Help in Mzanchend

[Xehh II]

Ok, this is a Morrowind question, hopefully some of you still play it.

Ok, here it goes, while walking around Molag Amur, near Galom Daeus I found a Dwemer ruin called Mzanchend to the north-east, I entered the ruin to find the usual guards and a lower level called Mzanchend-Galom Daeus Corridor, while exploring down here I found an entrance to Galom Daeus, unfortunatly it was barred from the other side but there was another door leading to a place called Mzanchend Abandoned Halls, I try to go through the door and it says I need a special key, does anyone know where this key is?

I also found a Mzahnch key that I'm going to try out now.
Turn's out the Mzahnch key is useless.