This quest is not available in game.
Archmage Lan'dalock in Dalaran wants you to return with a Ley Line Tuner.
This quest may only be completed on Heroic difficulty.
The Nexus War rages on and we must do something to turn the tide! Are you willing to fly into the heart of the battle, <name>?
Ley-Guardian Eregos is the protector of the conduit through which Malygos is funneling the magical power of Azeroth's ley lines. If he can be slain it will be a great blow to the enemy.
Please bring me one of his ley line tuners so that we might study it.