d leaping over to the place where his chums stood.

"I thought you fellows were going to put a stop to that racket!"
complained Darry from the tent.

Dick Prescott's whole thought and effort had been centered on
the task of placing the location of that latest explosion.

"You fellows look after the camp," Dick called in a low voice
to those in the tent. "Come on, Tom and Greg!"

His two chums hurried to overtake him as the young leader rushed
off in the darkness. Prescott was traveling up the slope in a
direction that ran in an oblique line from the lake front.

"Are you sure it was just exactly in this direction?" whispered
Reade, as he reached Dick's side.

"In this direction as nearly as I could judge," Dick affirmed.

For some moments they traveled onward. Then they halted to listen.

"I don't know whether I'm any good at judging distances," Dick
whispered, "but it seemed to me that whatever exploded was not much
more than three hundred yards from camp."

"About that distance, I should say," Tom agreed.

"Then we've gone about as far as the place of the explosion.
Suppose we keep very quiet and listen."

"Ugh!" grunted Greg. "I hope the earth doesn't blow up under
our feet."

"Go back to camp, if you're nervous," smiled Dick, but Greg remained
where he was.

"I'm going out a little way and prowl," whispered Dick, pointing
in the direction he had chosen. "Tom, why don't you travel in
about the opposite direction?"

Reade nodded.

"Where shall I go?" asked Greg.

"You had better remain right here," Prescott whispered. "If you
should hear either of us yell for help then you could start in
the direction of the sound."

"Then I'll get into those bushes," whispered Greg. "When you
come back, come straight to the bushes, so I'll know that it's
one of my own crowd. If any strangers appear, I'll listen to
'em if they halt near here, or trail them if they try to go past
here."

Dick nodded. This seemed about the best that could be done.
Of course, back in camp, he had three more good and courageous
fellows to draw upon as added forces, but with such strange doings
afoot in the night it didn't seem wise to call the others away
from the camp. Above all, the camp had to be watched and guarded.

In half an hour Dick returned. He had found nothing to throw
light on the puzzle of the night. Tom was back already, having
beaten Dick to Greg's hiding place by about two minutes.

"We may as well