British agent Alec Leamas refuses to come in from the Cold War during the 1960s, choosing to face another mission, which may prove to be his final one.

After years of having her letters to her estranged father come back as undeliverable, a young woman takes a job at a Dead Letter Office. She hopes to figure out how to locate her father. Unexpectedly, she finds a potential romance and begins to learn more about herself.