1772. A simple letter shakes the foundations of the Vatican. Which conspiracy could involve the most influential nobleman of Naples? A friend of Charles III, a mason and traitor to his own, an alchemist obsessed with immortality, inventor of the most crazed mechanical apparatuses… Raimondo Di Sangro, Prince of Sansevero, is a dangerous enemy of the Church. Paul Konrad Cuttat, the best man in the service of His Holiness, is sent to Naples on a mission: to investigate the strange schemes of this highly sinister aristocrat. What goes on behind the walls of the Sansevero Palace, in the very centre of the exciting, chaotic city of Vesubio? What revelations does its ostentatious chapel hide? Paul Cuttat will attempt to find out. But the terrifying events he witnesses will make him doubt his convictions and confront his own demons.