A Narrow Mountain Pass                                 -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      -      -

As you step from the burnt forest, your footing gives way and you slide
down into a narrow mountain pass.  You pick yourself up and realize that the
sides of the pass are far too sheer for you to climb.  The only thing you
can do is follow the pass and hope you can find another way back to the
forest.