Super-sleuth Philo Vance faces the zaniest case of his career when Gracie Allen "helps" him try to solve the murder of an escaped convict. As she attempts to clear the name of a friend accused of the killing, her wacky, scatterbrained ways constantly impede the investigation.

Lady Alyce Marshmorton must marry soon, and the staff of Tottney Castle have laid bets on who she'll choose, with young Albert wagering on 'Mr. X'. After Alyce goes to London to meet a beau she is restricted to the castle to curb her scandalous behavior. Albert then summons Jerry to Alyce's aid in order to 'protect his investment'.