Fay Allison is getting married in a few days to Dane Grover. Her roommate, Anita Bonsal, is having a clandestine affair with a married man, Carver Clement. When Aunt Louise arrives early the next morning to be with Fay, she finds Fay and Anita both appear to have been drugged. Louise calls her friend Perry Mason to help decide what to do. Perry and Della discover the key to another apartment in Fay's purse and go upstairs to investigate. They arrive to find Carver Clement dead in the apartment. Fay Allison is accused of the murder when the police find her fingerprints on a glass in the apartment.