The Spirits Have Voices

The Spirits Have Voices shows that you have appeased the ghosts of the Thunderlord Clan by returning their artifacts.

Objectives
Garm Wolfbrother has told you where the Mok'Nathal, Rexxar's people, live. Speak of this to Rexxar at Thunderlord Stronghold in the Blade's Edge Mountains.

Description
, now that you can see me, there is something you must tell Rexxar. I know that he seeks his people, and I know where they are.

The Mok'Nathal, as they are known, have a village to the east beyond the Razor Ridge.

Go, give Rexxar this news. His people are in danger, and I know that he will want to come to their aid.

Details
You can only see Garm Wolfbrother when you have completed the quest The Thunderspike. He should be right next to Rokgah Bloodgrip.

Completion
What is this you speak of?

Garm Wolfbrother? He was the last chieftain of the Thunderlord clan. If you have communed with his spirit, then it must be true.