idea, and, stationing themselves at regular intervals along the path, with their green spruce boughs they beat out the flames that leaped the little path and threatened the tents. The prairie grass was knee high, and as dry as tinder, and, although the wind was against it, the back fire ate its way steadily back toward the leaping flames. "We have done all we can," said Charley to his chum, as they stood watching anxiously the approach of the flames. "It's a toss-up whether we will win or not. If our camp goes, we are done for, that's all. We haven't got the money to refit again. My! that would be a wonderful sight to enjoy if our future wasn't hanging in the balance." It was, indeed, a wonderful sight. The fire, now scarcely a quarter of a mile away, was sweeping steadily down upon them, a solid wall of flame ten feet high licking up the dry grass with a roaring cackle like a mighty wind in a forest, while toward it the back fire was slowly but steadily eating its way. The space between the two fires was as bright as day, and in it the lads could see scores of animals, running bewildered here and there, trapped between the two lines of flames: deer, coons, wild-cats and foxes ran back and forth in frantic terror. Within twenty feet of where the boys stood a lithe form cleared the flames of the back fire in a mighty leap, and rushed by the tents, heedless of the presence of human beings in its mad flight for safety. "A panther," commented Charley briefly, as the terror-stricken animal rushed by.