In the winter of 1937, Eugenia Semyonovna Ginzburg is a loyal and active Communist Party member, schoolteacher, and writer. She is a good mother and a loyal wife to Pavel, who is also a loyal Communist and Party worker. When a Communist Party official is assassinated, Stalin's regime seeks out the culprits, arresting anyone for the slightest offenses. Ginzburg's friend Elvov, a writer who has contributed an article to a history of the Communist Party, is targeted because Stalin says the article is full of Trotskyist ideas. Elvov is arrested, and Ginzburg is arrested for not denouncing Elvov. Ginzburg is taken to Black Lake, a lakeside resort town which also has a secret police building. There she is interrogated and accused of terrorism and her case is referred to military tribunal in Moscow.

The military tribunal finds her guilty and sentences her to ten years of imprisonment and five years without civil rights. For the next three years, Ginzburg suffers horribly as she is shifted between prisons, brutally interrogated, denied adequate food, water, and medical care. Her sentence is revised and she is ordered to carry out the rest of her sentence doing hard labor in an isolated prison camp called Kolyma, and then to the state farm Elgen. There, she is forced to fell trees in the freezing snow without proper clothing or protection against the elements. By bribing her prison team leader, Ginzburg is given work in the guesthouse and the kitchens.

She later meets a visiting doctor named Petukhov. Petukhov recognizes Ginzburg from her family resemblance to her son who is staying in Leningrad with family, and Petukhov arranges to have her work in the children's hospital at the camp because Ginzburg can read Latin. In the epilogue, Ginzburg states that she had originally intended to write the book as a letter to her grandson.