Nine-year-old Frankie and his mother, Lizzie (Emily Mortimer, Young Adam), have been on the move ever since Frankie can remember. Wanting to protect her deaf son from the truth that they've run away from his father, Lizzie has invented a story to satisfy her son's curiosity. Regularly, Lizzie writes Frankie a make-believe letter from his father, telling of his adventures as a merchant seaman in exotic lands. However, with his father's make-believe ship arriving in a fortnight, Lizzie must choose between telling Frankie the truth or befriending a stranger (Gerald Butler, Phantom of the Opera) to fulfil her son's need for a father...