"Whoever it was that fired might shoot again," replied End.
"Who was it?" asked Nort.
"That's what we've got to find out," answered Bud in a low voice.
"Could it have been either Snake or Yellin' Kid, riding back and breaking that bottle over our heads, to show what good shots they were?" asked Dick.
"No, I hardly think so," replied his cousin. "They're both good shots, all right, and they could have broken that flask from the distance it was broken. But they wouldn't throw a scare into us this way. Besides, they haven't any time to fool around. They have an all-night ride ahead of them."
"What makes you think the bottle was busted from some distance,
Bud!" Dick wanted to know.
"The way the bullet sounded," was the answer. "It was almost spent when it got here, but it had force enough to break the glass, and would have damaged us if it hit us. I thought whoever played that fool trick might try another shot, so I yanked you down, Nort."
"Glad you did! I might not have thought of it. But whoever it was doesn't seem to be going to shoot again."
"No," agreed Bud, after a little period of silence, during which no other menacing crack of a weapon was heard. "But we'll wait a little longer."
Through the fast-gathering darkness the boys looked out from their semi-hiding places across the valley. No wisp of smoke, and no movement of horse or rider was to be observed. And silence once more settled down on Happy Valley—not quite so happy as it had been. For, following the clearing-up of the mystery of the water supply, new and sinister events seemed pending for the boy ranchers.