It's 1982, and KGB spy Oleg Gordievsky travels to take up a post at the Soviet embassy in London. The spying game and paranoia magnify the suspicion between superpowers, and an arms race threatens to bring the world to nuclear Armageddon.
With Gordievsky's help, Britain identifies Mikhail Gorbachev as a possible new contender for Soviet leader. He could be the ticket to better relations between East and West. However, fragile steps towards diplomacy are threatened by vested interests.
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, and neither wants to appear weak.
Reagan and Gorbachev prepare for a global summit to discuss future peace; Oleg Gordievsky embarks on an escape plan that could derail all the diplomatic efforts.