Then, unfortunately, Snap himself looked down through the ribs of that skeleton bridge. It was getting dusk now, and he could not see very clearly; but below he could hear the roll of waters amongst the boulders, he could see the tops of trees far below him, and occasionally a white flash of foam where the river dashed against a black rock. He didn't like it, 'you bet,' as he said afterwards, 'he did not like it,' and the more he looked the less he liked it. For some reason, unexplained, his knees at this juncture acquired an unhappy knack of knocking together, and grew weak and uncertain. With a start he pulled himself together. This would not do at any price. There was another hundred yards of bridge to traverse, and he hardly thought, if the train was 'on time,' that he would be able to coax that steer across before the train reached the bridge. At that moment a roar sounded behind Snap--the roar and rattle of a huge engine, and then a piercing shriek from the steam-whistle--such a shriek, so shrill, so wailing, that it sounds among the lone peaks of the Rockies like the cry of some tortured spirit. Snap's heart turned to stone in that awful minute, as the red light rounded the bluff not a hundred yards from the head of the bridge, and rushed towards him. Then the blood came back to his cheek, and the strength to his arm. Death was staring him in the face. Unless he DID something, he had not ten seconds to live. He would have raced for the other end of the bridge, but his brain was keener now than ever in his life before, and he knew human speed would avail him nothing in the time allowed him. In another few seconds the cow-catchers would sweep him off the track and hurl him down, down, rushing through the air over that narrow edge to the sharp, wet rocks below. The rails themselves were so near the edge of the bridge that a man could not stand outside the rails and escape. The foot-board of the train would sweep him down, or the wind from the engine blow him into space. There was only one thing to be done, and with a muttered prayer he did it. Dropping on his knees in the middle of the track, he seized a beam with both hands, lowered himself through the opening, and hung by his hands, dangling over the depth below. If he let go it meant death. His muscles were strong, his grip desperate, but could he hold on when the timbers rocked beneath the great mass of wood and iron which was even now upon them?