The secret of the old mill

by Franklin W. Dixon

"What are you going to do about this note?" she asked.

The detective shrugged.

"Ignore it, of course."

"But they may harm you."

"They may try. They won't be the first ones who have tried to frighten me away from a case."

"But they must be right in Bayport, to deliver a note like this."

"I've suspected all along that their headquarters were here. Don't worry, Laura. I'm not afraid of them."

"But I do worry. They're desperate men. They'll stop at nothing."

Fenton Hardy laughed.

"It isn't the first time I've been threatened. It's only a bluff. I'll stay right on the case—although so far I haven't been able to make much progress on it.