The Face on the Milk Carton by Caroline B. Cooney

During one lunch day, Janie Johnson was eating her peanut butter and jelly sandwich. She suddenly got a craving for milk, even though she had just found out that she was allergic to it, and grabbed her friend's carton. She finished it and glanced down to see who was missing that day (the milk company posted pictures of missing children on their cartons) and instantly recognized the picture. She thought about it for a minute and realized that it was her picture! She was missing! This book is definitely a page-turner. It's a little freaky, but it's still really good. This is the story of a girl who is in search of her real self. - Apeksha V.