Psychological crime drama directed by Claude Chabrol. Successful professional Charles Masson (Michel Bouquet), married and with a loving family, has been having a secret affair with his neighbour's wife Laura (Anna Douking). Finding with Laura the outlet he needs for his sadomasochistic urges, during one liaison Charles goes too far and ends up strangling her. Unsuspected of the crime, and with no evidence linking him to the murder, Charles has apparently escaped justice. It soon proves impossible for him to escape the urgings of his own conscience, but when Charles confesses his responsibility for the killing to his wife and Laura's husband, he finds them strangely unconcerned.