It is in Angoulême where she lives that Marie Jourdan invited her friend Paul Danceny to celebrate her 35th wedding anniversary. Unfortunately, the party is brutally interrupted by the police who come to arrest his son Alex, married and father of a little girl, for the murder of his mistress, a local journalist. This is only the beginning of the descent into hell for Marie, whose ideal family picture is increasingly lacerated by the revelations of the investigation. In addition to her son's extra-marital affair, Marie will discover that her husband has financed his new restaurant with dirty money belonging to his sworn enemy, a sulphurous businessman.