So I completed the "Su Su Sudrilund" quest and went to see Baldur, then Erik in GH. I got the "Spell Trade" quest. But I can't get in to this guy's cave (forgot his name) to fight him and get my spell. Is there something else I have to do? I re-read the instructions for level 55 spell quests and didn't see any additional info that would unlock the cave. (Note: in my first version of this post I mistakenly identified the quest as the level 35 one).