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.

Philip and Elizabeth are finally assigned a new handler as Philip works to clean up the mess of the last operation and Elizabeth, in disguise as Clark's sister Jennifer, does her best to smooth things over with Martha. As Stan searches for a missing scientist, Oleg and Arkady continue to argue over how best to handle the situation on their side, leaving Nina once again caught between the FBI and KGB.

Tensions simmer between Philip and Elizabeth as they disagree over handling orders from the Centre. When Elizabeth loses key intel, Philip enlists Annelise on a mission with an unexpected outcome.

The Centre rushes to prepare Martha's exfil as Directorate S agents try to locate her but, it seems that a backup transport was also ordered. FBI tears up the Clark Westerfeld apartment. Martha almost walks into the FBI dragnet. Philip is overcome with self-recrimination...KGB may kill Martha. The FBI intercepts a call to Martha's parents from Woodley Park and stake out the area. Philip gets a call from Rock Creek Park; Elizabeth races to reach her and brings her in bruised but alive. Oleg does not know why backup transport was ordered. Gaad waxes philosophical about his FBI career in flames as the Jennings kids drink beer with Stan's son. Philip is finally honest with Martha, over Elizabeth's objections. Martha knows that she will be completely alone in Moscow. Will tomorrow's plane carry one rat or two? Or will Martha bite the Valium bullet and refuse to be forced to defect and commit further treason?

The Jennings hit their breaking points as they try to handle their local agents such as Martha.

When Paige's long-ago indiscretion threatens to resurface and destroy the family, Philip and Elizabeth find themselves scrambling - and Paige finds herself reevaluating who her parents really are.

As Paige deals with last episode's trauma, she sees her mother in a new light... and finds she has inherited some of her parents' skills. Plus, has Oleg reached his breaking point with Stan?

A sudden assignment pulls Elizabeth away from her family at a crucial moment. At the FBI, a major development leads Aderholt to approach Stan about an urgent investigation.

Phillip goes to Chicago to help Elizabeth complete her mission; Stan's suspicions grow.

Philip tells Elizabeth about his connection with Burov, Elizabeth uses the young intern to listen to an important meeting after the original plan fails.

Elizabeth chooses a side in the internal soviet fight, meanwhile Stan's suspicions of Elizabeth and Philip get stronger.