This post is going to have spoilers for “Feet of Clay” by Terry Pratchett, and “As a Thief in the Night” by R Austin Freeman.
Last week I was browsing in a used bookstore… or, rather, a used-book store… and decided to buy a Terry Pratchett “Discworld” novel: Feet of Clay. Pratchett wrote many many books set on Discworld, they’re kinda zany, very lightweight, fun reading. I’ve read three or four of them over the past few decades and I can’t remember the plot or characters in any of them, but I remember enjoying all of them, so I thought eh, why not. And sure enough, the book was a fun read. There’s a kind of murder mystery, as well as an attempted-murder mystery, and some lovable rogues and so on. The attempted-murder mystery involves administering poison by making candles with arsenic in them. The victim reads by candlelight at night, even as he gets sicker, and over the course of several nights the poison does its work.
I finished that book, and the next day I was walking to lunch on my own and decided that rather than my usual solo-lunch pastime of playing terrible online chess, I would pick up a book at one of the three (!) Little Free Libraries I can pass on the five-block walk to lunch. I had already passed two of them and didn’t feel like walking back, and the remaining one had rather slim pickings, but I was happy enough with As a Thief in the Night, by R Austin Freeman. As you have no doubt guessed by now, in the first third of the book someone is discovered to have died of arsenic poisoning and the police are baffled as to where the arsenic came from, but of course it was done via poisoned candles.
As far as I recall, in my entire life I’ve read only one other story involving poison candles: Edgar Allan Poe’s “The Imp of the Perverse” (I had to look up the title). I assume all subsequent stories with that plot element are ultimately children of that one. ChatGPT in ‘extended thinking’ mode comes up with four such stories: Imp of the Perverse, Feet of Clay, a Marvel Comic from 1983, and a mention of a shop selling poisonous candles in Harry Potter and the Chamber of Secrets. Of course we know that’s not a complete list, since it doesn’t include As a Thief in the Night, and presumably there are some others missing too. But still, I’m pretty sure there are very few published works that include this plot device.
I read a fair amount — I’ve read a couple of thousand books in my life, I guess — so it’s not so surprising that I’ve read a few stories involving poisoned candles. But to read Feet of Clay and then, in the very next book that I selected from a very small choice being given away on the street, to pick up another one… when I reached the point in As A Thief in which the cops start puzzling over how the poison was administered, I thought “you’ve gotta be kidding me. What are the odds?”
“What are the odds” is essentially unanswerable for this kind of thing. Yeah, sure, this particular coincidence was extremely unlikely but a person experiences millions of opportunities for coincidences in their life and some unlikely ones are bound to occur. Also, to mention it just so nobody else has to, almost everything that we experience is ‘unlikely’ just due to statistical mechanics (or something akin to statistical mechanics, just very high entropy): a car passes me on the street, its license place is CNV 1193, wow, isn’t that amazing, what are the odds that that specific car would pass me at that exact location at that exact time, why, it’s unfathomable.
Still, we can acknowledge that there is nothing supernatural about coincidences like the one with the arsenic-laden candles while still enjoying them when they occur.
I have discussed coincidences on this blog a couple of times: https://statmodeling.stat.columbia.edu/2019/12/01/amazing-coincidence-what-are-the-odds/ and https://statmodeling.stat.columbia.edu/2024/11/08/if-you-wanted-to-be-a-top-tennis-player-in-the-late-1930s-there-was-a-huge-benefit-to-being-a-member-of-____-or-to-being-named-____/
I’m not claiming that these are in any way enlightening. And I apologize if hearing about my coincidence is as boring as me telling you about the dream I had last night.