In order to make a thorough examination it was decided to take food and water enough to last the expedition at least two days. It was easy to traverse the tunnel in one day, as the boys had proved. But Old Billee counseled a slower trip. "I wish I could go with you," said Mr. Merkel to the boys, when the time came for the start, "but I have a shipment of steers to get off, and I want to keep watch of this epidemic. It begins to look as if we had gotten the best of it, but I'm taking no chances." "Oh, we'll make out all right, Dad," spoke Bud. "Though we would like to have you with us. And when we come back we'll either settle, for good and all, this fight for water, or we'll abandon Flume Valley!" "I'd hate to see you give it up," said the ranchman. "It is an ideal place to raise cattle, with the water here. But without it, of course, there's no use thinking of it. Well, good luck to you," he called, as he turned to go back to Diamond X proper. As he had said, there had been no further outbreak of the epidemic among the cattle of the boy ranchers. The steers which Pocut Pete had cut, injecting into them the pus and germs, died, however. And there were more of these than Bud and his cousins had counted on. But if they lost no more than this half-score, and could get the water back, all might yet be well. The water in the reservoir had gone down several feet when the expedition started into the tunnel. Much of the fluid had to be drawn off to water the thirsty cattle, for it was the height of summer now, and the heat, in the middle of the day, was terrific. But there was still enough of the supply to last for several days. Then, if Bud and his companions could not discover the secret of the stoppage, and get the water to running again. Flume Valley would have to be abandoned. "Well, I can't see that we can do any more," spoke Bud. "No; you've got things as well fixed as possible," agreed Old Billee. "Can't tell when you'll see us again," said Dick to the remaining cowboys gathered about the reservoir end of the tunnel to see the expedition start in. "Well, good luck, anyhow!" came the answer. A number of punchers had been sent over to Flume Valley from Diamond X and Triangle B to replace Yellin' Kid, Billee and Snake Purdee who were to accompany the boy ranchers. Suddenly Yellin' Kid broke into song: "Leave me alone with a rope an' a saddle, Fold my spurs under my haid! Give me a can of them sweet, yaller peaches, 'Cause why? My true-love is daid!" "Oh, give us something cheerful!" laughed Bud, as the cowboy seemed about to start on another verse. "That's cheerful enough for this occasion," retorted Yellin' Kid. "Wait 'till you hear me howl in that tunnel." "Don't!" begged Dick with a laugh. "It echoes so you'll bring the roof down!"