A French animal lover protects a dog and a mouse wanted by Soviet scientists for their space program.
| Actor | Role |
|---|---|
 Noël-NoëlLéon Martin | Léon Martin |
 Denise GreyMarguerite Martin | Marguerite Martin |
 Francis BlancheChazot | Chazot |
 Nathalie NervalDina, interpreter | Dina, interpreter |
| CConstantin NepoSoviet ambassador | Soviet ambassador |
 Robert LombardGendarmerie adjutant | Gendarmerie adjutant |
 Pauline CartonMarie | Marie |
 Harry-MaxDoctor | Doctor |
 Serge NadaudSoviet cultural attaché | Soviet cultural attaché |
 Henri CoutetVillager | Villager |
 Sophie DaumierMireille Martin | Mireille Martin |
 Gil VidalPaul de Grandlieu | Paul de Grandlieu |
 Mischa AuerProfessor Papov | Professor Papov |
 Darry CowlHubert, government delegate | Hubert, government delegate |
 Noël RoquevertMayor of Lésigny | Mayor of Lésigny |