There were anxious days that followed the appearance of the epidemic among the cattle of the boy ranchers. I speak of the cattle as their own, and they were, in a sense. For though, of course, Mr. Merkel really owned Flume Valley, and put up the cash to start the boys in business, he had determined that they should run the place as though it was their own. They must stand or fall by what happened. It was the only real way to start them in the way of becoming cattlemen, he decided. So, though the boys were young, possibly the youngest ranchers in that part of the west, they were in earnest and accepted all the responsibilities that went with the venture. Bud was very thoughtful those anxious days. There was hard work for all, since dividing the doubled herds into small units meant that each cowboy, including Bud, Nort and Dick, had to look after a certain number day and night. But no one shirked, even Buck Tooth working unusually hard in addition to doing the cooking. Though Indian braves are constitutionally opposed to labor, Buck Tooth made an ideal herdsman. Not as much time was spent in camp as had formerly been the case, as the boy ranchers and their older helpers were more often out riding herd. But occasionally many of them gathered at the tents to compare notes and "feed up," as Snake put it. His wound, received in the fight with the rustlers, had healed. "Some day we'll have regular ranch houses here instead of just a camp," Bud said, as he was riding back one day to look after the herd he had assigned to himself. "Oh, this isn't so bad," spoke Nort. "Real jolly, I call it!" added Dick. "If only the water supply keeps up, and no more epidemic comes, we'll be all right," Bud announced. "At the same time I can't be sure of either." This was true. Though the water flowed merrily on since the time the lads had penetrated the length of the tunnel, there was always an uneasy feeling, on the part of the boy ranchers and their friends, that it might stop at any time. "And when it dries up again," Bud declared, "I'm not going to be satisfied until I find out what makes it quit flowing!" "That's the idea!" added Nort. "We'll solve the mystery!" As the days passed, and no more cattle were found ill or dead from the epidemic, the hopes of the boy ranchers began to rise. Had they caught the malady in time? Could it be stamped out by the burial of the five steers? Time alone--and a longer time than had so far elapsed--could tell. Bud, Nort and Dick each had charge of a herd, the three bunches of cattle being pastured on adjoining areas of rich grass. But the distances separating them were not so great but that Bud and his cousins could exchange visits. And it was on one of these occasions that there occurred something which cleared up, in part at least, the mystery hanging over Flume Valley.