TV drama starring Billie Piper as a woman whose passion overpowers her pragmatism and sees her embark on an affair with her neighbour. Set in both the 1950s and 1980s, the drama follows the affair itself and its legacy. In the 1950s, Betty (Piper), married with children, puts aside a life of duty and self-containment and embarks on a passionate affair with her Polish neighbour, Alex (Theo James). In the 1980s, with Alex dead and the affair supposedly undiscovered, an older Betty (Sue Johnston) is busy organising her son (Andrew Lee Potts)'s wedding. But can something as passionate and life-defining as her affair with Alex remain buried forever?