Annie Braddock (Scarlett Johansson) isn't sure what she wants to be when she grows up but with college behind her, she's got to set herself on a path. She isn't ready for the corner office in the financial district, and her mother (Donna Murphy) doesn't understand. Aimlessly trying to find her way, Annie bumps into Mrs. X (Laura Linney), an ultra-wealthy high society lady and is offered the job as nanny to the X's son Grayer (Nicholas Reese Art). Thinking she has found a temporary respite from the career rat race, Annie accepts. Her best friend Lynette (Alicia Keys) thinks she's crazy as she watches Annie jump into her new job with hope and enthusiasm. Annie quickly discovers why Mary Poppins never landed in Manhattan. Grayer is all but invisible to his parents. His mother is busy chairing benefits and shopping and Mr. X (Paul Giamatti) is an angry workaholic who finds any and every excuse to be away from home. All alone, Annie must give Grayer the nurturing he needs so desperately. Although she knows she must get away from the X's for her own sanity and survival, she falls in love with Grayer and cannot find it in her heart to abandon him.