Before An Elevator Shaft                               -      #      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

This small corridor leads north to a set of double sliding doors.  You
find that it is easy to pull them open, revealing a small wooden platform
beyond.  There are a series of cables and pulleys attached to the platform,
allowing it to be lifted up to the level above.  To the south you can see an
identical setup at the other end of the corridor.