Set in Leeds in the Fifties Cold War period, Billie Piper stars as Betty, a young wife and mother who reluctantly falls passionately and hopelessly in love with her charismatic Polish neighbour, Alex Crazenovski, played by Theo James (new Woody Allen film, untitled). But little does Betty know that some 30 years later, in Eighties Thatcherite Britain, her affair will implode on her beloved son Mark's wedding day. Mark as an adult is played by Andrew Lee Potts (Primeval). Sue Johnston (The Turn Of The Screw, Waking The Dead), stars as Betty in the Eighties opposite Alun Armstrong (New Tricks) who plays her devoted, if dull, husband, Donald. The younger Donald is played by Alun Armstrong's real-life son Joe Armstrong (Robin Hood). Frances Barber (The Street) plays Betty's sister, Margaret, who is always there for her sibling through thick and thin, and in her younger years aided and abetted Betty's affair. Rachel Leskovac (Coronation Street, Holby City) plays Margaret in the Fifties.