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.
| Actor | Role |
|---|---|
| JJules BerryBarnett, alias Arsène Lupin | Barnett, alias Arsène Lupin |
 Gabriel SignoretL'inspecteur Béchoux | L'inspecteur Béchoux |
 Suzy PrimOlga Vauban | Olga Vauban |
 Rosine DeréanGermaine Laurent | Germaine Laurent |
 Aimé Simon-GirardLe journaliste | Le journaliste |
 Thomy BourdelleCassire | Cassire |
 Mady BerryVictoire | Victoire |
| AAbel JacquinBrémond | Brémond |