In the late 1600s, King Louis XIV assigns Nicolas de la Reynie to bring order to the city of Paris after the brutal deaths of two magistrates. Reynie, pragmatic yet fearless, tackles the dirty and terrifying streets only to discover a tightly knit network of witches, poisoners, and priests whose reach extends all the way to Versailles. As the chief investigates a growing number of deaths at court, he learns that no one is safe from their deadly love potions and 'inheritance stews', not even the Sun King himself.

Nicolas de La Reynie, appointed by Louis XIV as the first police chief of Paris, pursues criminals through the labyrinthine neighborhoods of the city, unearths a tightly knit cabal of poisoners, witches, and renegade priests, and discovers that the distance between the quiet backstabbing world of the king's court and the criminal underground is disturbingly short. As he continues his investigations, La Reynie suspects that Louis's mistresses are involved in many of the nefarious plots he has uncovered, and he must decide just how far he will go to protect his king. Tucker has crafted a gripping true-crime tale of deception and murder based on thousands of pages of court transcripts and La Reynie's notebooks, letters, and diaries.