1918. After the death of the mother, the father decides to take the children to Moscow to see a distant relative. On the way, the guys experience a raid by a White Guard gang on a train, the death of their father, and meet the homeless child Yashka, who brings a plan to Lenin - how to destroy all the bourgeoisie and all the counter-propaganda in one day. The boys become involved in revolutionary events, and ahead is Moscow, a chance meeting and conversation with Lenin and Dzerzhinsky, the fight against counter-revolution...

In Africa, monkeys fell ill. This news was reported to Dr. Aybolit by the monkey Chichi, who escaped from the robber Barmaley. Aybolit and his assistants — Chichi and the dog Avva — are in a hurry to save the monkeys from the disease. But Barmaley and his robbers are trying to stop them.

A group of gangsters are kidnapping two boys: a son of a billionaire and a son of a USSR ambassador.