A squadron of American warplanes, armed with gas developed by Corsican chemist Gannimer (dubbed "Napoleon Gas") flies to Leningrad. American workers inform soviet comrades about the impending catastrophe. But the air attack on the city has already begun, and the assault troops of the enemy capture one suburb of the city after the other. The Red Army is organizing the defense and reflects the attack of the enemy with gas-armed drones
| Actor | Role |
|---|---|
 Yevgeni BoronikhinNapoleon Ginimer, engineer-chemist | Napoleon Ginimer, engineer-chemist |
| YYelena ChaikaNatalia Ivanovna, instructor | Natalia Ivanovna, instructor |
| RRoman RubinshteynJim Dugan, king of anilin | Jim Dugan, king of anilin |
 Iona TalanovMinister of war | Minister of war |
| PPetr KuznetsovArchbishop | Archbishop |
| OOlga SpirovaIrma Grant, aviator | Irma Grant, aviator |
| NNadezhda FridlyandLetrice Grant | Letrice Grant |
| SSergey GalichHerbert Bell, worker | Herbert Bell, worker |
| VV. LandeEllie Forstet, worker | Ellie Forstet, worker |
 Pyotr PodvalniyChief engineer | Chief engineer |
| PPetr ShidlovskyCommissar of defence of Leningrad | Commissar of defence of Leningrad |
 Yakov GudkinForeign businessman | Foreign businessman |
 Irina VolodkoNot listed | Not listed |
| KKonstantin GibshmanNot listed | Not listed |
| AAleksey GoryushinArmoured car driver (uncredited) | Armoured car driver (uncredited) |
| VVasiliy Chudakov(uncredited) | (uncredited) |