This was Agatha Christie’s 8th novel, and the 5th for Hercule Poirot. It came after the work widely regarded as Christie’s best, The Murder of Roger Ackroyd and my favourite Poirot story, The ABC Murders. In a lot of ways, this is “just another” Christie novel, one which doesn’t display her talents to the best effect. The lack of a distinctive setting, characters, or ingenious method of murder, means this work must be regarded as a minor piece. Yet, even then it is not entirely without interest.
The novel doesn’t quite play fair, meaning that there are a couple of key facts in Poirot’s summation that are needed to really clinch and air-tight proof of guilt. Unfortunately, genre knowledge also points fairly directly at one particular suspect fairly early on, a fairly unlikely suspect. Any doubt you might have is clinched by Poirot pinning it down to two suspects early on, one of whom is far too obvious to be satisfactory within the genre norms. This got me thinking about almost every magic trick I’ve had explained to me, and the central through-line of The Prestige. The truth is there, it’s obvious, but you don’t want to know how it’s done. In this case, we have a mystery that is not especially mysterious, and what we enjoy is playing along with that. The truth is rather unsatisfying in its mundanity.
More interesting then, are the characters populating the tale, rather than the tale they’re in. Christie is often accused of writing wooden stereotypes, and in this novel, she offers us a fairly broad cross-section of women. There is the high-strung artist, the avaricious cougar, the level-headed but romantically inclined daughter of same, a couple of maids, a couple of old biddies, and two women approaching the age of respectability. The victim, a woman, is flighty, and making romantic decisions based on the heart, rather than common sense. We could argue that she is killed because of her poor choice of mates, an argument that I think would appeal to Grella’s understanding of the genre. The specific motive given is that she is transporting valuable rubies, and her murder is collateral damage on the theft.
More interesting is Christie’s positive role model, virtually the heroine of the story. She is in her early 30s, having devoted her girlish youth to care for an elderly woman abandoned by her family. She is an observer, and a listener. Christie hints that she has solved the mystery in parallel with Poirot, but either lacks his conviction to follow through, or his experience with criminal matters. She inherits a fortune, and decides voluntarily to give some of that fortune to relatives who play no other role in the story – she evades the classic error of generating or causing a so-called “unfair” will. She has no deep love of fashion, but once she becomes rich, she dresses well, and well to suit her particular style. Style in her is not simply fashion, but an expression of personality. Other women describe her as “not attractive” and that’s how she sees herself, but all of the men in the novel find her desirable. She therefore has genuine modesty. She recognises when people are trying to take advantage of her, and negotiates their advances so that they are mutually benefitted, rather than rebuffing avaricious behaviour “on principle”.
Christie never preaches, per se, but there is a clear conservative moral streak running through this novel, centring around this heroine. Quite a different sort from Tuppence, her first female protagonist, who is impish at best – though with mostly good intentions.
Knowing what Christie wrote afterwards, it is perhaps possible to see The Mystery of the Blue Train as a prototype for Mrs Marple’s approach to crime solving. Marple will meld the avuncular qualities of Poirot with the English decency of Katherine. Marple, far more than Poirot, is Christie’s greatest achievement, which this novel helped make possible.