In the grip of a Siberian winter in 1902, a serial killer in Vienna embarks upon a bizarre campaign of murder. Vicious mutilation, a penchant for arcane symbols, and a seemingly random choice of victim are his most distinctive peculiarities. Detective Inspector Oskar Rheinhardt summons a young disciple of Freud - his friend Dr. Max Liebermann — to assist him with the case. The investigation draws them into the sphere of Vienna’s secret societies — a murky underworld of German literary scholars, race theorists, and scientists inspired by the new evolutionary theories coming out of England. At first, the killer’s mind seems impenetrable — his behaviour and cryptic clues impervious to psychoanalytic interpretation; however, gradually, it becomes apparent that an extraordinary and shocking rationale underlies his actions.