Andrea 'Andy' Sachs, an aspiring journalist, lands a job as an assistant to Miranda Priestly, the editor-in-chief of a high fashion magazine. Andy endures the eccentric requests of her boss, while trying to adapt to the fashion world and maintain her personal life. She faces challenges, including a deteriorating relationship with her boyfriend and the choice between loyalty and her own morals. Eventually, she decides to leave the fashion industry behind and pursue a career in newspaper reporting.

Miranda's career goes into decline, forcing her to go face-to-face with Emily, now a major executive at a luxury group, whose advertising dollars Miranda desperately needs.