 Marie Morgan (Ginger Rogers) takes her flashlight and key and opens the door of an old, dark and shuttered, overgrown with decay abandoned house. She is amazed to see on a cobweb-covered table, a new telephone, and as she enters the dining-room, where rats are gnawing the decayed remains of a sumptuous feast laid out years ago for thirteen guests, she is also surprised to find that electric lights have been installed. She sits in the thirteenth chair and resconstructs the scene of thirteen years before, when she, as a young girl, sat at the side of her father (Charles Meecham) who died at the table after reading a mysterious will. Outside two people climb out of an unlighted car and enter the house. Screams pierce the night air, and her cab driver (Harry Tenbrook) goes for the police. The police find Marie dead at her place at the table. Police Captain Ryan (J. Farrell MacDonald) calls in criminologist Phil Winston (Lyle Talbot) to assist him in the investigation. Police officers bring in Harold  Bud  Morgan (James Eagles), brother of the girl, and his friend, Thor Jensen (Eddie Phillips), both also guests at the fatal meal thirteen years before. They identify the body and cast suspicions upon family lawyer Robert Barksdale (Robert Klein. ) Order are given to pick up Barksdale who is later found dead at his original place at the table. Winston is called, and as he arrives, police officers bring in Marie Morgan, the supposedly dead girl, who explains that she was frightened away by the screams when she was there and has just come out of hiding. Winston determines that a double was substituted for her at the table, and takes her to his apartment where he persudaes her to call the surviving members of the dinner to come to his apartment. First to arrive is Uncle John Adams (Erville Alderson), who Marie describes as mean enough to kill anybody, followed by Aunt Jane (Ethel Wales) and Uncle Dick Thornton (Phillips Smalley) and their daughter Marjorie (Frances Rich. ) Harold and Thor also arrive. Finding them unwilling to assist and inclined to make a joke of the whole affair, Winston orders their confinement, but later has them released with a police officer ordered to shadow each one. The trail leads back to the old house, when Marie is given a false message to meet Winston there. Winston rescues her from a secret room and the clutches of the killer, and finds that the motive had been the attempted theft of a combination in her possession which unlocked a vault containing keys to a safe-deposit box disclosing her as the beneficiary of a will made prior to the dinner party 13 years before.