Most honourable Procurator Stiffeniis, You talents have been brought to Our attention by a gentleman of eminence, who believes that you alone are capable of resolving a situation which holds Our beloved Königsberg in a grip of terror. All Our faith and consideration are due to the notable personage who suggested your name, and that same faith and consideration now resides in you. We have no reason to doubt that you will accept this Royal Commission, and act accordingly with all haste. The fate of the city lies in your hands. —King Frederick Wilhelm III It has been years since Immanuel Kant's landmark philosophical work, Critique of Pure Reason, brought him fame throughout Europe and made him Königsberg's best-known citizen. Now, rumors have begun to surface of a new work by this aging but still acute mind. Yet unlike his earlier work, this book will not examine the mind of the average man, but the mind of the serial killer. Hanno Stiffeniis, a young magistrate, has been called to Königsberg to assist in the investigation of an enigmatic string of murders. Is it part of a plot formed by Napoleon's spies to undermine the Prussian king or the work of a solitary, unknown killer? The case would seem unsolvable, were it not for the assistance and unmatched intellect of his mentor, Immanuel Kant. Together Stiffeniis and the elderly, eccentric philosopher must track down the killer who has the city of Königsberg by the throat. Hugely atmospheric, entertaining, and intelligent, Critique of Criminal Reason marks the outstanding debut of a new name in historical fiction.

Three children are massacred in their beds. The crushed corpse of their mother is discovered in a dockside warehouse. Hanno Stiffeniis, a Prussian magistrate, goes to investigate, but everything begins to unwind. Serge Lavedrine, a criminologist attached to the invading French army, steps in to resolve the mystery, and Stiffeniis is packed off to collect the husband from a remote fortress on the Russian border. But 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? A military conspiracy involving Prussian troops? Or are the French using the massacre to expand their power?

Prussia has been overrun by Napoleon’s forces, and the Emperor’s troops have discovered a new source of funds enough amber to finance France’s wars. But their plans stall when the girls who collect the stones begin to disappear, only to be found gruesomely disfigured by an unknown killer. The French call upon Prussian investigator Hanno Stiffeniis, who must seek out the culprit knowing hat his own success may doom his country’s future. Dark, intelligent, and vividly written, A Visible Darkness continues a masterful series of historical mysteries that portray a past torn between nationalism and humanism, superstition and science.

A woman's body has been found at the bottom of a well. The death wounds are startling: two small, round punctures to the jugular vein... Vampire fever is spreading throughout the countryside, and suspicions soon fall on the recently arrived Emma Rimmele. Investigator Hanno Stiffeniis must do everything he can to find the true culprit before the mob's hysteria reaches its breaking point and turns violent. Set in a nineteenth-century world where people truly believed in vampires, Unholy Awakening pits rational, scientific detection against unhindered, violent superstition.