In post-war London circa 1950, Hester Collyer is the younger wife of a respected High Court judge, Sir William Collyer. Their marriage is comfortable but lacks passion. Hester becomes involved in an affair with Freddie Page, a handsome but troubled former RAF pilot, haunted by his wartime memories. The relationship plunges Hester into emotional turmoil. She abandons the stability of her marriage and comfortable life, moves into a modest lodging with Freddie, and gradually becomes isolated and vulnerable. At one point she attempts suicide by gas at her new lodging, overwhelmed by despair and the realization that her affair and her choices may have destroyed more than they gave. Through flashbacks, the film explores how she arrived at this breaking point. The story is as much about Hester's intense longing, the consequences of her decisions, and the social constraints of 1950s Britain, as it is about the affair itself.