Philip and Elizabeth deal with the consequences of their actions while trying to complete a dangerous, new bio-weapons assignment.
A crucial agent crumbles under emotional distress and threatens to topple a valuable network of KGB informants. Professionally, Philip and Elizabeth are tasked with infiltrating the FBI's new communications encryption system.
A mole hunt within the KGB causes suspicion amongst allies and shatters trust within the Jennings' marriage, meanwhile Stan's plan to keep his mole safe puts her at even greater risk of discovery.
Having revealed their true identities to their daughter Paige, Philip and Elizabeth must keep her best interests at heart while ensuring that they remain protected.
Philip and Elizabeth both find themselves faced with painful turns in their various missions. Stan fights to gain access to an American military program that could give him the upper hand in his battle of wills with Oleg.