A toymaker in Poland specializes in building lifesize mechanical men. He builds a chess-playing "automaton" to hide a pretty young Polish activist who is being hunted by occupying Russian forces.
| Actor | Role |
|---|---|
 Françoise RosayCatherine II | Catherine II |
 Conrad VeidtLe baron de Kempelen | Le baron de Kempelen |
 Bernard LancretLe prince Serge Oblonsky | Le prince Serge Oblonsky |
 Micheline FranceySonia Vorowska | Sonia Vorowska |
 Paul CamboLe prince Boleslas Vorowsky | Le prince Boleslas Vorowsky |
 Jacques GrétillatPotemkine | Potemkine |
| JJean TémersonStanislas | Stanislas |
 Edmonde GuyWanda Zalewska | Wanda Zalewska |
| DDelphinNot listed | Not listed |
 Manuel GaryNot listed | Not listed |
 Gaston ModotNot listed | Not listed |