In the Paris suburb of Chavigny, Joseph Boussard (André Falcon) holds political office in the lead up to an election. When a campaigner for the opposition is killed, the respected Dr. Peyrac (Bernard Fresson) decides to contest the election. One of Boussard's aides obtains and circulates a doctored photograph of Peyrac's wife, Sylvie (Annie Girardot), engaged in group sex at the home of their friends, the Leroys. Peyrac calls for the authenticity of the photograph to be validated but is shut down.
The photographer who produced the fake is murdered; Peyrac is accused for the crime and imprisoned. Sylvie defends her husband with the assistance of Olga Leroy (Mireille Darc). Olga knows people in high places who could be affected by the scandal. Peyrac is released but the scandal has negatively impacted on his standing with his friends and his support of the community.
