The book stays in the Shelf in the Right side when yu walk in its the Seccond one yu have to pass a Disarm Check to Get it.. if its not there reset the entire thing bro.. theres no other way to open the stuff to get the spear..
and its always best to Make the 3 challanges First before go there to take the Spear and Armor.
Then yu go to Yurgir and Slay the asshole or do his quest but its bugged i advice to slay him and get the XP
(another Advide ALWAYS make Manual Saves of Evrything.. this game is quite bugged since 3.0 so just to be Safe.. make always some Safe Spot Safe after this importants stuffs..)
i my games i just Turn oFF auto Save becouse was F. my Frame evry time that shit saved.. so i just gave up on auto save.
Claoud too from Steam i deactivated and the game runs smoother as ever pretty crazy thing...