After telling the tale of the last of the Horadrim in the Book of Cain, Blizzard is launching another companion book for Diablo 3, the Book of Tyrael. Just as Book of Cain chronicled the thoughts of Diablo’s talkative elder, the Book of Tyrael is “an in-depth look into the mind of the Archangel Tyrael,” a prominent character in the series.

The book promises “never-before-known secrets” about the Diablo universe and will feature original artwork. It will also include writings written from the perspectives of both Deckard and Leah Cain and “a fully removable family tree.”

The Book of Tyrael will be released on October 1 for $40. The only catch is you’ll have to stop playing Diablo 3 to read it.