Plot synopsis: St. Petersburg, 1912. The progress of the new century is coming, but human nature does not change with progress - people still take each other's lives, sometimes in the most terrible and incredible ways. Every time the metropolitan police, together with all its modern equipment (and there is already fingerprinting, and much more), cannot cope with another terrible murder, the luminary of surgery, a 40-year-old professor of medicine Voskresensky, is called to help. The cases that Voskresensky has been investigating for eight episodes are the most inexplicable and terrible. But series after series, case after case, Voskresensky proves that there are quite real murderers behind unexplained crimes who cannot restrain the dark sides of their desires - and this, alas, is quite in human nature.