A shocking revelation from Philip throws Elizabeth - and her work - into turmoil.
Philip and Elizabeth come together for an operation unlike any they've ever had before.
A sudden assignment pulls Elizabeth away from her family at a crucial moment.
Elizabeth enlists Philip's help for a mission that could yield game-changing intel.
Elizabeth is forced to go to extreme lengths to get close to a Soviet negotiator.
Philip and Elizabeth clash about how to handle things with Paige.
Elizabeth pursues an old source who could help with the upcoming summit.
An arms-control summit is on the horizon and Elizabeth is pushed to the limit.
Philip and Elizabeth race against the clock as a life hangs in the balance.
Philip and Elizabeth grapple with a momentous decision.
A surprise assignment from the Centre divides Philip and Elizabeth.
Philip and Elizabeth make a choice that could shift the balance of their lives for ever.
Stan has a disturbing encounter with Frank Gaad's widow.
A secret brings Elizabeth and Paige together.
Philip and Elizabeth's honeytraps take surprising turns.
Gabriel stuns Philip and Elizabeth with a sudden announcement.
Philip and Elizabeth receive shattering news about a past operation.
Philip and Elizabeth have qualms about a new assignment.
Philip and Elizabeth tell Paige more about the family business.
Stan and Oleg wrestle with the harsh consequences of their complicated history.
Philip and Elizabeth struggle to contain the risks from Paige's relationship with Matthew.