The Secret of the Old Mill, The Hardy Boys Mystery Stories. Author: Franklin W. Dixon. 212 pages. Hardcover, no dust jacket. Publisher: Grosset & Dunlap, copyright 1927, printed in the U.S.A. circa 1952-1956.

The 1952 printing has orange and white endpapers, and a 4-page info ad for the Rick Brant Adventure Series at the end of the book.

Synopsis: Frank and Joe Hardy become involved in a complex mystery involving counterfeit money, a mysterious old mill, and a series of suspicious characters connected to a new Hydrolectric Company in town.

The story begins when the boys encounter fake twenty-dollar bills circulating in Bayport. Their friend Chet Morton is nearly cheated with counterfeit money, prompting the Hardy brothers to investigate. At the same time, their father, the famous detective Fenton Hardy, is secretly working on a federal case involving a large counterfeiting ring—though he won’t reveal details to the boys.

Clues repeatedly point toward an abandoned mill on the outskirts of town...

As the boys dig deeper, they uncover a network of criminals who are using the mill as a front for producing counterfeit bills. Their investigation takes them onto the waterfront, along the river leading to the mill, and through confrontations with thieves and con men tied to the operation.

Condition: The book is in overall fair shape.  The first four pages are separating from the binding (see closeup photo below), and the binding and spine overall are in fair shape with some wear and looseness.  The book's covers have wear along the spine. The inside pages are in very good condition (see photos).