A Dark Tunnel                                          -      N      - 
(-------------------------------------------------)     - <---(M)---> #
                                                        -      -     SE

The air here is very hot and humid.  You can see your reflection in the
condensation on the walls.  The smell of sweat, grime, and blood whisks by
your nose, making you queasy.  From a cell farther ahead, you hear someone
groaning in misery, and others follow his lead.  Above your head, a board
creaks, and some dirt falls down, narrowly missing you.  A thick iron door
is set in the east wall, with a small hole on the front.  
     A well-worn shovel has been stuck in the ground here.
A smelly mold is stuck to the wall.