In the winter of 1679, a woman walked out of a church in Paris and into the hands of the police. Her name was Catherine Monvoisin, but all of Paris knew her as La Voisin: "The Neighbor." She read palms, sold love potions, and, investigators claimed, supplied poison to some of the most powerful women in France. Behind her garden wall, they said, a priest said midnight masses over a naked woman's body, and the blood of infants was offered to demons for the love of a king.

This Halloween, we go to the edge of seventeenth-century Paris, to a house with a furnace in the garden, a courtroom draped in black, and a scandal so dangerous that Louis XIV ordered the evidence sealed. What did La Voisin really do? What was invented under torture? And who, exactly, was she selling to?

Content note: this episode discusses poisoning, infant death (alleged), torture, and execution by burning. It is based on historical sources, and much of the most sensational testimony was extracted under duress. We'll flag what is documented and what is legend.

SOURCES AND FURTHER READING
Books and scholarship

• Anne Somerset, The Affair of the Poisons: Murder, Infanticide, and Satanism at the Court of Louis XIV (New York: St. Martin's Press, 2003). The best modern English-language narrative and a core source for this episode.
• Lynn Wood Mollenauer, Strange Revelations: Magic, Poison, and Sacrilege in Louis XIV's France (University Park: Penn State University Press, 2007). A careful study of the trials and the culture of magic and sacrilege.
• Frances Mossiker, The Affair of the Poisons: Louis XIV, Madame de Montespan, and One of History's Great Unsolved Mysteries (New York: Knopf, 1969). An older, popular narrative.
• Frantz Funck-Brentano, Le Drame des poisons (Paris, 1899). Foundational early scholarship, available in English as Princes and Poisoners (1901).
• François Ravaisson (ed.), Archives de la Bastille (Paris, published in volumes from the 1860s onward). Published documents from the Bastille archives, including material from the Chambre Ardente.
• Nancy Mitford, The Sun King (1966). For general background on Louis XIV's court, including Madame de Montespan.

• Madame de Sévigné, Letters (to her daughter, Madame de Grignan). The letter following La Voisin's execution (dated the 23rd of February 1680) is the best-known contemporary account of her final days. Many English translations exist. Her letters also track the Brinvilliers scandal.

• Encyclopædia Britannica (1911 ed.) entry "La Voisin," notes the role of La Reynie's preserved notes and gives the fate of other prisoners.
• Wikipedia, "La Voisin," and "Affair of the Poisons" (useful for dates and names; note that the "2,500 victims" figure appearing there and elsewhere is unsourced and should be treated with caution).
• Encyclopedia.com, "La Voisin (?-1680)."
• Paris Zigzag, "Paris sombre : la terrifiante Affaire des Poisons" (French-language popular history; useful on Desgrez and the Chambre Ardente).
• Connexion France, "Sorceress, midwife, poisoner: meet La Voisin."