Marlo (Charlize Theron) is the mother of three children, one of whom is a baby who has just been born and is crying for food. Marlo, whose life is completely filled with housework and childcare, feels very suffocated. At this juncture, she received a call from the school, informing her that her eldest son could no longer continue to attend ordinary schools and needed to transfer to special education schools. Under the advice of her younger brother Greg (Mark Duplass), Marlo, who was on the verge of collapse, invited a night nanny named Tully (Mackenzie Davis) to help. At first, Marlo did not trust this woman who looked young, but as time went on, Tully's ability and thoughtfulness captured Marlo's heart. Marlo's life has undergone earth-shaking changes because of Tully's appearance.