This quest is not available in game.
Kill Ambassador Infernus in Angor Fortress and bring proof of his death to Advisor Belgrum in Ironforge.
Ambassador Infernus was sent to Angor Fortress by Ragnaros himself to mind the Shadowforge seeking lost artifacts in Uldaman.
It has already meant tremendous casualties for our people, but it has obviously grown worse. I hesitate to guess how many artifacts they would be able to find and use against Ironforge.
Our goal is simple, <class>. Return to the Badlands and destroy Ambassador Infernus. Once the threat is eliminated, return to Advisor Belgrum with proof of your victory.
It is in your hands now.