Quick recap
Twenty-year-old Raoul d'Andrésy isn't the famous Arsène Lupin yet. In love with Clarisse, Baron d'Étigues's daughter, he learns that the baron and a group of nobles led by Beaumagnan plan to kill Joséphine Balsamo, who claims to be Cagliostro's daughter and never to age. Raoul saves her and falls for her. Together, and then against each other, they race the nobles for the secrets of a hidden treasure. Joséphine teaches Raoul the art of crime but also shows a cruel side he can't accept. The contest ends with Raoul winning and walking away from her, a young thief ready to become Lupin.