the reply. "I've taken a notion to look into that
apartment."

"And if they don't go away?"

"I'll wait until they do. It is probable that they do all their work at
night."

"Then you won't have to wait long," the boy replied. "It was growing light
in the east when we came down here."

Jimmie dropped off into a restless sleep after a time, and Ned sat there
waiting and listening, just as Frank, a short time later, waited and
listened on the porch of the cottage in the jungle. When the boy awoke it
was with a start of anxiety.

"The boys will think we're dead," he exclaimed.

"I hope they won't try to follow us," Ned whispered.

"If they do," the other said, "they'll find signs in twigs and stones all
the way along. The stone heaps point the way to this place, and give the
warning at the place where the stairs begin."

Reference was here made to Boy Scout methods used in the forest. For
instance, a stone with a smaller one on top says:

"This is the trail."

Place a stone to the right of this and the meaning is:

"Turn to the right."

One to the left means:

"Turn to the left."

A smaller stone on top of the other two, with none at the side, means: "Be
careful."

"I hope they will keep away," Ned went on. "It is a miracle, almost, that
we got in here without being discovered."

"What you think you'll find in there?" asked Jimmie.

"Something concerning the plot," was the reply.

It seemed a long time before the work in the chamber ceased, and Ned had
plenty of time in which to review the strange case he was interested in.
The transition from gay New York to that weird apartment seemed almost
like a whiff of fancy. Then he recalled the painstaking surveillance of
the fellow called "His Nobbs" on the way down, and smiled at the thought
that the plans he had made at first sight of the spy had worked out
remarkably well.

He had submitted gracefully to the surveillance, knowing that in time the
man who was following him would track him to his camp on the Isthmus. That
was the very point. He would not know where to look for the plotters, but
they would know where to look for him. He depended on them to send a man
to work him mischief, and reckoned on being able to follow that man back
to his principals.

This they had done. The men who had employed the spy on the ship had acted
quickly and had sent a bomb-thrower. Ned shuddered as he thought of the
risk he had taken that night in going to bed withou