John Skillpa (Cillian Murphy) is a clerk in a bank in Peacock, Nebraska. He also has an alter ego who is a woman named Emma who usually appears in the morning to do the household work. One morning when Emma is in the house, a train caboose has an accident and breaks into his backyard. The public that reaches there believe Emma to be John’s wife. Scared of letting people know about his alter ego, John tries convincing them that Emma is his wife. However, Maggie (Ellen Page) who is a single mother living there knows John’s secret and the fact of his abusive mother which brought out the alter ego. John struggles with Emma and Maggie for the control on his life.