VATICAN CITY (AP) — The longtime prefect of the Vatican Secret Archive is spilling the beans for the first time.

He is revealing some of the secrets he has uncovered in the 45 years he has worked in one of the world’s most important, and unusual, repositories of documents.

In a new book-length interview titled “Secretum” to be published Tuesday, Archbishop Sergio Pagano divulges some of the unknown, lesser-known and behind-the-scenes details of well-known sagas of the Holy See.

Pagano delves into everything from Napoleon’s seizure of the archive itself in 1810 to the peculiar conclave of 1922 that was financed entirely by donations from U.S. Catholics.