9 year old Frankie and his single mum Lizzie have been on the move ever since Frankie can remember, most recently arriving in a seaside Scottish town. Wanting to protect her deaf son from the truth that they’ve run away from his father, Lizzie has invented a story that he is away at sea on the HMS Accra. Every few weeks, Lizzie writes Frankie a make-believe letter from his father, telling of his adventures in exotic lands.