“I will now lecture on the general mechanics and development of the situation which is known in detective fiction as the ‘hermetically sealed chamber.’ Harrumph. All those opposing can skip this chapter."
"The Hollow Man"
Ever since Dr. Fell made the utterly shocking confession that he's in fact a fictional character in a mystery novel, we have seen more people, fictional or otherwise, thread in the good doctor's footsteps and take a look at the mystery genre in general, rather than a specific problem in a specific novel. Dr. Fell's locked room lecture provided a now infamous classification of how locked room murders could be achieved in tales of mystery and imagination, for example by making it seem like the crime happened earlier or later than thought, etc. The notion of attempting a taxonomy of a certain trope in the genre (that is, the locked room murder or impossible crime) is actually quite interesting, as it freely admits that there is no such thing as pure originality, and it is a clear confession that most of the time, every single idea in mystery fiction is just a variation of something else, some admittedly more inspired than others.
On the other hand, the possibility of a taxonomy also emphasizes the game-like element of the genre, I think. I have mused over "winning the game of a mystery novel" before, but I think that efforts like the Locked Room Lecture really show this element very well for this particular form of game. A well-designed videogame for example, will present obstacles and problems for the player to conquer and more importantly, build on that as the game continues. To take the famous level 1-1 from Super Mario Bros.: the very first section of the level, the game first teaches you can 'jump', it will show you can 'jump on an enemy' to defeat it, and that you can 'jump higher if you hold the button longer'. What follows afterwards are increasingly difficult variations on these notions: you might be asked to jumped consecutively, or beat multiple enemies, or do tricky jump combinations of various heights. The further you progress in a game, the harder it gets. But the thing here is: the game is designed knowing that you have cleared the previous obstacles. A good stage design knows you are in the possession of certain skills and the knowledge of how the game world works ('jumping on an enemy kills it') and how objects and enemies move in a game. In short: it teaches you to recognize patterns, and in a way, that is what mystery fiction also does. As the Locked Room Lecture shows: most examples of this particular sub-genre can easily be identified as a varation of a certain pattern. If you, as the reader, want to "win" this intellectual game, you need to be able to recognize the pattern being used despite all the misdirection and apply your knowledge to this particular version of the pattern.
The plot device of having a character in a novel suddenly hold a lecture about a certain trope in the genre can feel a bit pretentious, but I think it works if you take mystery fiction to be a game of wits. Going back to Super Mario Bros.: say you make it to stage 8-3. I can, assuming you didn't use the special warp pipes or had someone else help you, perhaps assume you have played the previous levels and overcome the obstacles and problems presented there. I can therefore estimate how good you are at the game (at least good enough to do X). That is a different story with a novel: Carr is not likely to know how much you know about the mystery genre, or locked room murder sub genre, if you pick up The Hollow Man. It could be the very first novel you ever read, or just the last in a decennia-long diet of only impossible crimes. The in-novel lecture can thus function as a gauge: by presenting the patterns, the author openly shows the difficulty level they are working at, allowing the reader/player to estimate their own position. Is this author operating at a difficulty level much higher than what I used to, or is it just right? So I am quite fond of these kinds of lectures.
There have been many writers after Carr who have played with the Locked Room Lecture (Amagi made a typology and example stories for each category), or more specific examples of the impossible crime like Nikaidou Reito's Footprints-in-the-Snow lecture. I happened to have translationed one on locked room murders myself even, with Shinji, one of the characters in Abiko's The 8 Mansion Murders, agonizing the suspects and the police as he babbled on about his own locked room lecture, heavily inspired by Carr's. Shinji also refers to a famous essay by Edogawa Rampo by the way, where Rampo doesn't just attempt to categorize the tricks behind locked room murders: Rampo decided to categorize every single trick from mystery fiction. I don't have a full translation of the essay, though I do have a short translation of the various categories Rampo identified. As mentioned in that post, Rampo also has an interesting taxonomy of unique motives featured in mystery novels.
But I have to say, I am infinitely more partial to in-novel lectures on genre tropes, rather than standalone essays. And I also think it's not a secret that I'm actually not so singularly focused on locked room murders and other impossibilities as some of the other mystery bloggers around. Therefore, I'm usually very fond of lectures on mystery tropes other than locked room murders, even if you don't see them a lot. Granted, not every type of mystery works really well in a taxonomy. The 'list-up-all-the-characteristics-of-the-culprit'-type of whodunnit as championed by authors like Queen, Arisugawa and Aosaki for example doesn't really lend it well for it, though I have made a feeble attempt in the past by sketching an idea for a typology for clues used in these type of stories.
But to mention a few other interesting typologies: Arisugawa's The Moai Island Puzzle (disclosure: I translated the English version) features a very short Dying Message Lecture by Maria, which I quite like because the dying message itself is a trope that is often used as just a minor touch to a mystery story, seldom taking the spotlight. Mitsuda's Kubinashi no Gotoki Tataru Mono has a very unique and specialized one, as it is about the topic of decapitated bodies. I mean, once you start thinking about, you'll quickly realize that a taxonomy of this trope is quite possible (the question being why a body is decapitated) as there are a few variations, but it's still a surprisingly original lecture topic.
I didn't really have a point to make in this post, but "hey, I like lectures" but to finish with some more thought-provoking, I thought I'd add in a translation of Arisugawa's categorization of alibi tricks. The alibi is of course a very important notion in mystery novels, and is often also a crucial element of "true" impossible crimes, as well as semi-impossible crimes ("He couldn't have done it because he was seen elsewhere at the time of the murder") and variants. Arisugawa's lecture is featured in his 1990 novel Magic Mirror, and unlike his usual Queenian efforts, this novel is actually more inspired by the work of Crofts, explaining the lecture. And I haven't read it yet, though I will eventually, of course.
Anyway, if you have something to say about lectures on any trope of the mystery genre, or perhaps the alibi lecture specifically, leave a comment.
ARISUGAWA ALICE'S ALIBI LECTURE
(from: Magic Mirror (1990))
1. THE WITNESS HAS ILL INTENTIONS.
- The witness is intentionally lying.
2. THE WITNESS IS MISTAKEN.
a. Mistaken time.
- The watch of the witness has been tampered with; mistaken day of the week or date; etc.
b. Mistaken location.
- The witness is mistaken about the location they were with the culprit (the exact apartment, train, mountain, river, etc.)
c. Mistaken identity.
- The culprit had someone impersonate them.
3. THE CRIME SCENE IS MISTAKEN.
- For example the crime is committed in the mountains of town A, but the body is moved to the mountains of town B to make it seem like the murder was committed there.
4. PHYSICAL EVIDENCE IS TAMPERED WITH.
- For example the faked photograph.
5. THE TIME OF THE CRIME IS MISTAKEN.
a. Made to look like it happened earlier than actually happened.
- For example the victim is made to appear like they were killed at 2 o'clock, even though it happened at 3 o'clock, and an alibi is obtained for 2 o'clock.
b. Made to look like it happened later than actually happened.
- For example the victim is made to look they still lived at 4 o'clock even though they died at 3 o'clock, and an alibi is obtained for 4 o'clock.
A. Medical trickery.
- The time of the crime is faked through tricks like heating or cooling the corpse, tampering with the contents of the stomach, etc.
B. Non-medical trickery.
Using non-medical tricks to accomplish 5a and 5b.
* Both 5A and 5B feature an a and b variant.
6. AN OVERLOOKED ROUTE.
- For example it takes one hour between points A and B, but an overlooked route between those points is only thirty minutes. This category is especially often seen in mystery stories about train timetables, but one can also think of shortening an one-hour hike from the mountains to mere minutes by jumping off a cliff with a parachute.
7. REMOTE MURDER
a. Mechanical trickery.
- A pistol that is fired through a clock mechanism etc.
b. Psychological trickery.
- Having a person under hypnosis or suffering from conditions like sleepwalking commit dangerous acts on their own.
8. GUIDED SUICIDE.
- Giving the victim such a tremendous psychological shock they commit suicide.
9. NO ALIBI.
- That what the culprit claims is an alibi isn't a real alibi at all, but only said to make other people think they have one.
Original Japanese source: 有栖川有栖 『マジックミラー』