Spoilers. There is a delicious score, an elegant and whimsical 1936 waltz, on which during moments of suspense a bassoon plays comic variations. Nothing is to be taken seriously. Certainly not the story. The plot gives us incidents which are evidently red herrings designed to mislead Inspector Poirot but mislead the viewer as well. Why should "the clumsy cliché" of the smashed watch telling us the time of the murder be necessary? Because, says Poirot, it is supposed to lead him to believe the murder took place at an earlier hour than it did, an hour in which all the suspects had unshakable alibis. But if the suspects were in cahoots, couldn't they have improvised the same alibis for a later hour as well? After all, Poirot was asleep in his compartment, or at least trying to sleep, all night. And the lady in the white nightgown with the red dragons -- what was that about? It complicated the plot with an added detail but couldn't have confused Poirot much since it was of no relevance to his perception of what was going on.
The acting isn't meant to be taken seriously either. First, there is Albert Finney as Poirot, who looks absolutely great with every visible hair waxed to perfection, and an indefinable accent that wavers a bit from scene to scene, as if he were, as John Simon put it, "sending up trial Walloons." Everyone else overacts hammily (and enjoyably) too. Especially enjoyable is Sir John Gielgud as the batman or butler or valet or whatever he is, explaining away a "contusion" on the back of his head with, "The result of a fracas in the mess, concerning the quality of a pudding, sir, know as 'spotted dick'."
There were one or two other things in the script that Agatha Christie (played by Vanessa Redgrave in "Agatha") could not have gotten away with. Guilgud also does a marvelous job with the simple act of stabbing his employer, wriggling the dagger from side to side in the unconscious man's chest, and yanking it out with a theatrical flourish and an expression not of rage but of utter contempt. Likewise impressive is Sean Connery as Colonel Arbuthnot, that mess hall accent and demeanor, that mustache more firmly established than the Empire itself, snapping at Poirot that he would not have been stupid enough to use his "peep cleaner" and leave it in the murdered man's ash tray.
The least interesting performances probably include Jacqueline Bissett, Peter York, and some minor characters, but this is partly because their roles require less of them. (How can you be a hammy wagon-lit conductor?) I haven't read the novel in years but my impression is that this movie, with its additional wit, is an improvement.
The elegance of first-class travel on a train whose very name is suggestive of mystery and romance is nicely conveyed. It's snowy and scenic and bitterly cold outside, but in these beautifully appointed compartments we are well and snug and can order fresh oysters and fruit and poached sole with one new potato and a green salad with no dressing. It's cramped of course, but that merely adds to the impression of coziness.
The Orient Express as I experienced it in third class isn't really very elegant. The only space I could find was on the metal floor in front of a bathroom, whose door kept swinging open and shut. Everyone on board seemed to have a digestive disorder. After buying a bottle of home-made chianti from a vendor at one of the stops, for twenty-five cents, so did I. I suppose you have to be well-to, British, and middle class, as Christie was. All her views of the world, gathered in the wake of her archaeologist husband, are tourist's views, which is just fine.
The plot, as always in a Christie story, is as finely tuned as a watch and follows its format as closely as any episode of "Columbo." Poirot meets an old friend in some unusual place. A murder takes place. Poirot interviews everyone and pieces the whole thing together, no matter how improbable the feat. The last chapter (or reel) has the guests gathered together silently while Poirot strides around, or in Finney's case, shuffles around, and explains what has happened and why. The solutions are usually a surprise when they are finally revealed, but repeated viewings don't hurt. In fact, knowing ahead of time what the end will look like gives us a chance to appreciate better the display and character and the planting of clues, real and false. This is nothing more than a divertimento but it is a highly likable one, without pretense, and neatly done.