Professor Artus, a scientist specializing in artificial life, wants to try an experiment on an automaton; he is entrusted with a death row inmate. The professor is soon found murdered. It is Inspector Wens, helped by a journalist, who must solve the case. Franck Villard in the role of Wens succeeds Fresnay.
| Actor | Role |
|---|---|
 Louise CarlettiArlette | Arlette |
 Frank VillardInspector Wens | Inspector Wens |
 Roger KarlProfessor Artus | Professor Artus |
 Jean TissierTiburce Artus | Tiburce Artus |
| JJean TémersonHector, butler | Hector, butler |
 André FouchéMaxime Artus | Maxime Artus |
 Jim GéraldRamshow | Ramshow |
 Eugène YvernèsChauffeur | Chauffeur |
| JJean BertonCommissioner | Commissioner |
 Maurice LagrenéeNot listed | Not listed |
 Michel MarsayNot listed | Not listed |
| DDenyse RéalNurse | Nurse |
| HHuguette MontréalAndrée | Andrée |
| PPaul DelauzacDoctor | Doctor |
| JJean Gabert(uncredited) | (uncredited) |
| RRolande Haumont(uncredited) | (uncredited) |
 Julien Maffre(uncredited) | (uncredited) |
 Henri Marchand(uncredited) | (uncredited) |
 Colette Ripert(uncredited) | (uncredited) |