Actress Brio working in a cafe "The Happy Canary", does not suspect that her new acquaintances Brianski and Lugovec are Communists sent by an underground committee to fight the enemy's counter-intelligence.
| Actor | Role |
|---|---|
 Galina KravchenkoMademoiselle Brio, variety show artist | Mademoiselle Brio, variety show artist |
 Andrey FaytLugovets | Lugovets |
 Ada VojtsikLugovets's wife | Lugovets's wife |
| SSergei KomarovBryanskiy, underground Bolshevik | Bryanskiy, underground Bolshevik |
 Yury VasilchikovAdjutant for the chief of secret intelligence | Adjutant for the chief of secret intelligence |
 Mikhail DoroninChief of secret counterintelligence | Chief of secret counterintelligence |
| VVladimir KochetovFrench Bolshevik soldier | French Bolshevik soldier |
 Vsevolod PudovkinIllusionist | Illusionist |
 Aleksandr ChistyakovWorker | Worker |
| AAleksandr ZhutaevNot listed | Not listed |
| NN. KopysovNot listed | Not listed |
| VValentina LopatinaNot listed | Not listed |
 Vladimir Tsoppi(uncredited) | (uncredited) |