Louise and Jean Dana's new friend, Edith Darrow, invites them to stay at her home for the weekend. While the girls are touring the property, they discover a hidden stash of objects in the barn which appear to be linked to Ed Carillo, a man wanted for swindling a real estate agent. Louise and Jean spend the night in the barn, hoping to discover who left the items in the barn. During their vigil, an injured man stumbles into the barn. The girls go to the main house for help and discover that Edith has disappeared and the house has been ransacked! What could have happened?

The mystery takes several more strange turns when the girls meet another person swindled by Carillo and then meet Carillo's mother, a nice person who is unaware that her son is a swindler. The girls work diligently on their complicated mystery, hoping to find Carillo, help the injured man, restore the stolen property to the rightful owners, and spare Mrs. Carillo the hurtful truth about her son.