I was wondering if you happened to remember where you got the key for the locked door, with the keyhole within the center, located within the "Lightning Conduit" section of level 8. I've looked around the area with no luck. Thanks.
If you look at the map, there should be a 3x5 room to the east of the iron door. In the center of that room is a pillar. Use what I mentioned earlier in this room.
Figured it out. In a room to the east of the iron door, you'll see a puzzle similar to the first puzzle on this floor, dealing with the three torches being placed on the center pillar. Place the torches on the opposing sides, and leave no torches on the middle pillar. This will open a secret door le...