"I'm afraid that doesn't mean anything," said Bud when he had signified that he, too, heard the ripple. "Dad said there were a lot of underground streams around here. This one must come from the little brook that flows through Smugglers' Glen. It takes a dip down under the rocks and comes to the surface again farther on."
"I guess you're right," admitted Dick. "It doesn't mean anything. But
I didn't know there was underground water in this section."
"Oh, yes, plenty of it," Bud added. "I've seen other places with rock fissures like this where you could hear water bubbling along beneath the surface."
"Then this goes into the discard," spoke Nort, meaning that it was useless to form any theory about the mysterious deaths if it was to be based on the underground streams.
"But we'd better get on to the cave mine!" cried Bud. "If those fellows are at their poison gas game again, it's likely that Sam Tarbell and the fellows we left on guard are in as bad shape as these cows. Darn the luck, anyhow!"
"That's what I say!" chimed in Nort as the three hastened to where they had left their ponies. "Just as we thought we were sitting pretty, with nothing to worry about, along comes this! Wonder how they worked the game, anyhow?"
"They must have got back in the cave—probably from the end where they ran out the time we chased 'em with our gas masks on," said Dick. "They sneaked up on our fellows, let loose a cloud of gas, put them out of business and then came down here to kill the cows."
"But that's what I can't understand," said Bud. "Why should they go to the trouble of killing cows? Cows can't spy on those gold mine jumpers. Cows can't get out any gold. It's all so useless, this killing of our beasts."
"I guess they're just natural devils as Billee claims," suggested Nort.
"But we'll pay 'em back!"
"You bet we will!" exclaimed Bud. "And now to the rescue! We've got to save Sam and his crowd if we can!"