During the election of a new Pope in the mid-18th century, famed violinist Antonio Vivaldi learns of a ring of art forgers who are replacing the Vatican’s priceless treasures with expertly-painted fakes. Desperate, the composer hides a message in a special melody, hoping someone, someday, will take down the culprits....

When ex-MI5 operative Joe Mason is sent to Rome to guard an elderly professor and his daughter, he thinks he’s in for an easy ride. But on their first day in the Vatican secret archives, a masked assassin gains entry, shoots Joe’s client in cold blood and steals an ancient manuscript. Giving chase, Joe can’t imagine what could lie within those pages that would make someone willing to kill. The search for answers leads Joe and his comrades in a race against time, across continents and into treacherous mountains.

When Vatican archaeologist Marcus Russo uncovers the fabled Nazi Gold Train buried deep within the Owl Mountains of Poland, he expects to find a forgotten trove of looted treasures. Instead, he unearths a chilling codex that points to a dark and dangerous legacy: Operation Eisenkreuz, a Nazi plan to seed chaos and power across the globe long after their fall. But Marcus soon realizes the train’s secrets are only the beginning.

Amid the grandeur of the Vatican, the bones of Saint Peter—the Church’s most sacred relics—hold secrets that could reshape its history. Father Michael Dominic, Prefect of the Vatican Secret Archives, uncovers a mysterious, nearly forgotten inscription linking Linus, Saint Peter’s first successor, to foundational decisions that shaped the early Church. What begins as a scholarly exploration of Linus’s legacy quickly turns into an urgent quest to protect the truth.

Former FBI profiler Adrian West is in Rome for a history conference when she learns that her friend and colleague, Dr. Sebastian Rossi, has been abducted.