 It details the attempts of a young Prussian magistrate, named Hanno Stiffeniis, to catch a murderer who has committed a series of grotesque and unsettling murders in the city.He is aided in the task by a sergeant of the local police, Herr Köch, and together they create a pair of heroes slightly reminiscent of the Sherlock Holmes and Dr. Watson tandem.Of note is the historical character of Immanuel Kant, who also takes an important part in the investigation.