本片改编自阿加莎·克里斯蒂的同名小说。 Poirot(大卫·苏切特 David Suchet 饰)到访伊斯坦布尔之际,替英国军方解决了一起复杂的案件。在返回伦敦的途中,他遇到了老友国际客车公司的董事Bouc先生,他为Poirot在最后一刻订到了东方快车的车票。在列车上,Poirot遇到美国富商Samuel,他告诉Poirot自己的生命受到威胁,愿意支付重金让他保护自己,但却遭到了Poirot的拒绝。第二天清晨醒来之际,Poirot发现列车受困于暴风雪中而Samuel已被人谋杀在包厢里。在Bouc先生和Constantine医生的协助下,开始对凶案展开调查,他是否能顺利解开这桩扑朔迷离的惊天大案呢?Railway director and fellow Belgian Monsieur Bouc secures Poirot a last minute berth on the Orient Express, returning to England from Istanbul. Ratchett, an abrasive American businessman, traveling with his valet and male secretary, tries to secure Poirot's services as he fears that his life is in danger. Poirot turns him down, but the next morning, whilst the train is stuck in a snowdrift in Serbia, Ratchett is found stabbed to death. There is vague talk of a man seen fleeing the train, but many of the passengers in Poirot's compartment do not appear to know either Ratchett or each other, so what could the motive be? Poirot, assisted by Bouc and Dr. Constantine, attempts to find out.