A Drainage Pipe                                        -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

There are small ledges on both sides of the tunnel, just large enough for
you to walk on.  However, due to the water, they have been eroded in some
areas.  The air is thick and moist.  There is a stream of water running down
the center of the tunnel.  You pray that you do not fall in for the water
does not look too inviting.  Slowly, something floats by and brings about a
very strong oder.  The echoing noise has gotten stronger.  
     A gas line runs along the top of the pipe here.