The KGB and the FBI both race to track down a vital agent… everything is at stake.

Philip and Elizabeth are thrown off balance when things with Tuan take an unexpected turn. Henry makes a startling proposition and Stan has a disturbing encounter with Frank Gaad’s widow.

In the season finale, Philip and Elizabeth race against the clock as a life hangs in the balance, while Stan faces an uncertain future.

In the aftermath of a disastrous operation, Philip and Elizabeth clash about how to handle things with Paige. Stan struggles to contain the growing risks of Sofia and Gennadi's fraying relationship.

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.

With the arms control summit under way, a shocking revelation from Philip throws Elizabeth - and her work - into turmoil. Stan follows a dangerous hunch.