A father and his son Aleksei live together in a roof-top apartment in an unidentified seaside city. The Father is a veteran and Aleksei attends military school to study medicine. They have lived alone for years in their own private world. Sometimes they seem like brothers. Sometimes even like lovers. Despite knowing that all sons must one day live their own lives, Aleksei is conflicted. The father knows he should accept a better job in another city, perhaps search for a new wife.

The film begins by showing The Father comforting his son Aleksei, who just has a nightmare. Following in his father's path, Aleksei attends military school. He likes sports, tends to be irresponsible and has problems with his girlfriend, who is jealous of Aleksei's close relationship with his father. Eventually she breaks up with him. During the weekend, Fyodor comes visiting the Father, who served with his own father in the army, to investigate the mysterious disappearance of the latter. Fyodor revealed to Aleksei that he also visited the previous night, but The Father did not tell Aleksei about it. Aleksei showed Fyodor around the city and went for a tram ride, and Fyodor decides to go to the train station alone and parts with Aleksei. Afterward, Aleksei goes visiting his ex-girlfriend at her place, telling her that he had a dream about them having a baby together. The film ends with The Father being alone on the rooftop covered with snow.