When Rainbow Dash is in a terrible accident and looses her ability to fly Twilight decides to make a Element of harmony powered suit, that anypony could use, and when Rainbow Dash's in it she is the iron pony, helper to all of Equestria. Some ponies(or assassins) might do anything to get their hands on the suit one of them being a jealous unicorn named Dark Hoof who wants to destroy all happiness...