Marple is invited to London to see her old friend Ruth. Miss Marple was a sort of traveling companion to Ruth and her sister, Carrie Louise. Ruth is worried about Carrie Louise. She doesn't know why, though. Ruth asks Miss Marple to come with her to her sister's estate, Stonygates. Stonygates is a huge manor house, and…

卡罗琳将嫁给拉尔夫爵士，并邀请她的妹妹芭芭拉做她的伴娘。然而，芭芭拉勾引拉尔夫，她成为了新的女士，但尽管她的新的富有的情况，她感到无聊，转向高速公路抢劫恐怖。在路上，她遇到了一个著名的拦路强盗，他们继续作为一个团队，但有些人开始怀疑她的身份。