Skull Castle (again)

I have taken the lift out of the Labyrinth.... I have entered a room with a brazier. I have turned right, descended some stairs and entered a library... I have picked the lock on the right and found a chest, which I have opened...
But now I have a door on my left that I can not open...
And is this the room where the Lich is supposed to be?

Thanks in advance!!!

[Wyvern]

You cannot open that door - so "forget about it". It only opens from the other side.
To see the lich you need the proper key. This key can be found by going to the tiltling bridge, falling in the water and taking the northwest passage. This leads to a room filled with traps (run for it). The key is on a table on the far side.

The lich is to be found - from the entrance of Skull castle - go up the center stairs and flip the switch to open the gate. Enter the large room with all the warrior ghosts and go up the stairs on the far side of the room. Follow the passage way - first stairs down deadending in a door - that's the door to the lich!
Hope you make sense of those directions!
Wyv