Starlight Glimmer has finally done it. She has stolen the cutie mark of everypony in Equestria and shown them the path to equality. From her new home in Princess Twilight's castle, Starlight rules Equestria, pushing everypony towards happiness and equality.

But one day Starlight Glimmer encounters a mysterious filly. A filly who is immune to Starlight's cutie mark-stealing magic. A filly with no name, no family, and no past. A filly who refuses to wipe that creepy smile off her face. As the filly begins to make friends with everyone in Ponyville, Starlight searches for a way to beat her. And what does the filly want from Starlight?

She just wants to break her.