A Spooky Passage                                       -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      -     SE

This section of the caverns is noticeably colder than all the others, and
since you'd already become quite certain that the mountain is actually a
volcano.  There is a strange humming noise reverberating throughout the
passageway, making the hairs on the back of your neck stand on end.