and while diving Fred noticed a peculiar knocking sound under
water. He called the attention of the others to this, and each cadet
heard it quite plainly.

"It must come from the same place as those other noises we heard,"
declared Jack.

"I move we make a real investigation!" cried Andy. "Let's ask for a
day off and scour the woods thoroughly."

"That's the talk," cried Fred.

The others were willing, and received permission to go out two days
later, the party consisting of the four Rovers and Gif and Spouter.
They took their lunch with them, and also some canteens of water,
expecting to be gone until nightfall.

There was quite a discussion as to how they should start the
investigation. Some wanted to go along the base of the cliff at the
water's edge, while others were for making their way through the
forest. The latter suggestion prevailed, and they started near the
point where Randy had first heard the strange noises.

The young cadets tramped hither and thither among the trees and over
the rough rocks for four hours without coming upon anything unusual.
They stirred up a number of birds and small animals, but that was all.

"Looks like a wild-goose chase," remarked Jack, when they sat down to
rest and to eat their lunch.

The climbing over the rocks had been very tiring, and all of the lads
were glad after eating to take their ease for a while.

Randy was resting on his side, wondering whether it would be worth
while to play a trick on Gif and Spouter, who were but a few feet
away, when a movement among the trees at a distance attracted his
attention. He sat up, and as he did so felt certain that he had seen a
man moving along.

"Listen, boys!" he cried in a low voice. "There is some one now!"

"Where?" came from the others, and all aroused themselves on the
instant.

Randy pointed out the direction, and, gathering up their things, the
cadets hurried off to where he had pointed. There, sure enough, was a
man plodding along with a bundle over his shoulder. He was a short,
thick-set man, and wore a heavy mustache curled up at the ends.

"Let's see where he goes," said Jack. "Maybe he'll take us to that
place where the noises come from."

They followed the man without his being aware of their presence. The
fellow climbed over and around a number of rocks, and then pursued his
way past a dense clump of bushes. Then, of a sudden, he disappeared
from view.

The cadets were amazed, the more so after t