Criminal investigation is investigating the case of robbery of the factory cashier. At the checkpoint of the factory of precision mechanics and optics, two criminals attack the cashier. Criminals manage to escape by the car, waiting for them around the corner. At the scene of the crime, criminal investigation officers arrive Major Dorokhov and Lieutenant Matushkin. They interview witnesses, but they did not remember properly any attackers or machine numbers, but noticed that one prevented the other from firing.

After returning from the army, Sasha learns that Tonya, whom he loves, met another guy, became a mother, is raising a child and works in an oil field in the Gomel region. Sasha goes to the oil field to see Tonya for a possible explanation.