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.