This Folio is a sealed on, containing some scrolls of great age. The scrolls will be of a language of great antiquity. Some of these scrolls might be cut up and pressed flat into a leafed book.
If you can read the scrolls, which usually require a language known to religious scholars, you will find a collection of works from the time of a holy man who is the foundation of current religion. These are notes, letters, and “unreleased” scriptures from the holy one and his disciples. After reading these work, you come to the understanding that the current church is not following the true wishes of the holy person… that the orthodox view is wrong… corrupt even… or what we believe to be true is totally wrong.
An ancient scroll in Aramaic: The Last Will and Testament of Jesus Christ… giving directions to all his disciples (which lists a few different names than the accepted ones) and goods going to his wife and son, the rest going to his synagog congregation.
Confession Scrolls telling of some of the miracles being hoaxes (He really did not rise, we just said he did) by one of the minor figures in the holy texts. And the paper from the Old Government denoting his suicide.
Pieces from a personal journal that tells how certain “religious miracles” were carefully staged with a bit of magic and some ingenuity.
Historical papers from the Old Empire that refutes the mythological/ scriptural account.
Sciptures from The Great Sage that explains he made all this up, but it is all allegory, rather than real.
Creation myths and holy prayers that are different, but somewhat similiar, to the orthodox one. So while the orthodox one shows that men should dominate women, and there is a racial order to the universe (elf/ human/ dwarf/ orc/ and lesser races), the real one shows that women should be in charge of most of life and that their is a spiritual order, not racial order to souls. In short, the foundations of the religion is wrong.
Or some other holy scripture from long, long, ago, that blows the orthodox religion of the time apart.
The cultist could of been studying it, could of been holding it for safe keeping for the cult, or it could be a carefully constructed hoax.
Some people are looking for it to “save it” and present it to the public.
Some groups are are looking to destroy those papers, lest their secrets be revealed.
Some organizations want them for their own purposes, to use them as leverage against either of the two previous types of groups.
And Secret Dark Cultists trying to steal it back from you, because it is theirs.
Note: This books is also known as the DarkStar Codex.