We explore Soviet Lt. Col. Pyotr Popov, who offered his services to the U.S. before being caught. Then, meet CIA officer Chip Beck who refused to evacuate from Cambodia in 1975.

A disillusioned Soviet colonel volunteers his services to the CIA and finds the trump card in a deadly game of nuclear politics; a CIA officer sneaks Stalin's daughter out of Soviet-friendly India.

We see how the CIA caught a spy within its Counterintelligence Division. Then, we examine a bold plan to tunnel under the Berlin Wall where phone lines could be tapped.