Armen is an employee of the State Archive, an irrepressible young man, who is not indifferent to the grief, injustice, and meanness of other's. Armen feels responsible for solving these problems, even though they have no direct bearing on him.

Two years after receiving news of his father’s death in WWII a young boy continues to wait for trains from the front. The boy lives with his crippled uncle rather than with his mother, who has remarried and has another child. Then one day the father returns.

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.