hard
work, but they were in deadly earnest, and did not let the vines and
brushwood deter them.

"Now, the question is, How are we to scare them?" said Dick, after they
had regained the trail, well in advance of Sid Merrick and his
followers.

"Let us play ghosts?" said Sam.

"We might black up and play niggers on the warpath, with big clubs,"
suggested Tom.

"And get shot down," interrupted Dick. "No, I think the ghosts idea is
as good as anything. Quick, take off your coats and tie your
handkerchiefs over your faces."

The boys had on light-colored outing shirts, and these, with the
handkerchiefs over their faces, made them look quite ghostlike in the
gloom under the trees.

"Now, when the time comes groan," said Tom. "Ghosts always groan, you
know."

"And let us order them back," added Sam.

"But be sure to do it in very ghostlike tones," warned Dick. "If our
voices sound a bit natural they'll get suspicious at once. If they come
for us, or shoot at us, drop behind the rocks and run into the woods."

It must be confessed that the boys were doubtful of the success of
their ruse. Yet they felt they must do something to hold the
treasure-seeking party in check, at least until morning. With the
coming of daylight they could signal to the _Rainbow_ and with the
aid of those on the steam yacht probably rout the enemy.

The Rover boys advanced along the trail until they reached a spot they
deemed favorable for their purpose. Then Dick gave his brothers a few
more directions.

Presently they saw the rays of the gas lamp and the lantern in the
distance. At once Tom set up a deep groaning and Sara and Dick joined
in.

"What's that?" asked Shelley, who was the first to hear the sounds.

"Sounds like somebody in distress," answered Sid Merrick.

"Thought you said there was nobody on this island?" came from Cuffer.

"Didn't think there was. Maybe it's some native who----"

"Look! look!" screamed Tad Sobber and pointed ahead with his hand.
"What's that?"

"What's what?" asked the men in concert.

"There--that thing bobbing up and down over the rocks?" And Tad Sobber
trembled as he spoke. This lonely walk through the darkness of the
forest had somewhat unnerved him.

"That's strange," muttered Merrick. "It's groaning!"

"It's a ghost!" screamed Tad, and shrank back, as did Cuffer and
Shelley.

"A ghost?" repeated Sid Merrick. "Nonsense! There are no such things as
ghosts."

"It cer--certainly looks l