When Dr John Watson takes rooms in Baker Street with amateur detective Sherlock Holmes, he has no idea that he is about to enter a shadowy world of criminality and violence. Accompanying Holmes to an ill-omened house in south London, Watson is startled to find a dead man whose face is contorted in a rictus of horror. There is no mark of violence on the body yet a single word is written on the wall in blood...

林内特·里奇维被一颗子弹打穿了头颅，尼罗河之旅的宁静也因此被打破。这位年轻，美丽，时尚——拥有一切的女孩，最终失去了自己的生命。
赫尔克里·波洛的耳边回响着早先一位旅伴的话语：“我真想用我那把亲爱的小手枪顶着她的头，扣动扳机。”然而在这异国他乡的场景中，一切并不像表面显示的那样平静……