What mystery did it hide? Was there any mystery? Was the whole message just a hoax?

He could not believe this. In any case, Hanleigh knew something about the mysterious Sparewell—else how did he get possession of the notebook? And in this respect alone the mystery was worth following up.

That evening, the Hardy boys and their chums were gathered around the fire. Chet and Joe were playing checkers. Biff had rigged up the punching bag, had donned his boxing gloves, and was making the bag drum in a lively manner. Frank was still studying the cipher, wondering if there might not be some little clue he had missed. Once in a while he referred to the pages of the notebook again.

It was growing colder outside and the boys had to keep a roaring fire in order that the cabin should be warm enough. The wind was rising and there were fitful slashes of snow against the windows.

“More dirty weather!” growled Biff, dealing a particularly vicious blow at the punching bag.

“Seems it’s done nothing but snow since we came here,” said Chet.

“It’s your move,” Joe reminded him.

Chet moved his checker and Joe promptly captured it, with a king as well.

The scene was peaceful. The boys would have been interested if they had known of what was happening in a little house in Bayport just then.

Hanleigh was preparing to return to Cabin Island.