After struggling to have a child, married lawyers Claire and Zach enlist the help of their friend, Liz to be a surrogate, and she successfully gives birth to baby Owen. But when their surrogate-turned-nanny disappears under mysterious circumstances, the couple struggles to take care of their newborn without any help. Soon thereafter, though, a woman claiming to be the surrogate's childhood nanny offers to be the couple's new nanny. Desperate for help, the couple agrees to hire her, not realizing that their new nanny plans to take their baby for her own family....