Max (Michel Piccoli) is a former judge obsessed with seeing criminals brought to justice. The frustrations of the courtroom, where evidence matters more than guilt, lead him to join the police force. Independently wealthy, he uses all his official and personal resources to make criminals pay for their crimes. He hits on a scheme involving a prostitute (Romy Schneider) and her small-time criminal boyfriend (Bernard Fresson) in which he incites the boyfriend to carry out larger and larger crimes until he can arrange to catch him red-handed. While he has been using the prostitute to set up her boyfriend, he has also fallen in love with her.