Mathieu, a piano virtuoso, goes home to help his brother Paul to take care of their sick mother. Paul is into reenacting old battles, dressing up and getting into character, even dueling if necessary. Mathieu gets involved in this world and play becomes real.
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.