A Glowing Mystical Barrier                             -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

There is a somewhat invisible barrier here that prevents anyone who is
not balanced in alignment and a druid to pass.  The glow around the tree of
life seems to be the glow that is given off by this shield that protects the
tree.  You simply can not pass onwards to the north unless you meet the
strict requirements.