Philip and Elizabeth feel the weight of a new family secret while following up on the KGB's interests in South Africa; Stan faces struggles both at work and at home; Martha confronts a shocking development.
Martha and Clark's marriage meets its most challenging test yet; pressure on Philip intensifies; Elizabeth turns to Gabriel with a difficult request; Nina receives a new assignment that reconnects her with her past.
Elizabeth and Paige take a trip that lands them in treacherous territory; Philip turns to an unlikely source for solace; Stan's plan to save Nina culminates in unforeseen ways.
Philip and Elizabeth's home and work lives collide in new and dangerous ways; Nina struggles to figure out her next steps.
A dangerous Naval officer becomes the key to Philip and Elizabeth's mission and Stan struggles with the potential cost of protecting Nina.