Actor and peace campaigner Mark Rylance finds out what happened to his grandfather Osmond Skinner during the Second World War, a man who spent almost four years as a Japanese prisoner of war. Mark uncovers how his grandfather bravely joined the Hong Kong Volunteer Defence Force with no military training, before being shot on Christmas Day and taken as a prisoner of war. Throughout the programme, Rylance find his views on war tested as he uncovers the real and shocking truth about his grandfather's wartime experience.