Even Merritt and Tubby showed that they were surprised to hear Rob speak in so positive a way, when it was plainly to be seen that the men on the hillside were becoming bolder, and apparently getting ready to rush the defenses of the rebel force a little later, after they had covered more ground. "Show your hand, Rob," said Merritt; "you're holding something out of sight, or you wouldn't talk like that. I know your ways; what's doing?" "Listen, and you'll hear the rebels cheering right now!" said Rob. "Yes, that's so," Andy replied; "but then they're ready to yell if anything happens. When that Federal lost his hold and fell about five feet, scrambling around like a squirrel that had missed its jump from one limb to another, they whooped it up till you'd thought the fight was won! What are they cheering for now, Rob?" "Lopez has told the captain, as I made him promise to, when things began to look kind of gloomy all along the line; and they're passing it on," Rob observed. "Yes, that's all very fine, but passing what along?" demanded Andy. "Now that the cheering has let up for a few seconds, and the Federals have stopped firing to puzzle out what the row means, suppose you boys trim your ears, and see if you don't get some sort of sound that surprises you!" "Great Cæsar! that rumbling must mean a train somewhere, Rob!" ejaculated Merritt excitedly; while Andy chimed in: "Does it, Rob? And did you glimpse it coming when you were away up yonder on the peak of the rocks?" "Yes," replied the scout master with a laugh, "through my glasses, away off toward the south. And, boys, that train is just loaded down with rebel soldiers coming up from Chihuahua to get after the raiding parties of Federals that have been burning bridges and destroying railroad stock on the Mexican Central here!" "And you didn't whisper a word of it to us, Rob, all this while?" cried Tubby, with a reproachful look on his beaming face. "Why, you see, I didn't want any one to have false hopes," Rob told him. "How could I tell whether that train would get here in a week? The track might be all torn up on the other side of the burnt bridge. But I fixed it with Lopez that he was to tell the captain when he saw me wave my red bandanna handkerchief over this rock; and you saw me do that a few minutes ago." "When you first caught the rumble of the train, and knew it must be drawing near on the south side of the river?" interjected Merritt. "That's what happened," Rob replied. "But see here," Tubby insisted, "how are they going to help us if that same train can't cross on the steel girders of the burned bridge? You don't reckon it can do that, do you, Rob?" "Certainly not, Tubby," replied the other, "but that isn't going to keep the men from getting over. You'll find some of them crossing like cats on the remains of the bridge. Others may wade the river, which doesn't appear to be very deep from what I saw of it."