This is an adaptation of an Agatha Christie play, Black Coffee, which I read a month or two back. It's not written by Christie herself, having been adapted long after her death, but it's very much in her style. It's a straight adaptation of the play, with very little added or altered, so the novel itself is not particularly long, and its main advantage is that it's rather more easily accessible than the play. (It's taken me years to track down a copy of the play - there's one in the Auckland Public Library, however). The novel is much more widely available. And it's enjoyable, too, in exactly the same way that the play was enjoyable: a well-constructed mystery, with Poirot being Poirot. You know exactly what you're going to get, and if it doesn't reach the heights of some of Christie's better work, it's still an entertaining couple of hours.