[Randyt]

Is there a way to finish this quest "correctly" without guessing that the Tanner did it? I know once you kill him you find out, but something tells me you should know this before you attack him.

The prostitute tells you the material that the killer used was frequently used by Tanners, so I go talk to him and he is clearly avoiding the issue and not helping (I feel like Lenny Briscoe!). I cast detect evil and he is evil. I then try to go down the stairs next to him and it says 'You cannot go down the stairs with him standing there watching'. So I go back outside, drink a potion of invisibility, go back inside by myself and I get the same message when I try to go downstairs. Aren't I invisible?

Anyone know how to get down there without killing him first?