WoWDB

You must be near Vol'jin in order to use the quest item. It will transport you to the starting area for orcs, which is where Thrall and his family are currently living.

The following letter arrives in the mailbox after using Vol'jin's Hearthstone:

From: Vol'jin
Subject: Darkspear Never Die

My Friend-

Garrosh tried to off me with a dagger to the throat. But I got me something more powerful than assassin's poison. I got friends. You, Chen Stormstout, Thrall... We been through worse.

I need to lie low for a while, get me head together. Chen is taking me to the Shado-Pan Monastery to heal.

Meantimes, I need you to stay close to Garrosh. Keep your eyes open. Find out what he got going on. Dangerous. But I know you can handle yourself. I seen it with me own eyes.

-Vol'jin