The famous ballet dancer Igor Bayramov, the husband of private detective Margarita Sinyavskaya, is invited to participate in the production of the opera “The Ring of the Nibelung”. The main part will be sung by Igor’s childhood friend, the world-famous blind singer Alina Kayurova. And soon Alina’s secretary turns to Margot with a request to find the man who has been writing letters to Alina for many years, judging by which he closely follows her and her life. According to the secretary, recently these letters have become downright frightening.