Word to the wise, after defeating the librarian sometimes he doesn't drop a book. Now, before you go psycho on me there are two factors:
1) if some one in the party is not on the quest AND it's their turn to loot in the loot order you will NOT get the book
2) Only one book drops at a time.
Solution? Set to free for all loot, jump down the side of King's Breach once you enter (to your right) pull the two pats + one lizard for simplicities sake, kill, rinse, and repeat until everyone has the book.
My partner and I are still shard firsts on this but hopefully this will help others with frustrations. Already bugged it as it should pop up for everyone on the quest like the blade of life did in the level 20 cult saga quest.