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

The film shows the struggle of the Chuvash people for their rights at the beginning of the 20th century.