During Valentine's Day holiday, while keeping an eye on a scary ivy-covered house while the woman who lives there is away, the Calender Club kids discover a gang of clever thieves and a plot to kidnap Cupid.
Casey, Leon, and Dottie, The Calendar Club detectives, won't let their babysitter stop them from using their detective skills to find and prevent a cat bugler set to steal money and jewelry at the town's New Year's Eve party.