Duty Calls: Battle of Britain, throws you deep into the heart - and horror - of Britain's darkest, and finest, hour. Pilot officer Archie Jackson, 19, is in control of the RAF's newest fighter aircraft, a Supermarine Spitfire. Now he has the Luftwaffe in his sights and only one thing matters: defending Britain. Suddenly planes are falling from the sky, exploding and spiralling into the English Channel. France has fallen and the swastika flies over Occupied Europe. Only these young pilots - barely out of boyhood - stand between Britain and a Nazi invasion . . .