Maggie Smith is a marvel as Miss Shepherd, the eccentric elderly woman who parked her campervan in Alan Bennett's drive for a few weeks, and stayed for 15 years. Alex Jennings is a joy as Bennett, but this is Smith's film: her comically cantankerous exterior masking an inner sadness. There's fun, too, in the neighbours' perplexed reactions to her mucky presence. This small but big-hearted comic drama is a great alternative to the talking animations and blockbusters that fill the festive TV schedule.