Sunset Shimmer, seeking the source of a keepsake left by an old friend, finds herself at Friendship Academy. However, upon meeting the strange mare, Starlight Glimmer, her life is consumed by the myth of the alicorn and the power of miracles.
The mysterious Table of Harmony has called on Starlight Glimmer to solve a friendship problem at Canterlot Castle, but wait! A second cutie mark belonging to a magically inclined alicorn has appeared, and unfortunately for Twilight, it’s not hers.
Sunset Shimmer has her eyes on Starlight, one of the most popular girls at her new school, but what starts as a plan to save Starlight from her worst enemy/best friend takes on a life of its own, and soon their high school is feeling a lot emptier.
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.
Starlight invites herself back to the human world, and asks Sunset to come along. Anything and everything that follows is entirely on their shoulders. Or maybe not.
Sunset has many regrets, too many to count. Most of them she has managed to atone for. One still remains. Now, it's up to Starlight to help her new friend close the book on her past, just as another did for her.
Twilight Sparkle asks Starlight Glimmer to be the guidance counselor for the School of Friendship. Starlight, understandably, needs time to process this. And maybe a few strong drinks.
Summer in Canterlot is a beautiful time of year. If only Sunset's friends were around. But maybe Sunset doesn't have to spend the day without a friend.