http://www.youtube.com/watch?v=R5o7k...eature=channel
After this i went to check this out myself on the Night elf i was just leveling in Darkshore
Only on the alliance side of this 'secret quest' you get a quest item off that Demon Hunter.
After this you get neutral with the Cenarion Circle and after turning it in you'll get an Achievement called Ghosts in the Dark
Writings of the Void