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.
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 German assassin has been ordered to kill American scientists involved in the ABM program. After the mission is aborted, Phillip and Elizabeth must stop him and prevent a possible war, without having any idea of his identity.
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.
In Moscow, Viktor Zhukov is assassinated in the escalating tensions between the two countries. When Elizabeth learns that her personal mentor has been murdered she risks everything to avenge his death.
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.