|Mutually Assured Destruction|
|Air Date||March 20, 2013|
|Directed By||Bill Johnson|
|Written By||Joel Fields and Joe Weisberg|
|Previous Episode||Duty and Honor|
|Next Episode||Safe House|
|Images of Mutually Assured Destruction|
Philip and Elizabeth must stop an assassin from taking out key US scientists, while Stan and the FBI hunt the same man. Grannie shocks Elizabeth with the truth of what happened between Philip and Irina in New York.
Claudia tells Elizabeth about Philip's affair with Irina; Elizabeth decides to be his professional partner only and abandon the "real marriage". Elsewhere, the KGB has hired a West German contractor to kill American scientists, but has changed its mind and cannot recall him. With unwitting help from Philip's informant Martha (Alison Wright), an FBI clerical worker, the Jennings track him down and eliminate him. However, he has already rigged a time bomb that kills a scientist and three of his FBI bodyguards — Gaad vows vengeance. Meanwhile, until Nina can be extracted for protection, Gaad gives Stan the keys to a safe house in which to meet her, which she surmises Stan means to be their love nest. Lastly, after being spurned by Martha, Agent Amador becomes suspicious and starts to follow her.
- "Siamese Twins" (1982) by The Cure.
- "Love Will Find a Way" (1978) by Pablo Cruise.
- "Trouble Blues" (1976) by McKinley Mitchell.