At the "Pupky" station, an opportunity occurs: two illegal passengers - guinea pigs - have to be disembarked from one of the trains, since animals cannot be transported in a general carriage. The head of the station Pryvychkin tries to help the animals, but the situation is beyond his control. The audit committee sets out to investigate the unpleasant incident... This witty satirical comedy, in which bureaucracy, bourgeoisie and provincialism are mocked, continued the development of the domestic comedy genre in Ukrainian Soviet cinema.

A group of 6th grade school children master their everyday lives. Van'ka has inventive talent, but he can't cope in class. His loyal friend Aleša tries to protect him. The curious and ambitious Katja thinks Van'ka is lazy, but she also has some problems at school due to her great commitment to the pioneer group, of which all three of them are members. Will Van’ka and Katja successfully complete the school year or have to repeat the 6th grade?

The Red Army enters the city, while the White Army leaves it. There are only two people in the landlord’s estate, an old doorkeeper and a grammar school student, the landlord’s son. The house is taken by the Red Army detachment, and the doorkeeper’s son Andrii, a Bolshevik, is among them. The old man does not share his beloved son’s views and protects the landlord’s son hiding him in the attic.

The end of the 1920s. The capitalist world is in crisis. The fascists unleash war against the Soviet Union. The enemy attack interrupts the peaceful labor of Soviet people. Hundreds of production workers join the Red Army. At the front go Red Army units, columns of tanks, units of the people's militia. Enemy airplanes appear over the Soviet city, black bomb bursts are rising. The streets are moving mournful funeral processions of the first victims of the war. At the end of the movie, a worker appears on the screen, appealing to the audience to be ready for the war, which has not yet come, but will come “maybe tomorrow"