A young American woman takes a job as a nanny in a remote English village, soon discovering that the family's eight-year-old son is a life-sized doll that comes with a list of strict rules.

Young at heart graduate student Becca strikes up an unlikely friendship with Emily, a quiet girl who recently lost her mother. With every passing play date chaperoned by Emily's father, Becca helps Emily come out of her shell and cope with her loss, and Emily teaches Becca to take on adult responsibilities. When a romance develops between Becca and Nate, though, the two must learn to balance their new relationship with Nate's responsibility to Emily, and with Becca's responsibility to finish her education.