During the winter break after the Friendship Games, Sunset Shimmer considers a much more resourceful potential use for the magic mirror in front of the school. She enlists the human world's Twilight Sparkle to help her execute her master plan. Only, in practice she forgets that the portal is, well, a portal. And their cover story keeps getting in the way of their objective.

Crossover with the Buffyverse, taking place the year after the Angel finale and a few weeks after Friendship Games. Twilight has been adjusting to her new situation with Sunset's help. When a new student named Dawn Summers arrives at Canterlot High, the Mane Seven begin to uncover a dark connection between their new friend and the mysterious fates of Sunnydale and Los Angeles. Now they must work to keep their own magical secret.

What are the Elements of Harmony? Along the road to answers, everything thought to be known about magic will be brought into question. Sunset and Twilight are going to need all the help they can get.