The Vatican has been trying for years to debunk the idea that its vaunted secret archives are all that secret: It has opened up the files of controversial World War II-era Pope Pius XII to scholars and changed the official name to remove the word "Secret" from its title. But a certain aura of myth and mystery has persisted—until now. The longtime prefect of what is now named the Vatican Apostolic Archive, Archbishop Sergio Pagano, is for the first time revealing some of the secrets he has uncovered in the 45 years he has worked there, per the AP. In a new book-length interview titled Secretum being published Tuesday, the retiring Pagano divulges some of the lesser-known details of well-known sagas of the Holy See over the past 12 centuries.