Michelle Miller is a chronic sleepwalker. She and her husband Dan Miller are trying to have their first child after she had a miscarriage the year before. One night she sleepwalks into the bedroom of her neighbor Luke Williams while his wife Nancy is out of town. They have sex; she is unaware of this but he not only knows about it but falls madly in love with Michelle and decides he wants to leave Nancy for her. Michelle gets pregnant, but doesn't know whether the baby is Dan's or Luke's.