Of the three TV movies in which Peter Ustinov starred as Hercule Poirot (the other two being "Thirteen at Dinner" and "Murder in Three Acts"), in my humble opinion "Dead Man's Folly" is the most entertaining and suspenseful one; the script is marvelously close to Agatha Christie's novel, the cast is quite good for US TV standards, and the setting is a real old British manor, elaborately decorated, which tries to give the film a feeling of 'Old England'. BUT unfortunately, just like in the other two TV adaptations I mentioned, the producers obviously refused to create a REAL 1950s' atmosphere (the novel was written in 1956), and instead let the actors wear contemporary clothes and hairstyles of the 80s (and even use mobile phones!) - probably because that was what the audience wanted...
Anyway, as far as you can overlook those anachronisms (or in case you don't even notice them), this movie has got a very high entertainment value - mostly thanks to the protagonists, Peter Ustinov, Jean Stapleton as Poirot's highly imaginative writer friend, and Jonathan Cecil as Hastings. There's some nice humor in it (probably also for the sake of the TV audience; because in tone, the novel was quite a bit darker...), and it's a REAL murder mystery: the complicated plot unfolds slowly, and if you pay good attention to every detail and every word that's being said, you may be able to guess the murderer before Poirot presents the solution. If you're not too particular about the authenticity of the wardrobe, hairstyles, cars and music, this is an enormously enjoyable crime puzzle for every fan of the genre!
