A young man discovers that his father behaved dishonourably during wartime.

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.

苏俄国内战争时期两名共青团员马特维约夫和贝扎伊斯被游击总部派往哈巴罗夫斯克边疆区前线传达信息。在哈巴罗夫斯克，马特维约夫碰到了同为团员的丽莎，并爱上了她。随后的战斗中马特维约夫救了丽莎，但最终他中了白军巡逻队的子弹。最后马特维约夫在丽莎的怀中闭上了双眼，丽莎眼中泛出了晶莹的泪光。