Inspector Andrei Krutitsky is assigned to investigate the mysterious suicide of a young mother. Before slitting her wrists, Olga Maltseva suffocated her own son with a pillow. Olga's lover claims that she was driven to suicide by the ghost of her father, who died 12 years ago in an accident at a chemical plant. The ghost appeared to her every day, persuading her to kill her son. Immediately after the conversation with the investigator, the man also commits suicide.