Long ago the Hero sealed away the evil that threatened the peacefulness of the land. Knowing that the evil would one day return, the Hero put a piece of himself into his sword so that whoever had a good heart and intentions would one day be able to wield it and help them on their quest.

That day comes when one of the Cutie Mark Crusaders, Applebloom, finds the sword and awakens the spirit of the Hero, along with the darkness that had been hidden away. Now it is up to her to save Equestria from the darkness of old and save her friends.