“The Blackfeet haven’t been sighted yet,” he said to her. “They’ll know, of course, or guess, that we’ve taken to the grass, and set it on fire; but after that black smoke gets to rolling and the fire to running good, it will be hard for them to tell where we have gone, and I defy them to follow our trail after the fire has burned the grass.” Before he had ridden a mile the fire was flaming in high billows behind him, and the smoke, black and thick, filled the sky. Clayton began to be somewhat alarmed. In desperation he had entered this grassy land and had fired the grass, but he seemed not to have bettered his position, in spite of the blaze. Indeed, if the fire ringed him in, or overtook him, his situation would be worse than before. Though his face paled, he spoke hopefully to the girl who clung to him. The Blackfeet were still unseen; and, indeed could hardly have been seen now through the pall of smoke and the billowing flame, even if they had come riding straight down from the hills in chase. The horse was a gallant animal, and was standing up splendidly to the work, yet the strain was beginning to tell. Its sides were heaving, its head was sunk low, and its whole body was covered with a white lather of sweat. Its nostrils gaped wide and red as it plunged onward. If the horse had been fresh, the hopes of Bruce Clayton would have mounted high, for its gait was faster than the running advance of the fire; but the horse was becoming exhausted. It had been tired even before he encountered the young Indian chief, and since then he had driven it hard. Three miles away, and lying along the rocky rim of the cañon which held the river, was a long strip of woodland. On the other side were the hills. The open, grassy country lay straight ahead between these two. The speed of the fire, as it now pursued him, admonished Clayton that safety demanded he should not hold to the straight-ahead line. The fire would run on indefinitely, but the horse could not do so. The Indians were in the hills when last he heard them; and for that reason chiefly he turned the horse toward the distant fringe of timber. “We can make those trees without trouble, I think,” he said, encouraging the girl, whose terrified backward glances he had observed. “But the fire is coming very fast!” she said. “And we are riding fast!” “But it is gaining on us. The horse has lost speed in the last mile. The poor thing is exhausted.” “Still, I think we can reach those trees. We’ve got to do that.” The horse stumbled, bringing a cry from the girl; but righted, and galloped heavily on. Soon it stumbled again. Then before them they beheld a yawning rent in the earth, like a large and deep ditch. It was in fact a dry waterway, cut by rains that came in some torrential storm down from the hills. It was impossible to go round this gap in the earth.