Critique of criminal reason

It's 1804, and Prussian magistrate Hanno Stiffeniis has been called to investigate a spate of murders which had reduced Konigsberg to a state of terror. Four people have died, and there is now sign of an end to the killing spree. When the killer tries to murder him, Stiffeniis finds himself confronted by the demons of his own past. Therein lies the sinister source of those murders, and the true reason he has been enticed back to Konigsberg.