The Decagon House Murders

One sentence synopsis... Members of a university detective club visit a deserted island which was the site of a quadruple murder-suicide the year before and start being picked off one by one.

Read it if you like... Agatha Christie: the book is loosely based on ‘And Then There Were None'. Fair play detective stories: the answers are there all along if you're paying attention, no stupid twists at the last minute to reveal disappointing murderers. Or cult-classic Japanese mystery fiction: the characters are one dimensional, the writing is sparse, and it's all completely intentional. The book belongs in the shin honkaku genre of Japanese mysteries, a genre defined by the reader's ability to plausibly solve it.

Dream casting... Will Sharpe as Ellery and Yōsuke Kubozuka as Shimada.

Written as kind of an homage to Agatha Christie's And There Were None, this is a similar kind of island murder mystery that was quite interesting and engaging throughout. I found the translation also to be quite well done, and finished the book in just a few hours. It's a well crafted mystery, with many similarities to the original but also it's own unique qualities. I also thoroughly enjoyed the concept of all the characters belonging to a Mystery Club and each having a nickname based on a famous crime fiction writer. Some of the characters did come off as peculiar, maybe even insufferable, but I was really not trying to connect to them much - I was only invested in what was gonna happen. And I definitely didn't see the culprit coming.

I don't read a lot of books in this genre, so I'm glad I picked a good one which entertained me for a few hours. If you are a fan of the original novel too, maybe you can give this a try - I feel you'll love it too.

This was a really, really fun ride, although one that I think not everyone would appreciate equally. I'd give this about 4 stars. If you treat this as a literary puzzle, rather than an actual story, you might enjoy this. I found the foreword by Shimada Soji to be particularly enlightening on that score, about the history behind this Japanese subgenre of cozy mysteries, inspired by the golden age authors like Agatha Christie, but also giving it a very unique twist of their own.

In fact, Shimada in the foreword touches upon what could be a point of criticism for most readers. Ayatsuji's characters in this book are not meant to be regarded as human beings but rather as pawns or pieces of the puzzle. They feel, think, and say things only as much as it gives you, the reader, hints and clues to the solution of the mystery. Don't go into this one expecting the clinking of champagne glasses or any kind of social commentary that so many golden age authors added alongside their mysteries. Ayatsuji, and perhaps the whole genre of Japanese cozy mysteries in itself as Shimada posits, is only interested in this puzzle in a vacuum, so his characters may act almost “robotically”, to quote Shimada.

The plot in itself is pretty simple. A group of students from K—University's Mystery Club head to an abandoned island for a week-long camping trip. The island was home to a reclusive architect, his wife, and some employees until they had all perished in an unsolved mass killing 6 months before the novel begins, so the Mystery Club students are keen to find some inspiration there to write detective fiction. They take up residence in the Decagon House, an annex to the main Blue Mansion of the island, both of which had been designed and built by the deceased architect. Soon, the students find themselves also victims of mass killing plot, as they are picked off one by one by an unknown murderer apparently in their midst.

I think I managed to appreciate this book a lot more having grown up with many Japanese franchises which were no doubt influenced by this burgeoning mystery genre (Ayatsuji wrote this book in the mid 1980s and I grew up in the 90s). One that came to mind frequently was The Kindaichi Case Files, a manga series that spun off several adaptations - I grew up with the live-action adaptation. In fact, the characteristic way the live-action drama unveiled its murders and solution was how I visualized the plot of this book unfolding, so similar was the vibe and presentation. Other Japanese franchises that could probably draw some parallels are Galileo, Mr Brain, Liar Game, Death Note, and so on. It was with that frame of reference in mind that I felt that I could properly appreciate this book despite the “robotic” characters and sometimes fantastical behaviour.

Another reason for the “robotic” characters could be also lie in the limitations of translation. As someone who is bilingual in Mandarin and English, I can attest that a lot of nuances and tones are completely misinterpreted or eliminated completely when translation happens. Having also studied the Japanese language for a few years before, while I wouldn't boast of any degree of fluency in it, I think I appreciated enough to know that some sentences may sound perfectly fine in Japanese but sound uncommonly stilted and stiff in English. I also think that some clues the author had dropped may have been woven in to the language of writing itself, and so may have been incredibly difficult to translate, while other clues that the author did not intend to give had to be revealed again because of the translation. I'm thinking particularly of (spoiler for the whole mystery) when the Prologue mentions an unknown person making preparations for the mass murders, but refers to them as “he”. We know immediately from the beginning that the culprit is male, barring any crazy twists. Although this doesn't help us that much since there are only a grand total of 2 female characters in the book, but it still does dampen the mystery just a little bit, and we aren't kept guessing about whether Agatha is going to turn out to be the murderer. I've a strong feeling that this is a limitation of translation because Japanese sentences often does away with pronouns all together, so it would've been very possible to write the Prologue without referring to this unknown third person by any gender pronoun at all. This is just my guess though, not having seen the Japanese version of this book.

The book was overall super enjoyable for me. I took up the invitation of trying to solve the mystery along with the characters and kept up a log of who I was suspecting most (my suspicions throughout the book: I had a fleeting suspicion of Van at first because he was the only one who had been on the island before everyone else, but somehow I was more distracted by Poe and Ellery. I was convinced that they were the Murderer and Detective, although I couldn't figure out which was which. I was inclined to think Poe was the Murderer, considering that he was always on hand with each murder and had alone time with each corpse, and thought it was rather suspicious when he didn't let Agatha see Orczy's body. Oh well, how I was mistaken.). It felt like a cozy puzzle to tease apart, and like most cozy mysteries I didn't take the plot too seriously, in that how people can somewhat continue functioning and not finding ways to get off the island even when people around them are getting murdered. There was probably some clear inspiration by Agatha Christie's And Then There Were None here, but I don't think reading that one would dampen your enjoyment of this one.

Overall, definitely recommended for cozy mystery fans or those interested in Japanese mysteries.

I really enjoyed this one, from the pacing to the atmosphere to the characters. I was worried that this was going to hew too closely to the And Then There Were None formula, but was delighted that it simultaneously did and did not. It's great when in hindsight you can see the clues you noticed and the ones you did not. The great shame was finding out that this book is part of a series with ten others...only one of which has been translated, though a second one is coming out in May.

Fast Read

It wasn't boring, though the translation seemed wooden at times. Lots of explaining and talking at length about possible suspects and outcomes, but some of the reasoning is just too improbably specific. So it was interesting, enough and, moreso, a fascinating bit of Japanese literary history.

This was delightfully twisty, but also tragic and somewhat grisly. I've made an important discovery in the continual fine-tuning of my mystery tastes: I really do prefer a detective-led story. A cat and mouse game between reader and author (POV: culprit) rather than investigator v. crime still leaves you with a puzzle to solve, but experience suggests they are often darker, sadder, without the champion for truth playing a feature role. Not my vibe, but that doesn't mean it wasn't objectively engaging.