在濒临海边的一间房子里，雷文斯克罗夫特将军夫妇双双毙命，是凶杀，还是自杀？两具尸体之间有一枝左轮手枪，枪上的指纹已经模糊，这件事情似乎与将军年轻漂亮的女秘书有关。 Crime novelist Ariadne Oliver again turns to Hercule Poirot, this time to solve a case the police consider closed. Olivers interest in the murder-suicide of General and Lady Ravenscroft is more than academic: Celia Ravenscroft is her goddaughter. This is one of Poirot's most daunting cases even he begins to doubt he can solve it since the investigation relies on memories from years earlier.