Speak with Baron Sablemane at the Circle of Blood in the Blade's Edge Mountains.
<name>, while you were out being one hell of a <class>, Baron Sablemane sent his pet dragon up here with a message.
He's asked for you personally. From what I understand, he wants you to head up his own fight against the gronn.
I guess you're the most qualified person in all of Outland to help him, but if I were you, I'd get in contact with a couple of friends first and ask them to join you at the Circle of Blood.