When I give the Scroll of Banishing to Adrianna, should I take the key, or the ring? If I take the key, where the heck is the treasure vault??? I can't remember or find a vault I haven't been to or can't get into...

I still haven't found a keyhole for the key (it isn't the level 12 lock in the Lich's study); the hintbook seems to suggest something vague about a vault deep inside the castle.
So that leaves the ring I guess. Hope you have the patch when you put it on; otherwise the game will freeze. Ah well, you can always sell it.
And of course there IS a way to get both: (NOTE spoiler coming)


when Adrianna fails using the scroll, you can try to kill her buddies before they kill her. Then you can pickpocket the scroll from A. and give it again!