In 1700 in Nevers, France, a skilled swordsman named Lagardère (Daniel Auteuil) challenges Duke Philippe de Nevers (Vincent Pérez) to a friendly duel in order to learn his secret lethal maneuver known as the "Nevers Attack". Nevers agrees and quickly dispatches the upstart whom he soon befriends. Nevers learns that he has a "son" by Blanche de Caylus—a fact previously concealed by his cousin and would-be heir, the wicked Comte de Gonzague (Fabrice Luchini). That night Nevers escapes an assassination attempt by Gonzague's men.