The gates of the underworld are opening for the first time in two thousand years. It's up to Sunset Shimmer, demon hunter extrordinaire, to slam 'em shut.
As punishment for her crimes, the Elements have cursed Sunset Shimmer to do favors for anyone who asks. Lucky her. And then there's that other Twilight Sparkle she keeps running into...
An accident with the Mirror Portal ends up with Twilight stuck as a small pony in the Equestra Girls' world. Her friends can't get over how cute she is.