To prevent her brother Nicolas being called up by Napoleon’s troops, Christine promises to marry the man who goes in his place. Gontran de l’Ancre, a knight, takes over the duty, without, however, revealing his identity to Christine. As a token of her fidelity and a sign of recognition, she sends the unknown man a golden cross. Gontran, having been badly wounded in battle, gives the cross to the sergeant Bombardon who takes it to Christine. At first Christine believes him to be the rescuer of her brother, but is then informed by Bombardon of Gontran’s fate. The confusion of her feelings reaches its climax when, a short time later, Gontran returns as an invalid. Above all, Christine feels bound to her vows, but duty and liking are eventually united.