Tinker Tailor Soldier Spy (2011)

In the bleak days of the Cold War, espionage veteran George Smiley is forced from semi-retirement to uncover a Soviet agent within MI6's echelons. In the 1970s, recently retired MI6 agent George Smiley is trying to adjust to civilian life when a disgraced agent reappears with information concerning a mole at the heart of the Circus. Smiley finds himself drawn back into the murky field of espionage. Given the task of investigating which of his trusted former colleagues has chosen to betray him and their country, Smiley narrows his search to four suspects—all experienced, urbane, successful agents—but past histories, rivalries and friendships make it difficult to pinpoint who is eating away at the heart of the British establishment.