A Spiral Staircase                                     -      -      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      -     SE

You have come across a stairwell in the castle.  You can feel the air
circulating through the floors in a cool breeze.  The stairwell is dark,
with minimal light coming from slits in the walls used for ventilation.  The
stairs spiral down from here.