Extras is a young adult science fiction novel written by Scott Westerfeld. The novel was published and released by Simon & Schuster on October 2, 2007, and is a companion book to the Uglies series. However, Extras differs from its predecessors in that its protagonist is fifteen-year-old Aya Fuse, not Tally Youngblood. Despite the fact that Youngblood is not the main character, she still appears in the book's later chapters in a major role. The book was received well by critics such as James Hynes.