It's 1963, and Alison Wilson returns home to husband Alexander - shortly before his sudden death. Blinded by grief and focusing on comforting her two teenage sons (Gordon and Nigel), Alison is bewildered when a Gladys Wilson arrives at the door, claiming to be Alec's ‘real' wife. Alison sets out on a journey to discover who Alexander Wilson really was, dissecting their 1940s romance and her husband's mysterious career in the secret service.