So, my Altmer battlemage, Kalerien, in Arena is doing a quest for the King of Firsthold to kill a ghoul called Balebinx. Well, problem is I've cleaned out the ground floor, but I can't find the entrance to the floor beneath. There are a lot of trap-doors in the dungeon, but appearantly they're only for decoration. I know the game is very random so it's unlikely someone else has been sent to that exact same dungeon, but I'm hoping some of the Arena veterans can give me some helpful advice.

PS: Do I need some special kind of weapon, like silver, to kill the ghoul?