Heartwarming drama about nine-year-old Frankie (Jack McElhone) and his mother, Lizzie (Emily Mortimer), who have been on the move ever since he can remember. To protect her son from the truth about his abusive father, Lizzie has invented a story to satisfy Frankie's curiosity. She regularly writes Frankie a letter from his make-believe father who she claims works aboard a ship travelling to exotic lands. However, Lizzie soon finds out his 'father's' ship will be arriving in a few days. Now, Lizzie must choose between telling Frankie the truth and hatching a desperate plan to find the perfect stranger to play the perfect father.