The "Hitting the Books" quest isn't going to be completed for me because he won't leave his cell, even when I unlock it with a key and talk to him. All I can say to him in dialogue is "I've got what I came for." Is there a simple solution for this, or what? I've tried opening and reopening his cage, leaving and entering the dungeon again, talking to him from outside the cell, etc., but nothing has worked. What can I do about this so I can keep on with this questline (with saving him too)?