When snooty Sandra (Imelda Staunton) discovers that her husband is cheating on her, she escapes from her English countryside manor to London, to the cosy, cramped flat of the free-spirited sister, Bif (Celia Imrie), she hasn’t seen in decades. Sandra seems pretty awful at first, horrible and rude even as she busts her way into Bif’s life, and precisely as we’re about to grumble, “Who the hell do you think you are?” Bif does so herself. And the story settles into a tart, sharp, ultimately life-affirming dramedy that is slightly more edgy and far less predictable than it probably has any right to be. Director Richard Loncraine guides Staunton and Imrie in shaping the surface clichés of both characters into complex, warm portraits of women struggling with getting older and ensuring that they’re making the most of the years they have left, even if they decide they want different things out of them. (Screenwriters Nick Moorcroft and Meg Leonard deserve some of the credit, too.) Uplifting yet never sappy, and with a cast including Timothy Spall and Joanna Lumley, this is an unexpected treat. By MaryAnn Johanson