The Latin inscription "Peccavi"--"I have sinned"--is found scrawled in blood at the scene of a brutal murder. Boston medical examiner Maura Isles and Detective Jane Rizzoli swiftly link the victim to celebrity psychiatrist Joyce O'Donnell, Jane's professional nemesis and a member of the sinister Mephisto Club. Is the killer one of the club's own, or have they inadvertently summoned an evil entity from the darkness?
