An Extremely Hot Tunnel                                -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

The "Spearhead" opens up into a hallway carved from quartz crystal. 
Unlike the Spearhead, however, this tunnel is extraordinarily hot.  Touching
the walls with bare flesh would cause severe burns, and your vision
continues to waver.  Some great magick lies ahead.