Thanks the pointer on the maze experience. I'll hit it on my next go around. Unfortunately, I wasn't able to Persuade the necromancers and they attacked me, and only then was I given the quest, which seems to think I have the other 3 soul jars in my inventory. Do I need to leave the tower and go back to the cavern, and then destroy them (and I thought I already did that when I cleared the cavern, but maybe I only destroyed Trompdour's.)