This quest is not available in game.
Rhonin wants you to go to the Violet Hold in Dalaran and speak with Warden Alturas.
Listen to me, <race>.
It's just been brought to my attention that there's been an incident at the Violet Hold. It would appear that the blues are launching a full scale invasion of Dalaran!
I need you to get to the prison and speak with Warden Alturas at once. He'll give you the details.
That is not all. I need this handled with utmost discretion. We mustn't alarm the citizens of Dalaran if it can possibly be avoided. Do I make myself clear?
Very well. Now, go!