An old pony wanders into Ponyville and promptly gets mugged by a pair of no good Diamond Dogs, Rainbow Dash, seeing the ensuing scuffle, which ends when the old pony incapacitates the two dogs without so much as raising a hoof, he catches Dash's attention, getting him a place to stay at Applejack's farm, Rainbow Dash and Applejack begin to train under him, with the two Diamond Dogs seeking revenge against the old pony and any who may shelter him. Where will this lead, will Dash's competitive nature and Aj's stubbornness ruin their friendship, and what will come of the Diamond Dogs?