Having lost his memory due to serving in World War I, Gaston has spent the past 15 years in a psychiatric hospital. Due to his large disability pension fund, several families claim him as their missing son. Gaston is introduced to the Renaud family by the Duchess Dupont-Dufort and her lawyer. The Renaud family attempt to revive Gaston's memory with stories of his past, but he is apalled by some of the things he hears and dislikes the man he is supposed to be.
| Actor | Role |
|---|---|
 Pierre FresnayGaston | Gaston |
 Pierre RenoirGeorges Renaud | Georges Renaud |
 Blanchette BrunoyValentine Renaud | Valentine Renaud |
 SylvieMadame Renaud | Madame Renaud |
| MMarguerite DevalDuchess Dupont-Dufort | Duchess Dupont-Dufort |
 Jean BrochardMarcel Berthier | Marcel Berthier |
 René GéninVicar | Vicar |
 Louis SalouMaître Uspard | Maître Uspard |
 Odette BarenceyParent | Parent |
 Mercédès BrareNot listed | Not listed |
| PPierre BruléLittle boy | Little boy |
 Jenny BurnayJuliette | Juliette |
 Marie-Jacqueline ChantalNot listed | Not listed |
 Léonce CorneManservant | Manservant |
 Etienne DecrouxNot listed | Not listed |
 Gabrielle Fontan'La mère Lampion' | 'La mère Lampion' |
| HHenri GaultierMaître d'hôtel | Maître d'hôtel |
 Léon LariveChauffeur | Chauffeur |
 Albert MalbertLacassagne | Lacassagne |
 Marthe MellotMadame Berthier | Madame Berthier |
 Julienne ParoliOld girl | Old girl |
 Odette TalazacCook | Cook |
| MMarcel TalmontNot listed | Not listed |
 Eugène YvernèsNot listed | Not listed |