A young woman discovers that her boyfriend is sleeping with her cousin Helen and goes to confront them at a dinner party, only to find out that Helen is dead and everybody is a suspect.A young woman discovers that her boyfriend is sleeping with her cousin Helen and goes to confront them at a dinner party, only to find out that Helen is dead and everybody is a suspect.A young woman discovers that her boyfriend is sleeping with her cousin Helen and goes to confront them at a dinner party, only to find out that Helen is dead and everybody is a suspect.