Anna's new friend, Emma, is everything Anna wants to be-fearless, effortlessly fashionable, and always up for doing something fun. The girls even look alike, and soon they're fixing their hair the same way and sharing clothes. But Emma is also kind of a troublemaker. She likes to sneak off school grounds at lunch, and she doesn't seem to like Anna having any other friends. Emma never seems to get caught, but Anna does. After all, they look just alike. When Emma's sense of adventure takes a sinister turn, Anna starts to worry. Is her mirror-image BFF a dangerous evil twin?