The other scout kept his keen eyes busy in searching the walls and the shores and the stream ahead, lest the canoe should be run into an ambush. Soon the speed of the canoe ought to have satisfied even the wild anxiety of the young lover. The current had quickened again into cataracts that tossed and hurled the little craft about as if it were but an eggshell. The rate at which it flew on was enough to take the breath of the canoemen. Buffalo Bill poised and dipped his paddle with rare skill. It needed a good eye, a strong arm, and a steady brain, and he had all three. A rock reared itself in the center of the stream, and the current threw the canoe at it, as if to split it in two; but the unerring paddle swept the canoe to one side, and the dangerous rock shot past, with the water boiling white round and over it. A swift turn of the channel threw the canoe over against the wall of dark granite, as if to smash it there; but again the paddle urged it back into the middle of the boiling water, and held it there, as it sped on with arrowy swiftness. The cañon walls came closer together, pinching in, confining the water, and increasing the strength of the current. The waterway grew dark, as if enveloped in twilight; yet the white water swirling and boiling over and round sharp, up-thrust rocks could still be seen, wherever the rocks lifted themselves like hungry teeth. Around these, dipping and paddling lustily, the scout guided the dancing canoe. Clayton was hanging on as if for dear life, for now and then the canoe rose into the air and gave a leap as it took some cataract and shot on, the waters roaring about the canoe in a fearful din. At last the cañon opened, brightening ahead; and soon the worst of the perilous way was past, with smoother water opening before them. Pawnee Bill watched keenly for some indications on the shore that would show that the captors of the girl had left the river with her here. The boat moved on more slowly, to enable him to do this; but no signs of such a disembarkation were to be seen. Soon before the canoe loomed the darkness of another narrow reach of the cañon. “Shall we go into it?” the scout shouted. “Yes,” said Pawnee Bill. “They haven’t landed here; so they must have gone on.” The canoe shot, with dizzying swiftness, toward the dark opening, the current again running beneath the keel with race-horse speed, requiring, for the safe management of the canoe, all of Buffalo Bill’s marvelous skill with the paddle. It was seen, when they were fairly in the dark opening, that here the cañon roofed itself overhead; so that the river ran through a black tunnel, making thus practically an underground river.