Exploring ancient Rome, Mark and Penny Daring and their friend David are amazed at the majestic ruins of structures built thousands of years ago. Then, something unusual catches their eyes in the scenery--someone is following them! Little do they know, some thugs have planted phony money on Penny, hoping to falsely accuse Mr. Daring's business partner of making the counterfeit money.

With breathless prayers, the three teens barely outrun the criminals and flee to the authorities. Hoping for safety and time to relax, Mr. Daring takes them to his business partner's villa in the country. Then, while exploring an old watchtower on the property, the kids witness the kidnapping of Mr. Daring! And the kidnappers are the same villains who pursued them earlier!

Mark, Penny, and David are his only hope for a rescue. Stumbling along in the dark countryside, will they be able to locate the small shed where the kidnappers are holding Mr. Daring hostage? Can they save him without getting caught themselves?