The Image of Archmage Aethas Sunreaver at Agmar's Hammer has asked you to become Attuned to the Ley Lines of Northrend.
By now you must be wondering where Dalaran is and how to get there. I can help you with this if you can survive a simple test.
Before I teach you how to teleport to our great city, you must attune yourself to the ley lines of Northrend. Otherwise, you will destroy yourself in the process!
Take this attunement crystal and use it in the pit under the surge needle at the Moonrest Gardens to the southwest. Then you will be ready to learn what I have to teach.