21-year-old Annie Braddock (Scarlett Johansson) has just graduated from Montclair State University. Annie has no idea what or who she wants to be. One day, while sitting at the park, Annie saw a young boy in a uniform about to be hit by a vehicle. Annie saved him and met the boy’s mother, Mrs. Alexandra X (Laura Linney. When she introduced herself as “Annie”, Mrs. X mistaken her words for “Nanny” and hires her to look after her young son Grayer. Annie lied to her mother about taking a job at a bank and, in reality, moved in with the X’s to be the nanny for Grayer, the boy she saved.
Life with the incredibly privileged X’s isn’t all she thought it would be, and her life is complicated further when she falls for “Harvard Hottie” (Chris Evans), who lives in the building. Annie begins to notice that not only is Grayer being neglected, but so is Mrs. X, with Mr. X committing subtly obvious adultery and not treating her like a proper wife.