終わり Week 9 of 十角館の殺人🕵️‍♀️ Mystery Novel Book Club 👮‍♂️

Hello and welcome! We have entered the ninth and final week of the book club for 十角館の殺人! This week is coming a bit early because I’m going to be traveling and won’t be able to post at my regular time.

As a reminder, we are following the below schedule (page counts are estimates based on standard size iPad with default font):
Week 1 + 2 : プロローグ + 第一章 (47 pages)
Week 3: 第二章 (31 pages)
Week4: 第三章 (24 pages)
Week 5: 第四章 (22 pages)
Week 6: 第五章 (39 pages)
Week 7: 第六章+第七章+第八章 (43 pages)
Week 8: 第九章 (55 pages)
Week 9: 第十章 + 第十一章 + 第十二章 + エピローグ (52 pages)

I will generally copy this information over thread to thread each week for ease of finding - you can always expect the schedule at the top of any weekly thread :slight_smile:

:policeman: Law and Order :policewoman:

  • Any reveals, for the current chapters must be behind spoilers or detail curtains. When we get further in you don’t need to hide details that were revealed in previous chapters.
  • Questions on vocab, grammar, nuance, and the like are both welcome and encouraged. If you’re not sure if it’s a spoiler, assume it is and use one of the above options to hide the text.
  • You are encouraged to speculate and guess wildly
  • Be kind about other peoples’ wild guesses :sparkling_heart:
  • Even if you don’t read the chapter(s) in time, you are still encouraged to post in the thread for that reading once you have finished it. I advise not reading ahead in the threads as you may see spoilers.

To gauge participation - a poll!

Are you reading week 9?

  • Yes, I’m planning to read along/am reading along this week
  • I have finished this week’s reading
  • I’m reading, but not at the same pace as the club (am behind or ahead)
  • I’ve stopped reading
  • I wanted to join, but I haven’t started reading the book yet
  • I had no intentions of reading the book, but I desire to click a poll

0 voters

Happy sleuthing! :male_detective:


I am kinda pleased with myself… while I did not know the how or the why, I did suspect the right person. :partying_face:

My current theory is Van. I think he might be faking his illness
Week 7 of 十角館の殺人🕵️‍♀️ Mystery Novel Book Club 👮‍♂️ - #3 by Biblio


Thanks, I over-eagerly read the first two chapters.

I am wondering after seeing the cigarette chart, if that’s going to be relevant. Out of the last 3 only ヴァン smoked Seven Star, so maybe an out of place cigarette butt?


I have also finished! Once I got to the reveal I couldn’t stop myself until I reached the end. I am kind of annoyed at myself because I remember when reading the section just after ルルウ dies I was like “hmmm, ヴァン is reacting very extremely here, something is up :thinking:” and was suspecting him for a bit before I must have been diverted to suspecting someone else. Totally didn’t see the twist that ヴァン and 守須 were the same person though!

For some reason, I think I was under the impression that where 守須 and the other mainland detectives were was much further from the island than it turned out to be. I found the explanation of how it all went down pretty satisfying. Poor foolish エラリイ …. I kept thinking that at various points it would dawn on him but nope.

At the very end I was kind of confused for a while as I had totally forgotten that the murderer wrote a letter/judgement and threw it in the sea at the very start. I think I would have preferred that one of the others actually figured it out, but it’s another nice homage to ‘And then there were none’ I guess.

All in all, I really enjoyed this book and reading everyone’s theories made it even more fun!


Okay, I haven’t finished the book yet, only the first chapter of this week, but I need to scream into the void for a sec :joy:

Major spoilers up to the end of chapter 10 (the reveal™)

Oh my god.
I can’t find the post right now but didn’t someone here even say something like “If 守須had gone with them, wouldn’t that have created a room issue since there are only 7 bedrooms?”
Gah, that was such a big hint in hindsight :joy:
I just thought it was a plothole or something.
And I even speculated that us not knowing the killer’s real name was gonna be relevant, and 守須 going back and forth between the island and the mainland was a theory that people here have brought up… all the pieces were there :sob:
Somehow I still didn’t at all think of 守須 possibly being the same person as someone else on the island.
Well I feel sufficiently dumb already, time to read on :joy:


All done!

Huge kudos to eefara (no @ so as not to spoil them before they finish) for suspecting, even in passing, that ヴァン and 守須 might be the same person. Also huge kudos to the manga that managed to show both and yet trick me into not noticing the resemblance. I kept thinking that there is no way this can be turned into a movie without instantly giving away the biggest spoiler, but given the way the manga played me, who knows.

I do have reservations though. There are so many ways the plan could go wrong, I don’t even know where to start. The risk of being spotted, even in a remote location, even at night, is huge. People do go to isolated locations all the time, for various reasons. Not to mention that in a quiet natural environment, the sound of a boat engine can be heard from very far away. The risk of the students chatting about him waiting on the island for them before they left, or during the boat trip, was also big. It wasn’t impossible for people on the mainland to have heard that he was expected to be on the island. The fact that no one was given sleeping pills, yet everyone was expected to sleep like the dead through the night, never wake up to go to the toilet or just because they are in unfamiliar surroundings or nervous, or just a night owl, is also crazy. The fact that he managed to strangle a girl without her making a sound is not something you can count on either. The fact that he committed no mistakes during the first two days while being actually feverish after self-induced dehydration and basically sleepless, is also a bit hard to swallow. And I’m sure there’s more. Oh well.

Also, do we suddenly not care about the body in the secret room? Are we satisfied with the crime of passion + suicide story for the first island massacre? Or did I miss something about that?

In any case, it has been great fun reading and speculating with all of you! Thank you all, and @cat especially for running this club! :smiley:
Looking forward to everyone’s thoughts on the ending, and to our next book, whatever it may turn out to be!


Finished up yesterday :tada:

Those last words from イラリイ… he really was convinced it was 中村青司 until the very end.

This was a fun book, tempted to look into the next one :thinking:


Yeah, I had some similar reservations which is what was actually pointing me towards thinking it would be a) someone we thought had died, or b) two people working together. I think for me between Van being spotted by LeRoux, almost being caught by Poe’s suggestion they search the rooms, and having some level of explanation for why people probably wouldn’t disturb him randomly once he’d gone to bed (because they all thought he was sick) - was just enough for me to accept the overall implausibility of the plan, but I can totally see why it would be too much of a leap. It definitely adds more weight to the evidence that Ellery is a very poor detective :laughing:


I mean, poor Ellery was operating under the impression that he was up against a super intelligent master criminal. Van’s master plan had so many holes that it’s a wonder he could pull it off. I too had dismissed some of my own theories as too risky and therefore unlikely. All that said, yes, Ellery had more enthusiasm than survival instinct. I’m sure he could have developed into a good detective eventually, if he had survived long enough. :sweat_smile:



Wow. Hmm. Man. So, thoughts:

  • I honestly didn’t expect my guess of 守須 to be right. Almost immediately after I typed that out and sent it off and began reading again, I thought, “Nah, it’s gotta be 紅次朗, right?”. Not sure if it’s a good thing or not I got lucky guessing, haha.
  • I kind of want to go back now and re-read all the ヴァン sections with a detailed eye, see if I can catch any weirdness coming from him (moreso than we already caught, of course).
  • I find it interesting how, in the end, エラリィ was almost completely ineffective with his detective persona. He was just too nice, maybe? I wonder if part of the novel’s aim was to act as a bit of a deconstruction of the “great detective” archetype: given all these clues, you can still be led wildly off track and deceived.
  • I wonder what 島田 wanted to float by 守須 there at the end. What was his crazy thought/one last thing he noticed?
  • From chapter 10: does anyone know who the author 島田警部 guessed is? モーリス・ルブラン? I did some searching and didn’t come up with anything satisfactory.
  • Random, but I was a little surprised to read that the initials on 千織’s ring were in Latin characters. Is that typical in Japan, anyone know?
  • Was it ever mentioned/hinted at what ルルウ remembered/went to investigate when he got killed? Was it the line 守須 was using to tie up his boat?
  • I’m conflicted on my thoughts on the epilogue. 守須 obviously didn’t get the kind of closure he was hoping for post-murder, but I can’t decide whether I thought it was reasonable to have him give the bottle to 島田。 Like, maybe if 守須 had shown an ounce of guilt or something, maybe? Was he just essentially giving up since he still couldn’t come to terms with 千織’s death, even then?
    I feel like I’m on the side of, “he shouldn’t have given the bottle”. I don’t see what that act brings to the table, especially on the last page. Felt like it was giving 島田 a last little bit of the spotlight in the end, especially considering 島田 ultimately was nothing but another red herring.

As much as I love kudos, I can’t remember if I ever speculated that they were the same. :sweat_smile: Too many theories floating around.

That’s a fun thought, haha. How would they do a movie? So fun fact: while I’ve never been formally tested, I think I’ve got a light case of prosopagnosia; nothing as severe as what the linked webpage describes, but enough that I’ve re-introduced myself to people I’ve had interviews with, couldn’t recognize coworkers of my mom who I’d seen when they went about their daily business (she was a teacher, so lots of in and out of her classroom), and have trouble keeping track of characters in movies who have similar hairstyles/clothing.

They could totally have the same character with slightly differently styled hair and different clothing, and as long as no one (i.e. my roommate, who has a super great memory for faces and voices) pointed it out, I’d never see it coming.

I remember you mentioning that the manga seemed to really be leaning on one person as the killer; I never went back to read the spoiler (of course), so who was it?

My take on this is that there’s now nobody left to care. At least, no one we get to read from the perspective of. I agree, though; the body could have had interesting consequences if they had found it earlier. I wonder if we’re supposed to accept the crime of passion + suicide as the ‘truth’ now? But then that just reminds me of エラリィ and how laser-focused he was on 青司 being alive.

Thinking about it, 青司 and 守須 are definitely parallels, in both motive and execution (even if the latter was a tactic on 守須’s part). They even both confessed to their crimes, albeit in different ways.

Seconded! This has been a ton of fun; I’ve really enjoyed reading and theorizing with you all!

Gave me chills. :open_mouth: I was sad when I read them, since I knew what was coming up… I think 守須 said エラリィ seemed to be waking up at the end, right? I really hope not…

I’ve been debating whether or not I should nominate it; figured I’d give it some time so there wouldn’t be accusations of author favoritism or anything. XD

This could’ve turned into a very different book. Is it terrible of me to say I would love to see a comedy movie made out of エラリィ trying to be a master detective? I think there would be some fun interactions between him and 島田, who I felt was the more typical detective character here.

Edit: Was adding the book to my Goodreads list, and reading the English summary it had this to say:

The Decagon House Murders is a milestone in the history of detective fiction. Published in 1987, it is credited with launching the shinhonkaku movement which restored Golden Age style plotting and fair-play clues to the Japanese mystery scene, which had been dominated by the social school of mystery for several decades. It is also said to have influenced the development of the wildly popular anime movement.

I’m intrigued as to what Japanese detective novels were like before this book (what is the “social school of mystery”?), and extremely curious what exactly it’s referring to as “the wildly popular anime movement”.


I was under the impression that he somehow had found the bottle. Otherwise, how did it magically appear in front of 守須 all of a sudden? This once again looked very much like a coincidence instead of deduction, so it felt very unsatisfying. Although I was sure 島田 would somehow have the last word when I saw he was missing from the club meeting.

I wrote this back in week 5:

Which is interesting, even if it wasn’t the real nickname, because Lupin was an intelligent gentleman thief who always managed to fool the detective who was after him.

I don’t know, but Is there even such a concept as an initial letter in Japanese? It would probably have to be the first syllable? The Latin alphabet is easier to carve, it can be a true initial, and it probably looks more modern and cool or something.

Not mentioned, but hinted that it may have been the end of the rope or something similar. Which annoys me, because that would be a huge clue which エラリィand ルルウ both should have noticed right away. Oh well.

I have that too with people I see in only specific roles at specific places, and I also sometimes have trouble telling people apart in movies if they share a similar style and I don’t know the actor. But even the fact that I couldn’t tell them apart would be a clue, and also there’s really no earthly reason why he would change hairstyles. That’s exactly the trick they use in the manga, by the way.

That was @cat, not me. And I’m not sure who they were referring to, as I never properly read the manga, I just looked at the pictures of the first volume and read some random parts here and there.


Aaah, very nice! And that allusion is also great as a double-meaning, as you pointed out.

Daaang, past eefara was good. :open_mouth:

Whoops, my bad!


I think this is basically the argument Ellery had with Carr in the beginning, and the difference, for example, between Agatha Christie and Dashiell Hammett. Raymond Chandler famously had this to say about the difference between the two styles: “Hammett took murder out of the Venetian vase and dropped it into the alley" and that he gave “murder back to the kind of people that commit it for reasons, not just to provide a corpse; and with the means at hand, not with hand-wrought dueling pistols, curare and tropical fish.”
社会派, the social school of detective fiction, is as far as I understand it, all about placing a crime in the real world and in the specific social circumstances of its time. In contrast, 本格派 is a carefully constructed whodunnit, an artificial (see isolated islands, etc) puzzle that is supposed to play fair and provide the clues for the reader to solve it if they’re paying attention, while still being deviously complicated and misleading. See here for more: Shakai Detective Fiction | Japanese Mystery Wiki | Fandom


Oooh, thanks so much for the explanation! I’ll definite be reading up on that wiki link! …I’m kind of amazed there’s a wiki specifically for Japanese mystery.


I also had the same impression as @omk3 that 島田 had somehow found the bottle with the confession from the start (I guess it washed up on the beach maybe?? I found that part really confusing though (mainly cos I’d half forgotten there even was a message in a bottle)


Surely if he’d found it, it would’ve had to have been after the decagon house burned, right? 島田 sitting on evidence of that magnitude for the whole book leads to a very different interpretation of his character…

I guess that would allay my concerns about the ending, though. 島田 already knows about the bottle, ヴァン knows he knows, and comes clean, as it were. I assume 島田 would’ve been smart enough to make a copy of everything before handing it back to the murderer.


ah sorry, think that’s probably bad phrasing from me I meant ‘the bottle with the confession from the startI’ as in the one that ヴァン threw into the sea in the prologue. I don’t think that 島田 had it from the start - think it’s a mystery at which point he got hold of it (I seem to remember one bit where him and 江南 are on one of their little investigation trips and 島田 is speaking to some little kids playing on the beach or something. Would have to reread to see if there’s any hint that’s when he got it. Otherwise I guess we’re just mean to expect that it washed up on the beach sometime between when the decagon house burned and the time of the final scene with ヴァン🤔


Ah, I see what you mean now, no worries!


I finally finished - going on a trip right as the last week happens was a terrible coincidence! I read enough to know who did it a few days ago but the last bit I didn’t get to until just now and I’ve finally caught up to the thread as well.

It heavily hinted at エラリー and I was deeply annoyed by the fact it could be him.

IIRC mystery/detective books were basically banned in the war time period so not much there, but I’ve read a fair amount of pre-war crime and a little 1960s stuff so I read @omk3 's linked wiki with interest. I gotta say 火車 is 110% a 社会派 (1990s) and 天使の傷跡 (1960s) is also 社会派. Pretty much everything pre-war that I can think of off the top of my head would be 本格派 or 変格派 which doesn’t necessarily make it 社会派. Ha, learning so much today. This site is a treasure trove though, I’m intrigued.

I really enjoyed this book, it had its weaknesses but overall I felt it delivered an interesting premise and had some great twists and turns. The continued heartbreak of ヴァン at the end was a nice touch. Comparing it to the beginning it feels like he walked in expecting to be purged of his pain via revenge, discovered during the course of events that he didn’t exactly enjoy murder, and then was finally left a bit empty by the finale. I do enjoy an unhappy murderer. :joy:


I’ve been debating whether or not I should nominate it; figured I’d give it some time so there wouldn’t be accusations of author favoritism or anything. XD

I’ve loaded 水車館の殺人 onto my ereader for later, but noticed Another(上) | L33 is by the same author. From an admittedly quick scan, it seemed easier than the 館 series, so I’ve grabbed a copy of that too :joy_cat:

I think an easier pick might be on the cards for the next round… I’d have to go and check the old poll.

Edit: turns out a bunch of books got similar numbers with 体育館の殺人 | L30 just ahead, so the next pick could be rather unpredictable