Stuck in Skull Castle

I have the key of bone and am trying to get to G'Ezerred Ras chamber. I have got to what appears to be the antechamber which looks like a library with a lecturn in the middle but the door to the left which leads to his chamber wont open when I approach it and I can see no mechanism. There is another door to the right with a lock. I bashed this open and it just contains a small room with a chest in. I have tried approaching the chamber from the other side but again the door doesnt open when you go up to it. Please help as I cant get any further. I have thrown the wall switch at the north end of the bridge to stabilise it but that didnt help either.

[Davros]

This key you have - did you get it from atop the altar in the small room with all the death head spells that fly at you?? This is the 3rd of 4 directions you can take when swimming from the bridge room (ie going from left to right you have Adriana, Doshi Ginn, the Lich Key room, and the maze. It's not the key you found in the maze is it. I opened the door from the front incidentally, never managed to open it from the treasure room side. Hope this helps .

[Wyvern]

You're in the wrong location. That unopenable door in the library can only be opened from the other side so forgetaboutit.

TO find the lich - get yourself back to the entrance of the castle - go straight up the stairs and flip the switch to open the gate, walk through the big room with all the warrior ghosts, take either stair way on the far side - take the exit at the top, follow the corridor until you come to stairs going down - go down, open the door with the key - visit the Lich!

Have fun!

Wyv