It is August 18, 1634. Father Urbain Grandier, convicted of sorcery that led to the demonic possession of the Ursuline nuns of provincial Loudun in France, confesses his sins on the porch of the church of Saint-Pierre, then perishes in flames lit by his own exorcists. A dramatic tale that has inspired many artistic retellings, including a novel by Aldous Huxley and an incendiary film by Ken Russell, the story of the possession at Loudun here receives...