 Lucas North , formerly known as John Bateman , is a fictional character from the BBC espionage television series Spooks ( known in the United States as " MI5 " ) , which follows the exploits of Section D , a counter @-@ terrorism division of MI5 . North is portrayed by British actor Richard Armitage . The character is introduced in Spooks ' seventh series as the former head of Section D , who was captured and imprisoned during an operation in Russia . He returns to the UK after eight years and is eventually reinstated into MI5 . He is described as having once been the best in his field , and he is now trying to regain his former brilliance . 
