In 1939, on a royal tour of Dartmouth Naval College, Princess Elizabeth (later Queen Elizabeth II) meets the dashing Prince Philip of Greece. Immediately they begin a correspondence, as war breaks out across Europe, where Philip is sent to serve in the Navy. Elizabeth convinces her father the King, despite his reservations, to allow her to sign up to the war effort and joins the Women's Auxiliary Territorial Service. Serving her country, driving trucks and fixing cars, Elizabeth wonders, will she ever see her prince again...?