C'est important d'avoir un ennemi, c'est même vital.
In the middle of the night, someone brings Ivan's body home to his wife and his young son. Flashbacks reveal 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.