Speak with Rabine Saturna in the village of Nighthaven, Moonglade. Moonglade lies between Felwood and Winterspring, accessible through a path out of Timbermaw Hold.
For this task, Keeper Remulos' majordomo in Moonglade - Rabine Saturna - seeks aid in exploring the vast wastelands far to the west of Tanaris and Un'Goro. He is located in Nighthaven, the main village of Moonglade.
I want to impart on you the importance of your presence. There are growing tensions between the night elves of Darnassus and the Cenarion Circle in Moonglade. Look beyond racial boundaries and tap into the wisdom of your ancestors in dealings with the Circle there, <name>. Good luck.
