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

As you continue down the tunnel, you notice that the hue of the stone
begins to shift from the normal dark gray to a hideous shade of
yellowish-green.  You turn to look back, but you realize that the path has
shifted somehow, leaving only the tunnel running to the east and west. 
There is obviously some kind of magic at work here, since such passages
could not have been created by hand.