You can find a map here:
http://beyond.divinedivinity.net/help/act1_citadel03.htm"There are two lights but you do not see"
Beneath number six are two torches on the wall. Between them is an entrance to a secret way you can use to avoid the traps in the main corridor. I believe you have to blow out a light or pull a lever to open the exit on the other end of the secret passage.
To continue, you have to pull the lever (on number 10) and then the door in the southeastern corner of that room opens (beware of the traps!). Then continue on to number 11 for the next level.