ng about in the thicket
immediately in front of them.

A low whistle cut the air, and then the creepers parted and a man's head
and shoulders appeared. Ned and Jimmie crouched lower in their dent in the
grassy hill.

The man emerged from the thicket and stood with the others, tearing
clinging vines and leaves from his clothing as he did so.

"What is wrong?" a voice asked. "There has been no explosion."

"The fuse was wet," was the reply.

"Then why didn't you go back and fix it?" demanded the first speaker. "The
sooner the job is done the better."

"I heard some one stirring in the jungle," was the reply.

"A nice man to be given such a task," roared another voice. "You must go
back."

"You've landed the plotters, all right," whispered Jimmie. "I'll bet
there's plenty more bombs like the one you have, waiting to be tucked
under the Gatun dam. Gee! I'd like to take a shot at them gazabos."

Still standing in the moonlight, only a short distance from the listening
boys, the three men argued in low tones for a moment. It was clear that
the man who had placed the bomb was refusing to obey the orders given by
the others.

"I'm not in love with the job, anyway," the fellow snarled, "and you may
do it yourselves if you want it done to-night."

The others did not appear to relish the murderous job they were urging the
speaker to undertake, and in a few moments the party moved around the base
of the hill and then struck for the higher ground by way of a gully which
cut between two elevations.

When the boys, mounting the breast of the hill and crouching at the
summit, saw the men again, two were making for the cloud of light which
lay over the workings while the other was following the crest of the hill
toward the east.

Presently the two swung down into a valley, and then twin lights like
those of a great touring car showed over a rise.

"What do you think of that?" asked Jimmie. "There must be a good road
there."

The car came on a few yards after the lamp showed, and the two men
clambered aboard. In five minutes the motor car was speeding toward
Gatun.

"Two for the city and one for the tall timber," Jimmie snickered, as the
car moved out of view. "There's the solitary individual watching them from
the summit."

As the boy spoke the man who had laid the bomb so unsuccessfully faced
away to the east and disappeared down the slope. It was not difficult to
keep track of him, although the necessity for con