Imelda Staunton and Francesca Annis star in a mystery about late-life romance. Claudie Blakley, Russell Tovey, and Lydia Leonard play the grown-up children of Annis’s character. Stephen Rae is her new gentleman friend. Staunton stars as the inquisitive next-door neighbor. And David Bamber is the detective who tries to work out whether an unfortunate incident was an accident or a heinous crime.