一位女演员被发现在一具尸体的旁边，而她又失去了记忆，似乎没有什么能说明她不是凶手。就在法院认定她有罪并被判处死刑的时候，依然有一个人相信她是无辜的，但他能够找出足够的证据解救她吗？
Old miss Marple is on a train ride when she witnesses a murder in a passing train. She reports it to the police but they won't believe her: since no body can be found there can't have been any murder, right? As always, she begins her own investigation. The murder was committed while passing Ackenthorpe Hall and miss Marple gets herself a job there, mixing cleaning and cooking while searching the house for clues.
