It's 1985, and Mikhail Gorbachev is the new, young leader of the Soviet Union at a very tense time. While both sides have hopes of peace, they have been publicly stockpiling nuclear weapons for decades. Neither side wants to appear weak. Thatcher and Reagan hope that fresh leadership in the Kremlin will offer an opportunity for constructive dialogue.

Top double agent Oleg Gordievsky is pivotal in these negotiations, but a sudden summons back to Moscow by his KGB bosses has unnerved him - do they know he is secretly spying for Britain? When he arrives at his Moscow flat and discovers that a lock which he never turns has been used, his fears are confirmed.

Including exclusive audio recordings of Aldrich Ames, audio interviews from Oleg Gordievsky and interviews with former KGB, CIA, FBI and MI6 officers, including one of the MI6 officers who rescued Gordievsky. Other interviews include colleagues of Thatcher, Reagan and Gorbachev, and experts with personal connections to the story such as Susan Eisenhower and Nina Khrushcheva. Show less