Warn Bolvar!
Speak to Highlord Bolvar Fordragon in Stormwind Keep.Description
Although we don't have all the answers we might like, it's imperative that you bring our findings to Highlord Bolvar Fordragon right away!He needs to know that the Defias have a powerful patron in Stormwind and that they're involved in the disappearance of King Varian!
I can use my magic to expedite your trip to Stormwind. Just speak to me when you're prepared to go, <name>.