Three children are massacred in their beds. The crushed corpse of their mother is discovered in a dockside warehouse. Then the husband, Bruno Gottewald, is dead and buried — killed while out on field manoeuvres. In less than a week, the entire Gottewald family has been wiped off the face of the earth. A tragic coincidence? Or are the invading French army using the massacre to expand their power? Hanno Stiffeniis, a Prussian magistrate, goes to investigate the deaths, seeking to discover how the crime was committed and the motive behind the massacre. But only Hanno's wife, Helena, knows what truly happened in that cottage in the woods...

It's the year 1793, and Hanno Stiffeniis is a magistrate in Prussia. He has been called to investigate a spate of murders which has reduced the city to a state of terror, under the watchful gaze of his mentor, Kant. Four people have died, and there is no sign of an end to the killing spree. When the killer tries to murder him, the magistrate 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... Hugely atmospheric, entertaining and intelligent, Critique of Criminal Reason is the first in a series of compelling crime novels set in Prussia featuring Hanno Steffeniis.