The life of Pavla Brus, a middle-aged, modest but principled woman, suddenly changes with a crush on a drilling foreman. Unable to restrain her feelings, she decides to cheat on her husband, divorce and leave the family. But her youngest son Kuzma, a teenager with an intelligent and piercing look at the world around him, stops her from a rash act, which is shaped by observation of Siberian nature. A philosophical attitude towards banal life processes allows the mother to reconsider her feelings for her husband Tikhon and the failed lover Nikolai.

Дошкольник Кузьма из глухого сибирского села, сообразно окружающей природе, чист, непоколебим и восприимчив как к добру, так и ко злу. Малыш все видит и примечает — и в конце концов дает хороший урок нравственности непутевым родителям.