KGB: The Sword and the Shield S01E02 - Beria & Co.

By August 1949, at least five years earlier than expected, the USSR became the world's second superpower, thanks to its spies who had stolen America's atomic secrets. But by March 1953, Stalin is dead and KGB chief, Beria, is executed later the same year. Nikita Kruschev tries to reduce the power of the security service, splitting it into several sections...but it doesn't last and, soon, the KGB is back. Abroad, it has pulled off its greatest-ever recruitment coup – a mole at the very top of the CIA.