A Large Tunnel                                         -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

You are walking through a small dark tunnel.  At the far end, a light
beckons you closer.  The air is musty and damp, there is no telling when
this cave was last explored.  You notice the smell of burnt charcoal and
numerous scorch marks run across the cave walls.  
A large stalactite is dislodged from the ceiling, narrowly missing you!