A Chartreuse Tunnel                                    -      N      - 
(-------------------------------------------------)     - <---(M)---> -
 WARNING: You are in a NEUTRAL PLAYER KILLING room.     -      -      -

As you continue down the tunnel, the hideous yellowish-green shade of the
rock begins to grow even brighter.  You turn to look back, but you realize
that the path has shifted somehow, leaving only a massive stone archway to
the north.  There is obviously some kind of magic at work here, since such
passages could not have been created by hand.