This great whodunnit subverts every expectation. Normally in this genre, subtle clues are scattered throughout the narrative, but in this book the narrator continually breaks the fourth wall to pull the rug out from under me. He lets slip a tiny clue; I get excited and think I can now work out what’s going on; but then I am deflated as the narrator highlights the clue and says it’s not relevant.
Often in this kind of story, there is a murder in some situation (a cruise ship, a snowed-in mansion) where none of the suspects can escape – it’s a pressure cooker where the actual killer becomes desperate and the bodies start piling up. In this book, though there is a snowstorm, the narrator does point out that nobody is trapped there, they can leave anytime they want. Another expectation subverted.
Another standard mystery feature is that there is an initial murder mystery, but more crop up surprisingly in the course of the story. In this case though, our narrator helpfully lists all of the deaths early on, complete with page numbers where they will occur. It’s like a conjuror who lets you look up his sleeves before his performance, and also in his bag, his pockets and inside his hat. And then still manages to make a rabbit appear from somewhere.
The preface lists the Ten Commandments of Detective Fiction, as used by the writers of the Golden Age of detective stories. Essentially they say the writer should play fair, without suddenly introducing ad hoc elements or otherwise changing the rules. Strangely, I thought, rule 5 was completely omitted, with a note to say it is outdated. I looked it up: the rule was, “No Chinaman must figure in the story”, which was supposed to prevent writers from lazily introducing mysterious, inscrutable characters to explain away implausible plot points. When the rules were first drafted, apparently this role was often taken by shady Chinese characters. I think the rule is still a good one in its intent, but it should be updated to be more broad. I thought it funny that Stevenson squeamishly avoided even quoting the old rule.
Anyway, Stevenson managed to stick scrupulously to the rules and still made an engrossing mystery. Overall I found the family dynamics complicated but it all came together in the end, and I even did actually pick up one or two actual clues. I didn’t figure out any of the puzzles until they were revealed, but it all seemed plausible and the denouement was quite satisfying. Stevenson has written quite a few books – I will definitely read the follow-up, Everyone on This Train is a Suspect.