London 1941. When Mary meets a glamorous stranger named Elizabeth she realises their lives couldn't be more different. Elizabeth is beautiful; and charming, about to set off on a dazzling adventure to Ireland where she's inherited a grand house. Mary, shy and meek, has nothing to look forward to but the dreary life of a maid in Hampstead. But when an air raid forces them to take shelter underground Mary's life is set in change forever. After waking up in hospital, injured but alive, the nurse mistakes her for Elizabeth and hands over Elizabeth's suitcase with her money and tickets to Ireland inside. This is Mary's chance to escape the hardship of her life and start afresh. But you can't run from the past forever.