"We are afraid they are up to some trick." "A trick ?" repeated Sam.

Then he gave a gasp.

"The room--isn't there a back door, leading out to the shed ?" "I don't know," answered Dick.
"I'll run and see." Sam was gone less than two minutes when they heard a cry, and then he pounded on the door they had so carefully guarded.
"There is a back door and it is wide open.

The men have gone!" was his dismaying announcement..