The Secret of the Old Mill

In The Secret of the Old Mill, the third gripping installment of the Hardy Boys Mystery Stories series, Frank and Joe Hardy uncover a sinister counterfeiting operation hiding in plain sight—and the key may lie in the shadows of an abandoned mill.

When a stranger passes off a counterfeit bill at the Bayport train station, the Hardy boys quickly become entangled in a baffling case involving fake money, secret messages, and suspicious characters lurking near the old mill outside town. As they follow the clues, the brothers begin to suspect that this quiet, rundown building holds more than just memories—it might be the center of a dangerous criminal enterprise.

But when their friend Chet Morton goes missing, the investigation turns urgent. Facing hidden passageways, coded warnings, and a mastermind who will stop at nothing, Frank and Joe must race against time to uncover the truth and put an end to the mystery before someone gets hurt.

Filled with fast-paced action, classic sleuthing, and smart teamwork, The Secret of the Old Mill is a timeless detective novel that continues to thrill fans of children's mystery books, adventure stories, and classic young adult fiction. A must-read for lovers of the Hardy Boys, Nancy Drew, and retro whodunits.