I'm stuck in the Maze of Madness. I've managed to figure out the first 3 portals to take, but now I'm in the NW corner of the room, near the key, and none of the portals seem to take me any further. Help would be appreciated.

Solved! Thank you! :D

Those teleporter puzzles are a great fun even if it could sometimes be frustrating.
I was kind of stuck the same way and I decided to check if the teleporter behaviors were stable.. I couldn't find my way with all the teleporters and their destinations mapped, and then I begun to suspect the teleporters could change their previous destination if another one was triggered first, changing the probable sequence. Tricky heh?
Next I thought the side you enter the teleporter (it has 4 sides) could change the destination too...
It wasn't that twisted, but that may be in the expansions ;)
I just missed a detail but searching for a solution was hard but entertaining! Love that!
Don't think too far!

There's a little room on the south-west corner of that Maze : how to get there ? I got the key already...

On this same level, there's a trapdoor with a demon face firing fireball on the other side. How to get past this ?