n the Vatican, a forgotten debt could save the world-or destroy the Church. Harvard professor Cal Donovan has what every scholar dreams of: unrestricted access to the Vatican Secret Archives.  When he stumbles on evidence of a secret 1848 loan from a Jewish banking family to the Holy See-never repaid and now worth twenty‑five billion euros-his quiet research ignites a deadly Vatican conspiracy. Pope Celestine VI, a reform‑minded pontiff, believes the Church has a moral duty to honor the debt. His radical plan is to use the money to fund a new interfaith humanitarian foundation for the poorest of the poor. But powerful cardinals, corrupt officials, and hired killers will do anything to stop him rather than see the Vatican's wealth, art, and influence sacrificed. From the revolutionary streets of nineteenth‑century Rome to the inner chambers of the modern Vatican and the private vaults of a Jewish banking dynasty, Cal races to uncover the truth about the Church's hidden obligations before the plotters silence him-and the pope-forever. The Debt is a fast‑paced Vatican conspiracy thriller, blending modern Church politics, religious suspense, a historical mystery rooted in the 1848 revolutions, and high‑stakes financial intrigue.  Perfect for readers of religious thrillers, historical mysteries, and political suspense.