The Book of Occult Mysteries was one of the books given to the leaders of Wayland by The Wizard.
When Lyrith touched the book, a rune on his hand began glowing and later exploded, destroying his hand.
Magnus Godrikson skimmed through the book for about four hours while many of the kingdom leaders were having a bar fight in Rockstern Palace. He noticed there were no chapter headings, no table of contents, and no index. It appeared to be a smattering of different articles. The articles varied in content, but were generally evil how-to guides, stories of evil things people had done, and a rare few articles on how to prevent evil things. Magnus' general impression was that reading the book for any prolonged period of time would make the reader evil.
One slightly useful bit of information that Magnus was able to glean from the book was that evil beings could be destroyed by summoning an angel or "creature of light".
Due to the likely risk of reading the book in-depth, and the sheer amount of time needed to get useful information out of it, Magnus decided to set the book down and devise a more effective strategy for getting information out of the it. After three days, the book disappeared.
Magnus asked the rest of the party if anyone knew where the book was, then consulted the chief cleric of Wayland and asked him to prepare a divination spell to help locate and destroy the book. The cleric asked the following questions on Magnus' behalf.
Cleric: "I plan to destroy The Book of Occult Mysteries within the week, and to give up if I cannot succeed within that period of time. How important is it that I succeed in this task?"
Divination: "Evil is evil, though the task is just."
Cleric: "Where is the Book of Occult Mysteries currently located?"
Divination: "By who you most trust, and which has given you no lie, but only for a short time."
Cleric: "Which kingdom or empire is the book currently located in?"
Divination: "A kingdom near, a kingdom pure, it knows lots of troubles, but will push on."