The Book of Truth was found by the Stranger in Ultima IV in the library of the Lycaeum, under the letter "T" for Truth. The Book was one of the three keys to open the Abyss. It is not clear what happened to the book afterwards, but it was most likely returned to the Lycaeum library. In Ultima IX the Book of Truth was again found in the Lycaeum, and the Avatar was allowed to take it after admitting responsibility for the evil that had befallen Britannia. The book was later used by the Avatar to free Shamino from the Ethereal Void.
Its further fate is unknown.
- The Keyring Mod by Marzo Sette Torres Junior adds the Book of Truth to the Lycaeum in Ultima VII.