When Philip and Elizabeth are given an urgent task to plant a bug in Defense Secretary Caspar Weinberger's office, they risk exposure when an unwilling maid of the Weinberger home refuses to cooperate. Stan closes in on a member of the Soviet Rezidentura in an effort to uncover the identities of deep cover Directorate S operatives.

When an assassin attempts to kill President Reagan, Philip and Elizabeth scramble to handle the fallout within the KGB. Meanwhile, Stan pressures his source within the Rezidentura to find out if the KGB was responsible for the attempted assassination.

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 while personally they are forced to grapple with one of the darker aspects of life as a spy.

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.

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.

Elizabeth makes a shocking discovery about Kate. Philip pursues a contact for information about stealth. Stan continues his pursuit of the illegals.

Martha and Clark’s marriage meets its most challenging test yet. As pressures on Philip intensify, Elizabeth turns to Gabriel with a difficult request. Nina receives a new assignment that reconnects her with her past.

Philip and Elizabeth deal with the fallout of all they’ve wrought. What will happen when the FBI finds out about Gene’s suicide? How will Pastor Tim deal with the revelation that they are Russian spies? And will they be able to handle a dangerous, new bioweapons assignment?

Philip tries with increasing desperation to get rid of a sensitive and dangerous package as family tensions in the Jennings House reach a boiling point when Paige shares a secret of her own.