Georges has Down syndrome, living at a mental-institution, Harry is a busy businessman, giving lectures for young aspiring salesmen. He is successful in his business life, but his social life is a disaster since his wife left him and took their two children with her. This weekend his children came by train to meet him, but Harry, working as always, forgot to pick them up. Neither his wife or his children want to see him again and he is driving around on the country roads, anguished and angry. He almost runs over Georges, on the run from the institution since everybody else went home with their parents except him, whose mother is dead. Harry tries to get rid of Georges but he won't leave his new friend. Eventually a special friendship forms between the two of them, a friendship which makes Harry a different person.
Antoine Rivière, a highly-reputed psychoanalyst, is visited by a new patient, Edouard Berg. When Berg claims to have killed his own wife, the doctor suspects he is a compulsive liar. How could he know that he has been caught in a trap and it's already too late for escape?
In the middle of the night, someone brings Ivan's body home to his wife and his sad-faced, jug-eared son. Through flashbacks, the film discloses the relationships among Ivan and his brother Alex, a cop with a cleanliness fetish; siblings Juliette and Jimmy, Ivan's partners in a seedy nightclub; the love triangle of Alex, Juliette, and Marie, a professor of philosophy; and of Alex and his nephew, Ivan's dour, stoic son. Ivan's death changes every relationship.
The night of August 24, 1572, is known as the Massacre of St. Bartholomew. In France a religious war is raging. In order to impose peace a forced wedding is arranged between Margot de Valois, sister of the immature Catholic King Charles IX, and the Hugenot King Henri of Navarre. Catherine of Medici maintains her behind-the-scenes power by ordering assaults, poisonings, and instigations to incest.