The wealthy industrialist Alain de Narbois has disappeared. Michel Dunant, an idle man who passed by and who looks exactly like the deceased, is taken for Alain by a young woman and her servant. He jumps at the chance but quickly realizes that, in this hushed little world, masters and servants play comedy and know very well that he is only a double of Alain. In fact, the industrialist was assassinated.
| Actor | Role |
|---|---|
 Simone RenantMarianne Séverin | Marianne Séverin |
 Michel AuclairMichel Dunan, Alain's look-alike / Alain de Norbois, missing man | Michel Dunan, Alain's look-alike / Alain de Norbois, missing man |
 Marcel HerrandNorbert, butler | Norbert, butler |
 René BlancardMe Tirgen, lawyer | Me Tirgen, lawyer |
 André VersiniAdrien | Adrien |
 Guy FavièresGuillaume | Guillaume |
 René HellPlayer | Player |
| RRoger BontempsInspector | Inspector |
| PPaul DelonInspector General Leroux | Inspector General Leroux |
 Teddy BilisNot listed | Not listed |
| NNicole GammaNot listed | Not listed |
| JJean-Jacques DuvergerPaul de Norbois | Paul de Norbois |
 Robert VattierAdolphe Mercier, businessman | Adolphe Mercier, businessman |
 Jacques CastelotInvestigating judge | Investigating judge |
 Geneviève PageCarole de Norbois | Carole de Norbois |
| RReine CharmyNot listed | Not listed |
 Marcelle Arnold(uncredited) | (uncredited) |
| JJean Brunel(uncredited) | (uncredited) |
 Paule Launay(uncredited) | (uncredited) |
 Marcel Rouzé(uncredited) | (uncredited) |
| RRené Sauvaire(uncredited) | (uncredited) |