Clay checked himself with the sentence half finished.
“Suppose,” he mused, “just suppose, there should be a subterranean stream running in from under the hills—let us say from the north. That would be a channel, wouldn’t it? And it might be a lost channel at that! Why didn’t I think of that before.”
The boy was so full of the thought, so enthusiastic over the thing it might mean, that he concluded to make a quiet investigation on his own hook, saying nothing to the others regarding the matter.
“What was it you said about some underground stream?” asked Captain Joe. “You started in to say something about it and then stopped abruptly.”
“Oh, it just occurred to me that there might be an underground river somewhere around here, but I guess that’s just a dream. There couldn’t be any river, you see, for the ground is rocky, and there seems to be no place for an underground stream to get its supply.”
“No,” the old captain agreed, “there can’t be any underground stream that’s a sure thing. If there are caverns they are dry.”
Clay chuckled to himself, and went into the cabin after Alex.
“Come on, Redhead!” he cried catching the boy by the arm. “We are now going ashore to dig up the lost channel.”
“That’s a nice pleasant little job, too!” Alex declared.
“Well, come on,” Clay insisted. “We’ll go over and make a start, anyway. We may be able to find out if the outlaws are really here.”