Last Tango in Halifax: Season FourCatch up with the lives and relationships of reunited childhood sweethearts Alan (Derek Jacobi, Vicious, The Kings Speech) and Celia (Anne Reid, Upstairs Downstairs, Bleak House) and their family members in this warm and witty two part special. To Celia's dismay, Caroline (Sarah Lancashire, Happy Valley, The Paradise) takes on a challenging new headship role at a troubled state school and buys a rundown farmhouse nearby. Is there more to this big