Neither of the three men had ever been on this part of the river before; but Clayton recalled what some of his former associates, the outlaws, had told him of an “underground river,” called the Bitter Water, that cut through a cañon in these mountains. He knew now that he was afloat on that underground stream. What the result would be he could not foretell. But he recked not of the danger. If Lena Forest had been taken through it, he would not hesitate to follow; no, not even if it led him to death. “Hold hard!” Buffalo Bill shouted, for the canoe was jumping and bucking like a wild horse. “Hold hard!” Pawnee Bill could not use his eyes to much advantage in a search of the black walls; and as for the young man, he had all he wanted to do to cling to his place as the canoe flew on. The darkness became like ink, showing that the river was here completely walled in; and it seemed to him that the water grew rougher, while certainly its roar was much louder, due to its closed-in condition. The roar was thunderous now. But on the canoe went, through the darkness and the howling noise, whether to destruction, or to be guided through to safety, Bruce Clayton could not tell. CHAPTER XXV. AGAIN A PRISONER. Lena Forest had been recaptured by the handsome young chief, Lightfoot. By hard riding, he and a comrade had circled round the eastern end of the line of fire, only to find their horses exhausted by the terrible run and themselves driven back by the flames. They abandoned their horses, and when the fire died down along the edge of the rocky hills, they set out across the burned area on foot. They had become separated from the other Blackfeet, also, in the wild chase. Lightfoot had lost sight of the young Indian girl, Wind Flower. His present companion was a young brave who stood ready to yield him obedience as a chieftain of the Blackfoot nation. With this young warrior, whose name was Red Antelope, Lightfoot came finally to the gully. They could not leap it because of its width, and this fact induced the young chief to think that perhaps the horse of the white man had not been able to get across. To break their trail, Lightfoot descended, with his companion, into the gully; and then they went on down, until they reached the point where Clayton’s horse had fallen. They saw the girl bending over the prostrate youth, and the horse lying dead. She did not see them, so wrapped was she in her grief and in her frantic efforts to restore life to the seemingly inanimate form of her hero. Under the conditions, they had no trouble in approaching her and making her again a prisoner.