Marceau Léonetti (Lino Ventura), a competent and energetic officer stops by chance the son of an influential lawyer driving under the influence of alcohol. A few months later, the lawyer falsely accuses Léonetti as being violent and incompetent. As a result Marceau is transferred to a small police station, where he meets young and beautiful Jeanne (Marlène Jobert). Soon they are faced with a tough investigation.