End of the Tube                                        -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

Finally reaching the end of the lava tube, the brightness dims as the
lava stream cools to a blackened cinder.  The tube slopes down slightly and
smells of fresh lava.  The tube is dark ahead and makes progressing further
into the cave that much more difficult.  Ahead, a dim intersection can be
seen.  
A giant humanoid, with skin as hard as stone wanders the corridors.