Philip and Elizabeth are given an urgent task to plant a bug in Defense Secretary Caspar Weinberger's office; Stan closes in on a member of the Soviet Rezidentura.
An assassin attempts to kill President Reagan; Stan pressures his source within the Rezidentura to find out if the KGB was responsible for an attempted assassination.
A crucial agent crumbles under emotional distress and threatens to topple a valuable network of KGB informants; 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; 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.