"Gee!" exclaimed Jim, "suppose a bowlder has rolled onto the track just ahead. It might happen easy enough too." Just then, Bill Sheehan, the fireman, touched Jim with the end of his shovel to call his attention to something they were coming to ahead. Jim saw a jumbled heap of freight cars half in the stream and half out, and a little ways further on was the rusty ruin of a once powerful locomotive. Jim nodded to the fireman. "Something has been doing there," he yelled, but the words were blown from his lips and lost in the roar as steam disappears in the air. Jim took a look at his friend, the engineer. He was alert and intent, ready for any emergency, and Jim felt a sense of absolute confidence in his friend's skill. After a ten mile run, the canyon began to broaden out and there were other trees besides the solemn pines. A sense of impending danger came over Jim. He had experienced it many times before and whether it was an ambush of Indians, or the plans of some band of outlaws it had rarely betrayed him. It was something in the air; a vibration that the human nerves are as conscious of as a dog's nose is cognizant of the scent of some wild animal. Jim turned and looked at the engineer, who nodded back at him for a second, with a look that indicated there was business ahead; then his eyes were fastened on the track again. Jim took out his watch and saw that it was a quarter to two. It brought a quizzical smile to his face. Time and again he had noted the fact that it was just about this time that an attack was sure to come. It sent a thrill through his nerves for he felt that they were rushing straight to a crisis. Much depended on the three men in the engine, for there were many helpless women and children on the train for whose safety they were responsible. Jim noted that the country through which they were going was well suited for the purposes of the bandits desiring to hold up the train. On either side the walls of the mountains rose at the distance of only a few hundred yards, covered with dark pines and huge rocks showing here and there on the bare fall of some precipice. Between the foot of the mountains and the track was rugged ground, with large bowlders scattered here and there. Clumps of trees and bushes and numerous gullies could be discerned. It was just the country for a surprise of this kind. Jim stepped down from his narrow seat and got his hands thoroughly warm and pliable, took off his coat and folded it neatly on the seat and stood with his revolver in hand, seeing whether its action was all right. He was a stalwart figure indeed, dressed in his characteristic regimentals, with a thick, tight fitting sweater of blue, pants of the same color, and a new sombrero of a dark hue, for the old one had been battered and worn out of all semblance to a hat, and he was obliged to give it up, though it was like parting with an old friend.