Young police inspector Corinne Levasseur interrogated a dealer without the judge's consent. Following an indiscretion of her lover, the substitute Berthot, Corinne is transferred to a small town in the North who lives under the thumb of a rich industrialist and his family. He is given subaltern tasks. Intrigued by the strange death of a teenager, she stubbornly leads an investigation that allows her to trace the chain of a child prostitution network in which are mixed a notable and his son-in-law. A young investigating judge decides to investigate the case, but he is the victim of pressure ....