"The one I _didn't_ shoot!" interrupted Bud. "I'm as sure I didn't hit him as I am that we four are here this minute. I know I fired too high!" "Unless the bullet hit a rock and glanced down," suggested Nort. "Well, yes, that may have happened," admitted Bud. "But if he was badly hurt he couldn't get away, as he did." "Could he have fallen into any hole or gully?" asked Dick. "We didn't look for that." "He might have," admitted the western lad. "But what I'm looking for, now, isn't that fellow, who may or may not be shot, but for the break in my flume--that's what I want to locate. Once I get the water so it's running back in my reservoir I'll feel better. For if there's a permanent shut-off we might as well move out of Flume Valley," he went on. "The cattle would just naturally die of thirst!" "Isn't there any water at all?" asked Nort, as he pulled his pony up sharply when the animal stumbled. "Not enough to water all the stock I aim to raise," answered Bud. "At the far end of the valley--away from our camp--the grass grows pretty well, for some rain does fall there once in a while. But there isn't a water-hole worth the name, and you know what happens to cattle when they can't get a drink!" "I should say so!" commented Nort, for he and his brother had seen some of the terrible suffering caused by animals having to be driven long distances without any water being available. "Then the pipe line is your only hope?" "That, and the ancient underground watercourse it connects with to bring water from the Pocut River," replied Bud. "You see, there's a sort of natural tunnel under the mountain, and this was once an old river bed. I suppose, or at least Professor Wright has told us, that once this tunnel was full-up with water. But there was a change in the direction of the old stream, and the water tunnel dried up. However, it didn't cave in, except in a few places, and we now use it to bring water to Flume Valley. There is really only a comparatively short length of pipe at either end, one end being where the water from the Pocut River enters, and the other where the pipe delivers the water to our reservoir." "How are you going to find the break?" asked Dick. "Or stoppage?" suggested Nort. "Well, I aim to ride over the mountain tonight," answered Bud, "and see if all is clear at the river intake end of the line. If it is, I'll know there must be a stoppage, or break, somewhere inside the old water tunnel." "How you going to find that?" inquired Nort. "Why, we'll get lanterns and ride through," replied Bud. "That's easy!" "Ride through an underground river!" cried Dick. "You can't!"