For generations, the lineage of Margarette Lavalette has passed down from mother to daughter an ancient book of wisdom, a foul book of spells and rituals originating in Africa, old world secrets no one should possess. When Margarette Lavalette dies violently, the book vanishes. Those who know of its forbidden contents think it was destroyed by the mob in an inferno destroying much of the French Quarter. At Our Lady of Sorrows convent, Sister Mary Agnes is found mutilated, the first victim of a serial killer targeting elderly nuns. When Police Detective Sullivan "Sully" Dubois is assigned to the convent to solve the murders, he encounters Sister Rose, his love from high school. Their abrupt separation after a night together has haunted Sully's dreams since, becoming the biggest regret of his life-and unknown to Sully, leaving Rose with a child. And now Rose is suddenly confronted with a decision that no nun should have to make. Celia Battsant, a New Orleans socialite, shares a dark secret with the convent-a link known only to herself and to her secret friend, Picard, the Quasimodo janitor at the convent. She has kept her life in the swamp hidden from her society friends and her husband, Jack, a world-class plastic surgeon. With Picard's help, Celia struggles to fulfill what she believes to be her destiny. One after another, nuns are discovered brutally murdered at Our Lady of Sorrows-tortured, the victims of a killer who apparently will stop at nothing. In the midst of a power struggle at the convent as well as in the archdiocese, both the archdiocese and the archbishop find themselves inextricably caught-up in the murders. A representative from Rome is dispatched... ...a cardinal trained as an exorcist, to close the convent down before the convent's secret is exposed.