Even before she started being the caretaker of dreams in Equestria, Luna had always had vivid dreams. "A strong imagination," her sister had always said. But now the dreams are getting weird; they're out of control, in fact. She's starting to imagine strange things... terrible things. Luna knows that the Magic of Friendship can solve all kinds of problems... but when she calls in her most trusted friends and allies, they might just get more than they bargained for.