This Christie adaptation was flagged as "in a modern setting, with a contemporary twist". There was so much twist they forgot to tell the story, which is a good one. Characters were introduced briefly, with thumbnail descriptions in voice-over, instead of being allowed to show us who they were. Then the "contemporary, modern" angle was shoved in our faces. "And this is my wife, Alexandra, a high-flying barrister, you know, not like in the olden days when women didn't have jobs, and here's Rosemary's sister, who's a personal trainer to the stars and has a black footballer boyfriend, not like in the book which is old fashioned, twee, quaint and weedy and she's a debutante who possible works as a secretary." Instead of a dashing male detective we have two old buffers obviously based on Christie's characters Tommy and Tuppence - former secret service agents who are occasionally called out of retirement. Of course they have to use computers and mobile phones the second they are introduced, and get themselves offstage with "You shadow the husband, I'll go and DO SOME RESEARCH ON THE INTERNET, you know, that modern thingy that they didn't have when Christie wrote her books I mean in her day they probably sent messages by a man in a cleft stick and were hopelessly dull and oldfashioned and never never did anything interesting like having sex." Actually the original Christie story is teeming with adultery - read the book! Read the book! And then watch the enjoyable 1983 film with Anthony Andrews which has the sense to stick to Christie's story. Updating from the 50s to the 80s, and moving from England to America, makes perfect sense. But avoid the TV version with David Suchet, filmed as The Yellow Iris, which muffs the story badly, introducing an unnecessary trip to wartorn South America (!?) and not even showing the second dinner party (filling in time with an equally otiose "South American" dance rehearsal).
