When the Doctor returns to Canterlot High School with a brand new face, he catches an already startled Sunset Shimmer off guard. After learning about distressing information, Sunset falls into a mild depression, and refuses to tell her friends. When a familiar villain turns up with information regarding Sunset's problems, she takes matters into her own hands, leaving Canterlot High in secret.
Determined to discover what's happening, the Doctor is forced to team up with the one who gave the information to Sunset in the first place, Starlight Glimmer.

'Alternate Universe' tag for many changes in the timeline. Takes place after Friendship Games.