Liverpool, 1958: nursery nurse Irene Miller falls for her friend Peggy's handsome older brother, Marty. But he is trapped in an unhappy marriage. Meanwhile, Irene's friend Peggy is desperate to marry her long-term boyfriend, Pete, but Peggy's staunchly Catholic parents would never accept a Protestant son-in-law.
When her mother decides to remarry, her brother heads off to sea, and she loses her job, Irene feels utterly alone in the world. An unexpected job offer from America offers her a lifeline. But it would mean never seeing Marty again. Will Irene and Peggy ever solve their problems by running away - or should they follow their hearts back home to Liverpool?