"Look at this, boys!" he cried; and then read the following:
"'Look over your safe very carefully. You may discover something to your advantage.'"
There was no signature.
"Who sent that?" came from Sam and Tom simultaneously.
"I don't know. It isn't signed."
"'Look over your safe very carefully. You may discover something to your advantage,'" repeated Tom. "Say! that looks as if somebody knew something about the robbery!" he went on, excitedly.
"We have looked over the safe a dozen times," returned Sam. "It hasn't furnished the slightest clew."
"We'll go over it again," broke in Dick, who had already left his desk and gone to the strong-box. He worked at the combination for a few moments, and pulled open the safe door.
"Maybe we ought to have a light here," suggested Tom. "It is rather dark in this corner."
"Wait, I can fix that," said Sam, and reaching for a droplight that hung over the desk, the youngest Rover commenced to unfasten the wire by which it was held in position. By this means he was able to shift the light so that it hung directly over the opening of the strong-box.