USSR, 30s After the death of her husband, Sofya Petrovna enters typewriting courses in order to get a specialty and to be able to support herself and her son Kolya. Being competent and accurate and having received the highest qualification, she easily gets a job at a large Leningrad publishing house and soon becomes the head of the typewriting bureau. Despite the early rising, unfriendly faces in the transport, the headache from the knocking of cars and the tiresomeness of production meetings, Sofya Petrovna really likes the work and seems exciting. In young typists, she values literacy and diligence above all; those respect her and are slightly afraid, calling her a cool lady behind her eyes. The director of the publishing house is a pleasant, well-mannered young man. Of all the girls in the bureau, Sofya Petrovna is most attractive Natasha Frolenko, “a modest, ugly girl with a greenish-gray face”: she always writes elegantly and without a single mistake.
Meanwhile, the son of Sofya Petrovna, Kolya, grew up completely, became a real handsome man, graduated from high school and soon, together with his closest friend Alik Finkelshtein, entered the Engineering Institute. Sofya Petrovna is proud of her smart, beautiful and neat son and worries that the adult Kolya does not have a separate room: they were sealed at the very beginning of the revolution, and now the former apartment of the family of Sofya Petrovna has become communal. Although Sofya Petrovna regrets this, she accepts the explanations of her advanced son about the "revolutionary sense of consolidating bourgeois apartments." Sofya Petrovna was beginning to think about exchanging one room for two at a surcharge, but at that moment “the honors students, Nikolai Lipatov and Alexander Finkelshtein, were sent to Sverdlovsk, Uralmash, by masters for some kind of development,” while making it possible to graduate from the institute in absentia. Sofya Petrovna yearns for her son, begins to work much more, and in her free evenings she invites her work friend Natasha Frolenko to tea. Once she gives Natasha, at her request, Colin the last photograph (later Sofya Petrovna realizes that Natasha is in love with Kolya). Often they go to the movies "for films about pilots and border guards." But Natasha shares her problems with Sofia Petrovna: she is not accepted into the Komsomol in any way, since she is from a "bourgeois-landowner family." Sofya Petrovna is very sympathetic to Natasha: such a sincere, warm-hearted girl; but the son in the letter explains to her that vigilance is necessary.
Years go by, Sofya Petrovna is promoted, and meanwhile the holiday is approaching: a new one is coming, 1937. The organization of the holiday was entrusted to Sofya Petrovna; she succeeds well, but the general triumph is overshadowed by strange news: many doctors were arrested in the city, and among them - Dr. Kiparisov, a colleague of the late husband Sofia Petrovna. From the newspapers it follows that doctors are associated with terrorists and fascist spies. It’s hard to believe about Kiparisov: it’s a decent person, a “respectable old man”, but they won’t put us in vain! And if Kiparisov is not to blame, then he will soon be released and an unpleasant misunderstanding will be dispelled. After some time, an even stranger event occurs: the director of the publishing house is arrested. And just at the moment when Sofya Petrovna and Natasha were discussing the reasons for the arrest of the wonderful director, a “seasoned party member,” in whom the publishing house “always carried out an excess plan,” a doorbell suddenly rings: Alik arrives with terrible news about Kolya’s arrest.
Sophia Petrovna’s first impulse was “to run away now and clarify this monstrous misunderstanding.” Alik advises going to the prosecutor’s office, but Sofya Petrovna doesn’t really know where the prosecutor’s office is, or what it is and goes to jail, because she accidentally knows where she is. On the street, not far from the prison, she suddenly finds a large crowd of women with tired greenish faces, dressed out of season warmly: in a coat, felt boots, hats. It turns out that this is the turn to the prison, consisting of relatives of the arrested. It turns out that in order to try to learn at least something about his son, you need to sign up and defend a huge queue. But Sofya Petrovna manages to find out only that Kolya is in prison and that the transfer for him will not be taken: "he is not allowed." She knows neither what her son was arrested for, nor whether the trial will take place, nor whether “when this stupid misunderstanding will finally end and he will return home”: certificates are not given anywhere. Every day, she continues to naively expect that, having opened the door to the house, she will see her son there, but the house remains empty.
Meanwhile, the secretary of the previously arrested director is being dismissed as a person associated with him, and Natasha Frolenko - for a typo, interpreted as a malicious anti-Soviet attack: instead of "Red Army" she accidentally printed "Rat Army". Sofya Petrovna decides to intercede for Natasha at the meeting, but this does not lead to anything other than an anonymous charge of her partnership with Natasha, and Sofya Petrovna is forced to resign. And along the way, it turns out that Kolya was sentenced to ten years in the camps and that he himself admitted to terrorist activities. Unlike Sophia Petrovna, who is sure that the young Kolya was simply confused, Natasha begins to wonder: why did most of those arrested admit their crimes, because they could not confuse everyone ?!
Meanwhile, Alik was expelled from the Komsomol, and soon arrested: one of the Komsomol members reports that Alik was friendly with Kolya, and Alik refuses to "dissociate" from his comrade. Natasha commits suicide by writing in her dying letter to Sofya Petrovna “I cannot figure out the present moment of Soviet power.”
Months pass, the very aged Sofya Petrovna accumulates canned food in case she needs to be sent to her son. With sorrow, she invents and repeats to others that Kolya was released, and she believes in it, when suddenly a letter comes from Kolya. He writes that he was arrested on the false denunciation of a classmate and that the investigator kicked him. Kolya very much asks the mother to do something, but Kiparisova, the wife of the repressed doctor, dissuades her: then they can send her as well, as they send Kiparisova herself after her husband, but this will not help her son, she will only do harm. Sofya Petrovna thinks for a long time where to go with this letter, but, realizing that there is nowhere to go, and completely desperate, she decided to burn the letter - a dangerous evidence, "threw fire on the floor and trampled with her foot."
