Murder on the Orient Express is two mystery tropes in one: (1) there's a common trope where you have a group of people in a confined space with no means of escape for the murderer and a murder that must have occurred during a small window of time, meaning that everybody is a suspect. and (2) there's also a trope – one that I tend to this of this book as the original example, or at least what it is famous for – in which everybody did it. But a key detail – and a third trope – in Murder on the Orient Express that somehow, to my surprise, I didn't remember is that Poirot lets them get away with it. Perhaps this is common in the "everybody did it" genre of murder mysteries, because I think in these stories – as is the case in Murder on the Orient Express – the group of people has come together to exact justice on a bad guy, a baby killer in this instance, whom the formal justice system has let go free. Poirot rarely allows the perpetrator to escape justice. In the TV show, the closing scene of many episodes is the moment the murderer is hanged.* (These hangings always seem violent in the context of the show and I've always assumed this was a comment on capital punishment.) So, the message of this book is that the real perpetrator isn't the 12 murderers in the book, but the murderer they murdered.
I watch a lot of murder mysteries and I'm always fascinated by the ones where the murderers are allowed to get away with it. I think probably this happens more in the stories centered around gentlemen detectives rather than police. Father Brown, for instance, lets an alarming number of people get away with murder – after they've made their peace with God, of course. But Poirot, as a former policeman, seems to usually share the bias of the police that murderers should be formally punished. So perhaps Murder on the Orient Express is a bit of an outlier in this way.
In any case, I'm pleased to report that this was an enjoyable read – even already knowing who did it.
