在这部蓝色特快上的秘密剧情/悬疑/犯罪片中,在一辆开往法国尼斯的蓝色列车上，一个美丽的富家女惨遭杀害，随身的稀世红宝石也不知所踪。她的丈夫，情人，交谈者都成了怀疑对象。大侦探波罗碰巧也在车上。他发现这是一桩蓄谋已久的罪恶……
After traveling on the Blue Train from Calais to Nice, Hercule Poirot is pressed into service to help solve the murder of heiress Ruth Kettering who is found savagely beaten in her compartment. She was the daughter of wealthy industrialist Rufus Van Alden and very much wanted a divorce. Both her husband and her lover were on the train but she had changed rooms with another passenger, Katherine Grey, so the question naturally arises as to whether she was the intended victim. Grey may also have had enemies as she had recently inherited a very large sum of money and greedy relatives had suddenly taken a interest in her. When an attempt is subsequently made on Grey's life, this appears to the case but Poirot methodically sifts through all of the clues to determine the motive and identify the killer.
比宝石锋利，比鲜血艳红。这列车不如东方快车，多了。。被称为阿婆的四大名著之一，又是火车，这次不是东方快车，而是蓝色特快！。
