The Comte de Gonzague plots against his cousin, the Duc de Nevers, despite being the Duke’s heir and set to inherit his properties. The Count has hidden the fact that the Duke has an illegitimate child who was recently born. Upon discovering his child’s existence, the Duke sets out to marry the child’s mother, a baron’s daughter, at her father’s secluded chateau. However, the castle’s residents are taken by surprise and killed by the Count and his men. The only survivors are the Duke’s ally, the expert swordsman Lagardère, and the baby girl, who is now the legitimate heiress to the Duke’s extensive wealth. The Count assumes they have perished in a drowning accident, but in reality, they have been sheltered by a traveling group of Italian performers. Two decades later, the Count learns that they are still alive and attempts to have them killed. However, Lagardère, using a clever disguise as a hunchback, manages to earn the Count’s trust and secures a position as his bookkeeper.