Daniel embarks on a dangerous quest to bring Viktor home, while Celeste takes a terrible revenge on Stephen. Viv sets her sights on the ultimate prize: 10 Downing Street.

Cast: Emma Thompson, Russell Tovey, Rory Kinnear, Ruth Madeley, Maxim Baldry, Jessica Hynes, T'Nia Miller, Anne Reid, Lydia West, Sharon Duncan-Brewster, Jade Alleyne, Julie Peasgood, Rachel Logan, Tamar Baruch, Mary Nightingale