The film adaptation of the detective novel of the same name by Anna and Sergey Litvinov. The fourth film in the series "The Adventures of Mitrofanova and Poluyanov". Brilliant journalist Dmitry Poluyanov knew perfectly well that his fiancee Nadia Mitrofanova was an unpredictable girl. But he could not even imagine what secrets of the past would be revealed to him on the eve of the wedding. One after another, murders occur and it is completely unclear who will be the next victim.