It's summer 1982, and KGB spy Oleg Gordievsky travels from Moscow to take up a post at the Soviet embassy in London. East and west have a deep mistrust and misunderstanding of each other, and as a result, the Cold War, which has been rumbling on for almost 40 years, is heating up. The spying game and paranoia magnify the suspicion between superpowers, and an arms race threatens to bring the world to nuclear armageddon. Including rarely heard archive interviews with Oleg Gordievsky and the unpublished letters of Michael Bettaney, as well as interviews with former aides to Margaret Thatcher and Ronald Reagan and former KGB, MI5 and MI6 officers, some of whom have never spoken publicly before.