A Turn in the Passage                                  NW     -     NE 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      -     SE

The ceiling and walls become smooth with artificial reinforcements. 
Wooden beams supporting the path line the walls.  The air and stones become
drier, as water doesn't pour in from above.  The passage turns on an almost
right angle with a distinct change in climate.  Darkness shrouds the passage
ahead and behind.  
A small golden creature scampers around the ground.