The Decagon House Murders by Yukito Ayatsuji

Hey everybody, let’s go to the island where there was a series of horrific unsolved murders several years ago!”

And nobody from the University Mystery Club, not Carr, not Ellery, not Agatha, not Orczy, not Van Dine and not Poe thought this was a bad idea…

The seven friends (who have nicknames based on classic crime writers) decide to visit the island, staying in the so-called Decagon House due to everything in it having ten sides. But on the second morning, they come across something bizarre – seven plates labelled First Victim to Fifth Victim, Detective and Murderer. And the following morning, one of those plates is glued to a bedroom door, a bedroom that contains the dead body of one of the club.

The original killing spree was one body short of what was expected – presumably that of the killer. But if it was the killer who survived, who was that killer? And are they still on the island? Or is the killer someone else – but the only people on the island are the seven members of the Mystery Club…

Yup, it’s And Then There Were None. Sort of. Well, vaguely sort of.

Locked Room International published this a couple of years ago, and I’ve finally got round to taking a look at it. No idea why I delayed, as it’s been sitting on my Kindle for a while now. Maybe it was the Scooby-Doo-ish plot summary. Anyway, the sound you can’t hear is me kicking myself for leaving it that long. Because it’s pretty damn good. Although there isn’t really a locked room in it…

Just to say though, as you might expect from the nicknames, this is clearly aware of what it is a homage to – indeed, the original Christie tale is referenced a few times. These people have read the original book and can see the parallels. Not that it’s going to help many of them…

Unlike the original, we actually have two mysteries here – the one from the past and the one in the present which may or may not be the same mystery. And interestingly, the one from the past is investigated separately by an ex-member of the club who is blissfully unaware of what is happening on the island. The picture builds gradually until everything becomes clear.

Is it clever and different enough from And Then There Were None? Most definitely. It’s a real page-turner as well – once started, I had difficulty putting it down. I think it’s probably one of the best things that Locked Room International have published.

The book is credited with causing the popularity of the Japanese honaku school of crime-writing, which from the little I can see, just means writing classic whodunits with a bit of a modern feeling to them – hey, if only there was a blog that looked for just that sort of thing… And it’s a classic mystery, although I’m not convinced how fairly clued it is. I spotted the killer because of a slightly clumsily written paragraph and had made a reasonable guess at something else as well. The revelation at the end didn’t feel as jaw-dropping as it is clearly supposed to be.

And you have to ask why nobody in the group had ever noticed the connection between SPOILER and SPOILER? Seriously, two major deaths and nobody noticed? And the fact that what appears to be artistry concerning some elements of the murder-spree coming down to luck (or destiny) is a bit annoying.

But regardless, I couldn’t put this down and I’m sure someone who has read less detective fiction than me (i.e. most people) will be stunned by the ending. It’s an excellent translation by Ho-Ling Wong, and if it wasn’t for the cultural references, I probably wouldn’t have realised it was a translation. I may have spotted things about the mystery, but I can still appreciate a well-crafted tale. Highly Recommended.



  1. Agreed, it’s an absolute better. Though I’ll be honest, I missed the killer and was completely floored by the revelation I’m question — easily one of the best surprises of my last few years of reading in this genre


  2. I did enjoy this, and was floored by the revelation at the end, but one thing that didn’t quite work for me was the marrying of a very Golden Age sensibility with the cruel nature of some of the murders- especially the final one, which seemed to me gratuitously sadistic. Notoriously, deaths in GA mysteries are instantaneous and painless- they are simply there for the puzzle. The deaths in this book seemed to go beyond that, though not to the same extent as The Tokyo Zodiac Murders.
    There, I found the disconnect between the detectives light GA style bantering over some horrific acts of violence quite offputting.


    • Fair comment, this, but it’s the meeting of these two schools that I find so fascinating. You only need to look at early adopters like Edogawa Rampo’s The Black Lizard to see that strain of grand guignol grotesque in Japanese crime fiction, and reconciling that with the more muted affairs of GAD is where the real excitement starts for me…

      Liked by 1 person

  3. All the recent English-language Japanese mysteries by LRI have been excellent. (And I’m including the republishing of “The Tokyo Zodiac Murders” even though it wasn’t published by LRI. LRI’s John Pugmire edited it.) The puzzles are logically constructed and are worthy of comparison to Ellery Queen and other Golden Age masters. The one thing to get used to is that Japanese culture is different from the West, and Japanese characters don’t react the same way that we’d expect. But that doesn’t affect the solution to the mystery. I don’t know when LRI will follow up both “The Decagon House Murders” and “The Maoi Island Puzzle”, but I am looking forward to it.


  4. My eyes lit up when I saw this posted, since I was wondering if Japanese honkaku mysteries were on your radar. It’s too bad so few of them have been translated since I’ve really enjoyed the ones I’ve read.


  5. I very much enjoyed this title, and was disappointed that I bought a translation in Mandarin just before Ho Ling announced his translation in English. Then again, it gave me the opportunity to read it again, as I wasn’t sure I fully grasped the Mandarin version. I think the second read convinced me that it wasn’t quite a fair-play novel, even though the culprit was hinted at. But I still enjoyed it. 🙂


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