Twilight Sparkle's coronation as the sole ruler of Equestria is right around the corner. To not disappoint her, Sunset Shimmer decides to come back to Equestria for the first time since her theft of the Princess's crown to attend.
Said Princess's student, Starlight, is there to greet her, but the two of them are surprised to find that Sunset is a princess herself - or at least an alicorn, and her arrival may have unintended consequences for a trio of recently imprisoned villains.