An illicit affair leads to murder in Claude Chabrol's complex crime drama. When wealthy vintner Henri's (Jacques Dacqmine) mistress (Antonella Lualdi) is killed, the police suspect the milkman. But Laszlo (Jean-Paul Belmondo), the boyfriend of Henri's daughter, isn't sure the mystery is so easily solved. Could the real culprit be Henri's shrewish wife, Therese (Madeleine Robinson, in an award-winning performance), or his unstable son?