Sickened at the meaningless bloodshed between Catholics and Protestants in the Wars of Religion, the Count of Chabannes decides to desert. Captured by bandits who are about to hang him, he is rescued by his former pupil, the Prince of Montpensier. The two ride to the castle of the Mézières family, where the prince's father has been negotiating a bride for his son. This is Marie, who is on intimate terms with her childhood friend, the powerful Duke of Guise. When Guise is outraged to hear that Marie is to be given to Montpensier, Chabannes tries to reconcile the two fiery young men who have drawn swords.