Film "Stranger in the House"
Genre: Detective Melodrama

Unable to bear the hazing, a young soldier grabs a machine gun, fires a short burst at his attacker, and flees. Nearby is a dacha community where he used to live, and he heads there to change clothes and get some money. A normal family lives in the house: a father, a mother, a 12-year-old girl, Nastya, and a two-year-old boy, Vanya. During the day, the parents and the baby go to town, leaving Nastya alone to care for the house. Since Vanya was born with a health condition (diabetes), all of her parents' attention is focused on him, and the girl feels abandoned and is intensely jealous of the baby.
And so, after seeing her parents off to town, Nastya discovers a stranger in the house. When the initial panic from the cat-and-mouse game subsides, 18-year-old Sasha introduces himself as her half-brother. Apparently, in his distant childhood, his father abandoned him and his mother; they moved to another city, and his father remarried. Whether this is true or not remains unclear until the very end of the film, as the girl alternately finds both facts confirming and refuting this information. Sasha needs a serious talk with his father, but until then, the boy needs to hide—the police are already prowling the village. Nastya is a little afraid of the stranger, but curiosity gets the better of her, and she decides to help.
That evening, his father arrives in a bad mood, and the introduction has to be postponed until the next day, leaving Sasha to spend the night in the bathhouse. Nastya tries to get her father to talk about his previous marriage, but he becomes enraged and denies everything. The boy's introduction to his father goes no better—except for shouting and cursing, the first meeting ends in nothing. Nastya even gets slapped for her part in this outrage. The offended girl devises a plan to punish her hard-hearted father, who doesn't care about his adult children. She suggests that Sasha kidnap Vanya and demand a ransom. The money he receives will be enough for Sasha to escape. Nastya deliberately conceals information about Vanya's diabetes, hoping that her parents' attitude toward her will change if she remains an only child.
Everything goes according to plan. Sasha steals a car with Vanya lying inside and, using the cell phone he took from Nastya, demands the ransom from his father. While his father searches for the necessary sum, Vanya falls into a coma—he needs an insulin injection. Torn between self-preservation and mercy, Sasha finally decides to take the child to the hospital. Meanwhile, Nastya, nearly driven mad by her own cruelty, confesses everything to her parents. Vanya is saved. Sasha manages to escape and finds work on a construction site. The soldier he wounded at the beginning of the film survives.