The experienced major Bagryshev jealously perceives the attachment of the young trainee Solomatin to him, thinking that his appearance will only bring retirement closer. However, the first symptoms of Alzheimer's further aggravate his situation — Bagryshev realizes that he will have to resign. Solomatin believes that the major is a real ace in the operational search, and it is from him that he must learn to become a first—class policeman. Therefore, he offers the new boss to conclude a contract: Bagryshev transfers all his experience and knowledge to him, and in return he becomes a kind of "RAM" for him, that is, he helps in every possible way and cleans up all his punctures. Bagryshev agrees. On the first day of working together, the partners discover corpses in the lake. The method of murder resembles the handwriting of a maniac whom Bagryshev shot during arrest several years ago. The major and the trainee will have to get to the truth in this complicated case, but they do not have much time, because important "files" are erased from the head of an experienced investigator.