A Sentry Post                                          -      -      - 
(-------------------------------------------------)     W <---(M)---> -
                                                        -      -      -

A checkpoint has been set up here.  Around the top of the staircase is a
barricade forcing all foot traffic into a single file line.  A small handful
of heavily armed guards have been tasked to check everyone wishing to enter
this section of the Keep, looking for spies and other troublemakers.  The
rumors about what happens to those without proper identification are rather
frightening.  Best have your papers ready.