ya, about that. I was very curious so I went into red mountain with the guy who hasnt annoyed Yagrum yet, and got those books. heres what they are for. SPOILER!
you need them ofr the second wraithguard. as far as i can tell it has the same magical properties as the first one... but it is for the left arm. You kill vivec, get his unique artifact, bring that and the books down to the good old chubby spider, and he will make a second wraithguard. sweet. but! you need to bring very very many fortify health potions.... dont know if you are interested, but its fun.
