Arsène Lupin decides to run a detective agency in addition to being a gentleman thief. As a detective he happens to cooperate with police in order to unveil the criminal activities of a villain. When he succeeds the villain returns the favour. The unmasked Arsène Lupin manages to escape with the villain's gangster moll as his new companion.

• Le Film d'art
• Jules Berry
• Gabriel Signoret
• Suzy Prim
• Rosine Deréan
• Aimé Simon-Girard
• Thomy Bourdelle
• Mady Berry
• Abel Jacquin