I’ve never been eager to see movies based on books, mostly because they never live up to the original, but I’m willing to make an exception when Emma Thompson is the star. That’s how I found myself at a showing this week of The Children Act, an almost-excellent film based on the novel of that name by Ian McEwan.

The film and the book both come to life in the opening scenes. We meet Fiona, a British High Court judge in the Family Division, wrestling with multiple cases that defy easily solutions, even as she’s confronted with a crisis in her marriage. Her husband of 35 years, frustrated by Fiona’s lack of interest in sex, has just demanded that she let him have an affair with a younger woman.