On September 29, the world awakens to news of the shocking, sudden death of Pope John Paul I, elected only thirty-three days earlier. The Vatican's official response: His Holiness died of unknown causes, "possibly associated with a heart attack." The pope's body is embalmed within twenty-four hours, preventing any possibility of an autopsy. 2006, London: Journalist Sarah Monteiro returns from vacation to find a mysterious envelope stuffed in her mailbox....