Stella Jones, a popular cheerleader who goes undercover as a spy, is assigned to investigate her high school, but she discovers her true path: to become a spy. In her diary, she records suspicious activities and notes her observations about almost everyone she meets. It seems harmless until one day, the diary is discovered and reveals Stella's critical thoughts about her classmates. Suddenly, even her snob best friend, Mallory Lawrence, betrays her, leaving Stella bent on revenge, and her other close friends, Anton, Daria, Rooney, and Hunter, are helping her to become a spy.
