The Fel Crystals

Objectives
Destroy the Fel Crystals. Provided item: The Heart of Fernus
 * Southern Fel Crystal
 * Central Fel Crystal
 * Northern Fel Crystal

Description
You have the key. Now use it to destroy the fel crystals.

Once they are eliminated, the magical barrier blocking the entrance to the Gloomspire will come down.

And once the barrier is down, you'll go inside to confront Gul'dan.

Rewards
You will receive:

Progress
On accept:
 * say

Completion
The barrier is down. Now it's time to capture Gul'dan.

Gains

 * 13970 XP