A week before her wedding, Agathe Plichard, a pretty young woman of mixed race, is found drowned in the Creuse river. The police treat the case as an accident but her fiancé, Félix Bricourt, is convinced she was murdered. He decides to investigate by himself, despite the wishes of his family, a wealthy dynasty of the region. Won over by Félix's resolve, police inspector Carole Levasseur also decides to find out the truth. The murder of an independent journalist changes the course of the investigation, stirring up the past and unveiling the forgotten "Children of the Creuse" affair.

Pierre has been happily married for fifteen years and a good father. Still in love with his wife, he enjoys his wife and family and is content. One evening, he meets Elsa at a party and are immediately attracted to each other. Fifteen days later, they happen to meet again and the mutual attraction turns into infatuation. But his love for his wife and Elsa's rule about not dating married men prevents them from taking the next step. Instead, they fantasize about each other, and soon the fantasies mingle with the reality.