You may not have our best interests at heart, but I won't deny an extra pair of hands. And if Dalaran falls, it takes everything with it--including your Undercity.
So, your benefactor wants in? Fine. I'll imbue your key to work past my wards so you can enter the city. Once you're in, meet me at the Violet Citadel where this all began. With everything going on the Kirin Tor will be too busy to stop you.
Scavenge what you will, but whatever happens, our first priority is to prevent a catastrophe.