Beneath Saint Peter's Bones is the fifth book in The Relic Chronicles. The story begins with Sofia Rossi, an archivist at the Vatican Archives, who discovers a cryptic letter from Pope Clement XIII. The letter hints at a monumental secret buried beneath St. Peter's Basilica, suggesting that the bones beneath the altar are not what they seem.
As Sofia delves deeper into the mystery, she encounters Father Lucio Caravaggio, a rising figure within the Vatican who seems to know more than he lets on. Despite his veiled threats, Sofia's determination to uncover the truth only grows stronger.
Her investigation leads her to the Vatican Scavi, the underground necropolis beneath the basilica. There, she finds herself followed and threatened, but she remains undeterred. With the help of Sister Clara, her confidante, Sofia learns about the Order of the Keys, a secret group within the Church dedicated to guarding this ancient secret.
Sofia's journey is fraught with danger as she navigates the labyrinthine corridors of the Vatican and the hidden passageways beneath the basilica. The stakes are high, and the truth she seeks has the potential to shake the very foundations of the Church.