The boys gazed anxiously toward the west. Whitey thought of the three armed men, who now probably had handkerchiefs tied over their faces, and were lying in wait in the gully. Then of the oncoming train, with its unsuspecting passengers, and in the express car the bags of ore that were said to assay forty thousand dollars a ton. It wouldn't take much of _that_ to make it worth while for the bandits to hold up the shipment. Although the mist was getting thicker, it seemed singular that the train did not appear. The inaction of waiting was beginning to get on Whitey's nerves--and would have affected Injun's if he'd had any. At that, they had not been waiting very long, though they did not know it. "It must be getting near. I'll listen again," said Whitey. Whitey again placed his ear to the track, then looked up blankly. "It's stopped," he said, "Mebbe there's been an accident." Injun knew a good deal about plains and woods, and animals and birds, but was rather in awe of trains. He gazed at Whitey's face, which wore the same blank look as his own, and ventured no opinion. Two sharp, faint sounds came from the east--something between the crack of whips and the popping of corks. They were followed by three more. Injun knew about these. "Him shoot," he said. The startled expression on Whitey's face gradually gave way to one of understanding and disgust. "They came from the water tank," he said. "Don't you see? We're late, and what I heard was the train going the other way. Then it stopped, and they're holding it up." And Whitey sat down on one of the rails, thoroughly disgusted. For a while nothing was said. The disappointment was too great for words. The boys' chance for heroism had melted in the fog, which the mist had now become. Injun slowly put on his shirt. It was nothing but a garment now, no heroic rescue signal. "I'll bet that clock at the ranch was wrong. It always is. I might have known it," Whitey said dejectedly. The thought of the loss of the gold was forgotten in his disappointment at failure. "I hope no one was hurt--I mean none of the trainmen or passengers," he added. "But I guess not. Those bandits had the drop on them, and they couldn't have put up much of a fight. How do you suppose we heard those shots? We must be at least a mile from the tank. "Him fog," Injun answered. "Hear plain." And it is true that fog has a way of conveying sound. An idea brought Whitey to his feet with a leap. "What fools we are to be sitting here!" he cried. "We'll follow those robbers. The people on the train won't do that. They've no horses." Here, indeed, was a brilliant thought. The boys could track the bandits to their hiding-place, and possibly recover the ore. At least, they could return and report where the men had gone. There was a chance to distinguish themselves yet. In a moment they were mounted and dashing down along the track, toward the water tank.