Euh? I didn't need to pull a lever or anything?
At level 16, I went back to the vampire hole, to see if I could kill him, I lockpicked the gate, went in, and he appeared. Not behind a coffin or anything. He was able to fight me and all. I just killed him, it was easy...
I didn't even have to use much spells, only one or so (don't remember which one, maybe frost or something). Oh,and maybe a few heals,i don't know.
But what has the coffin and a lever to do with this?