Phillip and Elizabeth Jennings are two seemingly normal Americans who are really undercover KGB agents. After kidnapping a Soviet defector they discover their new neighbor is an FBI agent assigned to their case.
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.
Gregory, Elizabeth's lover, helps them make contact with Robert's widow despite an FBI team. Gabriel's replacement shows up. Phillip then makes a dangerous buy of information.
After President Reagan is nearly assassinated events quickly start to spin out of control. The FBI wonders if the KGB is somehow behind it; the KGB worry that they will be blamed for it and possibly result in war.
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's troubled marriage is further tested when a mission to discredit a Polish pro-democracy leader reunites Philip with his old flame.
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 a New York.
Phillip and Elizabeth shock their children when they announce they are separating. After Amador goes missing, Gaad orders an unauthorized mission to grab a KGB agent in retaliation. Events soon spin out of control and come to a grisly end.
After Amador's murder the FBI begins a massive manhunt for the killer. When they start closing in on Gregory, the KGB decides to send him to Moscow. Despite Elizabeth's best efforts he refuses to go, even if it means his life.
Events in Moscow strike a personal chord for Elizabeth, leading her to take on a dangerous mission she can't complete without Philip's help, and placing the couple on a collision course with both Grannie and the FBI.
An Air Force colonel offers to sell SDI secrets to the KGB. Viola reports the bug in the Weinberger home. Phillip agrees to marry Martha hoping she'll continue spying while Nina confesses to spying for the Americans.
