One hundred and fifteen years have passed since Twilight Sparkle became ruler of all Equestria. While her best friends have long since succumbed to time, she remains the beloved Princess that everypony looks up to. Whenever a problem arises, she's there to fix it with the Magic of Friendship. Her School of Friendship has since blossomed into a society that is unravelling the secrets of Magic itself, and she's even considering giving Queen Chrysalis, Tirek and Cozy Glow another chance... considering it, anyway. But on the morning of the 115th anniversary of her ascendency to the Equestrian throne, a mysterious object appears in her castle with properties she cannot wrap her head around.