As graduation approaches, the crack in the portal to Equestria grows into a gaping hole, unleashing more magic than ever. Thus, it's up to Sunset to stop the flow of magic with her friends and determine which world she belongs in for good.

Christmas is approaching in Canterlot City, and the girls notice how lonely Sunset Shimmer is during the holidays. Can they give her the best Christmas ever?

Starlight Glimmer has been granted a few extra days in the mirror world, and is set to explore the strange sights around her with newfound friends like Sunset Shimmer by her side.