The series tells the story of Sophie Foster, a twelve-year-old high school senior with the ability to read minds. She has always felt alone, until a mysterious boy named Fitz Vacker shows her that there is a place where she belongs, and staying where she is will put her in terrible danger. She is forced to leave behind everything she has known and start a new life in the Lost Cities. Only then does she realize that she was given extraordinarily powerful abilities — and deadly secrets hidden in her subconscious — that some may kill for.