Speak to Estulan.
Estulan, a powerful and uncorrupt Highborne, has managed to enter the western wing of Dire Maul and has asked for assistance in cleansing it. Regardless of your personal convictions of the Highborne, it is an effort I must support for the good of Feralas. May the wind carry your spirit there with great swiftness.
You will find Dire Maul to the southeast.