On Guard

Lagardère challenges Duke Philippe de Nevers to a friendly duel in Nevers, France. Nevers defeats the challenger but is impressed by the youth and they quickly become friends. During the duel, Lagardère learns the Nevers Attack, a secret lethal maneuver Nevers uses, which the pair will train with and rely on in future peril.

That night, Nevers learns that Blanche de Caylus bore him a child, a fact long concealed by his cousin Gonzague. The revelation hints at a hidden heir who could alter the balance of power in Nevers' world. The secret creates tension as Gonzague's motive to control the birthline becomes clear.

Gonzague's men stage an assassination attempt against Nevers, forcing him to fight for his life. Nevers barely escapes the ambush, prompting him to flee or proceed with caution. The threat from Gonzague is far from over.

Leaving Nevers' side, Lagardère accompanies him toward Caylus as escort. Along the road, Nevers formally teaches Lagardère the Nevers Attack, the acrobatic trick that ends with a blade delivered to the opponent's eyes. The training cements their bond and sets up future collaboration.

The travelers reach Caylus and Nevers marries Blanche, uniting the two families in a rare moment of happiness. The newlyweds' joy is short-lived, as danger continues to loom over Nevers' claim and Blanche's child.

Gonzague's men strike Caylus and murder the entire wedding party. In the ensuing duel, Nevers is fatally stabbed by a masked Gonzague, while Lagardère brands Gonzague's hand with a sword thrust. Nevers dies, naming Lagardère to avenge him and protect their infant.

With Nevers dead, Lagardère flees Caylus with the infant and seeks refuge in the mountains, hiding in an abandoned farmhouse. There, he discovers the baby is a girl, whom he names Aurore, concealing her true lineage from Gonzague's men.

Lagardère and Aurore eventually join a troupe of strolling players, traveling the roads to survive and keep their past hidden. They endure years of wandering as Aurore trains in fencing and the legend of the Nevers Attack begins to influence her own skills.

Sixteen years later, Aurore has grown into a capable young woman. She defends herself against an assault at a party hosted by the host Louis-Joseph, using the Nevers Attack to kill her attacker and escape.

Gonzague learns that Aurore might still be alive and opens her tomb, only to find a decayed wax doll instead of a person. He orders his men to locate and kill her.

Lagardère reveals to Aurore that she is the daughter of Duke Nevers and that Blanche is alive. He gains Blanche's help and, disguising himself as Gonzague's secretary in a hunchbacked disguise, engineers a stock market raid on the Mississippi Company to benefit Aurore.

Aurore is captured but Lagardère rescues her; The Regent Philippe d'Orléans interrupts to appoint Gonzague as royal agent to Louisiana. Lagardère exposes Gonzague's crimes and defeats him in a final duel using the Nevers Attack. Aurore instructs Lagardère to kiss her, and they embrace as the story closes.