All right, I understand that this film is not like the book. Having not read the book, I can only say that I thought the movie was quite fun. I enjoyed watching and trying to solve the mystery. I got the right answer, but for the wrong reason. Oh well....
The story is modernized, but still has that quirky Agatha Christie feeling. The story centers on the poisoning of Rosemary Barton, the trophy wife of George, an older man who proves money can't buy class. The Bartons host a celebration of a football victory. When Rosemary is poisoned the guests are the prime suspects. Those guests include; Iris, Rosemary's sister who is a fitness guru to the stars; Lucillia, Iris and Rosemary's aunt; Ruth, George's long time devoted, but mousy, PA; Fizz, the football striker who doesn't get enough respect from George, and Stephen and Alexandra Faraday. Faraday is a high placed government official who has a troubled marriage. Because of Faraday's presence when Rosemary is offed, the PM brings in Kate and Geoffrey Reece to investigate and do any needed damage control. The Reeces appear to be ordinary grandparents, but are in reality government operatives. The Reeces are witty with conversations peppered with affectionate bantering.
Kudos to outstanding acting by Jonathan Firth, James Wilby, Pauline Collins, and Oliver Ford Davies.
No, this is not going to be the greatest movie you've ever watched, but it's fun watch on a lazy afternoon.