Dick led the way out of the cave, flashing the light as he walked.
All four blinked when they found themselves out in the sunlight.
"Now, which way are we going, David, little giant?" demanded Tom good-humoredly.
Now that he was put to it, Dave had to confess that he didn't know.
"Let's make a swift, thorough search all around here, and see if we can find any footprints not made by ourselves," Dave suggested rather weakly, at last.
This was done, and faithfully, for, now that they were out in the sunlight again, the interest in the mystery began to return. It grew stronger as they searched. At last, however, after more than an hour of fruitless effort that offered not an atom of promise, even Darry was willing to give it up for the time, at any rate.
"Let's keep on walking along the slope, then," Dick suggested, "until we come in sight of the canoe."
As they walked along they came to a brook that, at this point, was nearly the width of a creek. The water ran noisily down over the stones, save here and there where there were deep pools.
"It's narrow enough, at one point below here, to jump over," Dave volunteered.
"Thank you," replied Dick, "but just at present I'm not for jumping over this brook."
"Well, then, what on earth does interest you?" Dan asked. "This isn't the first time you've seen this stream. You passed it down by the lake, though down there it runs more smoothly."