For once, Twilight's life is actually going pretty well. After the fight with Tirek, things are being restored nicely, and Twilight is content in her new life as the Princess of Friendship.

But she soon learns that her castle is being shared by a tiny guest who begins sending her notes, things begin to change. With a new friend by her side, what can go wrong?

But just housing this guest puts both of them in danger. Something sinister is lurking, and Twilight is about to find out what. Together, Twilight and her new friend must embark on a dangerous journey to reverse an ancient spell…or risk losing her friend forever.