Book 1

It's 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. Tension inside the city is heightened by the imminent threat of invasion; Napoleon is menacing the borders of Prussia, so whilst hunting for the murderer, the city of Konisberg is forced to deal with scheming whores, necromancers who claim to speak with the victims, and the scum of the Prussian army. 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.

Book 2

Days of Atonement

by Michael Gregorio

Published 2 August 2007
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 . . .

Book 3

A Visible Darkness

by Michael Gregorio

Published 14 April 2009
Hanno Stiffeniis, the magistrate from the gripping thrillers "Critique of Criminal Reason" and "Days of Atonement", is called to Prussia's Baltic coast, where the naked, mutilated body of a young woman has been found by the shore. This is an area rich in amber, harvested - mainly by women - to be transformed into priceless jewellery. The occupying French army has taken over this lucrative trade to finance the battle against the Russian invasion, but as more women are killed, they suspect the Prussian resistance movement. Hanno's fears meanwhile point towards a psychotic serial killer, and no woman here is safe.

Book 4

Unholy Awakening

by Michael Gregorio

Published 5 August 2010
A female corpse is found in the town of Lotingen. The girl's neck has been ripped open, all the blood drained from the body. Hanno Stiffeniis hastens to investigate a case more terrifying than murder. Would any human being kill in such a gruesome fashion? Emma Rimmele has come to Lotingen to bury her mother. A beautiful woman travelling with a coffin in her baggage, Emma attracts gossip like a magnet. When a corpse is discovered near the house where she is living, speculation about the mysterious stranger reaches fever pitch. When two more ravaged bodies are found, fingers point accusingly in her direction. One word is heard on every tongue. Vampire ...News arrives from a nearby town. A French officer's throat has been ripped out. Another French soldier has bled to death. The horror of Lotingen is happening elsewhere. Colonel Lavedrine, a criminologist in the Grand Armee, is ordered to collaborate with Magistrate Hanno Stiffeniis. Two years earlier, they had worked together to solve a murder despite fierce clashes of character and opinion.
Once again, each man is drawn into the forbidden world of dark graveyard paths and reading in pursuit of a curse which has plagued Prussia for centuries.