In the fifth season of the British espionage thriller, Harry Pearce and Adam Carter begin to suspect that members of the British establishment are creating a crisis in order to bring about a change of government. In the opening episodes Juliet Shaw encounters a car bomb, and her life is changed forever. Plus we meet former MI-5, turned MI-6 officer Ros Myers (Hermione Norris), who discovers a shocking family connection to the seasons game-changing conspiracy.