To obtain this one-time quest, you must have an average itemlevel of 481 or higher -equipped- (and you have to relog if you didn't originally meet the requirements on login). This is different from the requirements for a heroic scenario, which just require itemlevel 480 -overall-.
Complete any scenario on Heroic difficulty.
My mind is spinning with boredom - I never get to leave this place!
You look like you've seen some adventures. If you can bring me a truly heroic story, I've got something special I'm sure you'll be interested in.