Studying the circumstances of cases of murders of prostitutes, Nikolai Troitsky guesses that all these crimes are the work of the same person. But for the district police Department, the main thing is to quickly close the case, so a conscientious cop has to conduct his own investigation. Troitsky and the journalist Zhanna, who is interested in this case, notice a strange similarity in the details of the current murders with the London events of 120 years ago.