Bring 5 Recovered Tomes and the Worn Leather Book containing The Arm of Gri'lek to Loremaster Dibbs in Southshore.
Those beastly ogres now reside within Alterac's ruins, and I shudder to think what they're doing with the precious books still there. You must recover what you can!
Enter the Ruins of Alterac and search for tomes looted by the ogres. Get whatever you can find and bring them to me, but also seek out one book in particular: The Arm of Gri'lek. It contains ancient troll lore that I must learn, and the Ruins of Alterac was the last known location of an intact copy of this book.