Perilous Interference: Why Not to Get Involved in a Christie Investigation

*Spoilers* 

One of the stranger Poirot novels is Peril at End House. Poirot helps a young woman who he is believes is being stalked by a killer...only to discover that she was playing him the whole time. She's a murderer. 

How far did Poirot's interference inspire and aid her? If no one had picked up on her hints--"Someone is trying to kill me"--would she have still committed the book's primary murder?

I tackle this problem in an earlier post: "Detectives Who Cause Deaths."

The problem here is less about the ethics and more about the writing. 

I think the murderess may have still committed the murder: she is something of a sociopath. And Poirot is susceptible to damsels in distress. Still, the issue points up the plot's weaknesses. 

In sum, my prevention detectives would simply need to warn the murderess's cousin--the true target--to stay away. And I don't think they would need to witness the murder first in order to rewind and issue the warning. Objectively-speaking, simply asking around would expose the young woman's mercenary nature and her less than respectable friends. The cousin staying away is good sense. 

The book isn't one of my favorites precisely because so much depends on Poirot not questioning the young woman's motives. And Christie appears to side-step Poirot's accountability at the end. 

On the other hand, Christie appears to have set up Poirot deliberately. She explores detective compliance in other books. When does interference actually create more problems? 

Ordeal by Innocence directly addresses this question. Arthur Calgary returns from a trip to discover that a young man he gave a ride to years earlier was hung for a crime committed during the time the young man was with Calgary. He insists on investigating, only to discover that actually the young man did plan the crime. Calgary's investigation stirs up a lot of unhappiness and exposes one of the young man's victims. The book is a more solid mystery than Peril since the detective's culpability is addressed upfront.

As I mention in the earlier post, Dorothy Sayers also tackled an investigation having unintended negative consequences. In Gaudy Night, when the professors accuse Wimsey of harassing people forced to commit terrible deeds due to social inequity, Wimsey responds by asking them to consider his "real" victims--the people killed while he was investigating, usually from fear of exposure. The question of when and when not to get involved continues throughout the book, up to Harriet's choice between a "safe harbor" (where "real world" events impinge only through the mind) and an "unsafe" life/marriage with a complicated guy, where the outcome is less sure.

Neither Christie nor Sayers argue that Poirot and Wimsey shouldn't be involved. They are pointing out that getting involved may have a cost. (My definition of a non-Mary Sue is that non-Mary Sues eventually accept that cost instead of having their "safety" preserved by the author no matter what.)

My prevention detectives have a mandate to stop murders. That doesn't mean they can't be careful and wise about how they go about it. They are more likely to be careful and wise if they understand and accept the possible ramifications.