The random dungeon generator for the battlefields sometimes incorrectly places the entrances in partially obscured or even inaccessible locations. Can you toss a teleporter stone through the wall (save first) to get past it? If the layout allows, try standing at the northwest corner of adjoining walls (there is a gap there that might be usable to toss a teleporter stone through).
There are some books that are quest related. Maybe keep anything that seems somehow unique, and toss any you didn't require when you get to the next act.
In the temple, a witch will ask you to get a book from the Raanaar library. After you have that quest, talk to one of the librarians near the entrance.
