Walker's Washington contact is identified by Carrie and Saul, but the target is protected via diplomatic immunity. Meanwhile, political bigwigs approach Brody about running for a disgraced congressman's seat.
Elizabeth and Philip come together to deal with a mission gone wrong, but struggle to reconcile their ideologies; Stan welcomes a Soviet defector to America; Nina acclimates to her new living arrangements.
Philip faces a moral dilemma while developing an asset; Philip and Elizabeth's friction escalates; Stan develops a theory with serious repercussions for national security; Paige makes a surprising birthday wish.