Plot synopsis: Homicide investigator Efremov makes an unforgivable mistake, as a result of which his colleague, friend and mentor dies. The hero himself loses his sight, but seeks to return to service. Blindness sharpens the rest of his senses to the limit, which allows him to "see" what others miss. Now Efremov masterfully investigates complicated crimes, but the past haunts him. Will the unique investigator be able to solve that fatal crime and somehow correct the mistake he made?