阿加莎·克里斯蒂被誉为举世公认的侦探推理小说女王。她的著作英文版销售量逾10亿册，而且还被译成百余种文字，销售量亦逾10亿册。她一生创作了80部侦探小说和短篇故事集，19部剧本，以及6部以玛丽·维斯特麦考特的笔名出版的小说。著作数量之丰仅次于莎士比亚。

阿加莎·克里斯蒂的第一部小说《斯泰尔斯庄园奇案》写于第一次世界大战末，战时她担任志愿救护队员。在这部小说中她塑造了一个可爱的小个子比利时侦探赫尔克里·波格，成为继福尔摩斯之后侦探小说中最受读者欢迎的侦探形象。1926年，阿加莎·克里斯蒂写出了自己的成名作《罗杰疑案》（又译作《罗杰·艾克罗伊德谋杀案》）。1952年她最著名的剧本《捕鼠器》被搬上舞台，此后连续上演，时间之长久，创下了世界戏剧史上空前的纪录。

1971年，阿加莎·克里斯蒂得英国女王册封的女爵士封号。1975年，英格丽·褒曼凭借根据阿加莎同名小说《东方快车谋杀案》改编的影片获得了第三座奥斯卡奖杯。阿加莎数以亿计的仰慕者中不乏显赫的人物，其中包括女王伊丽莎白二世和法国总统戴高乐。

1976年，她以85岁高龄永别了热爱她的人们。

during the night on a several day train trip across lower Europe, Poirot's seemingly unpopular sleeping car neighbor is murdered. Rather than little or no clues or suspects, almost everybody aboard the train is a suspect; plenty of clues float around besides. Since the train is totally stalled due to a heavy snow, no resources other than sheer brainpower are available to our intellectual Belgian sleuth. Poirot gets by without his familiar sidekick, Capt. Hastings, but "adopts" a railroad executive and the traveling doctor as foils upon which to foist his evolving theories. After Poirot very cleverly determines that the victim is a hated child kidnapper/killer from America, the plot thickens as the interrogations proceed -- first one and then another and then another of the passengers seem to be related somehow to that long ago famous case. Could it be a conspiracy? You'll be turning the 200 pages rapidly to find out!