The Blurb On The Back:

The lonely, rockbound island of Tsunojima is notorious as the site of a series of bloody unsolved murders.  Some even say it’s haunted.  One thing’s for sure: it’s the perfect destination for the K- University Mystery Club’s trip.

But when the first club member turns up dead, the remaining amateur sleuths realise they will need all of their murder-mystery expertise to get off the island alive.

As the party are picked off one by one, the survivors grow desperate and paranoid, turning on each other.  Will anyone be able to untangle the murderer’s fiendish plan before it’s too late?

You can buy THE DECAGON HOUSE MURDERS by Yukito Ayatsuji from Amazon UK, Waterstone’s or Bookshop.org UK.  I earn commission on any purchases made through these links.

The Review (Cut For Spoilers):

6 months ago on the private island of Tsunijoma, Nakamura Seiji (a reclusive and wealthy architect), his wife Kazue and their two servants the Kitamuras were brutally murdered and his house, the Blue Mansion, destroyed in a fire.  The prime suspect was Seiji’s gardener, Yoshikawa, who disappeared the same day and hasn’t been seen since.

Now 7 members of K- University’s Mystery Club – Ellery, Van, Carr, Poe, Agatha, Orczy, and Leroux (honorific nicknames granted to them as senior members of the Club) – are heading to Tsunijoma where they plan to stay in the Decagon House, a 10-sided building designed by Seiji.  They will be completely cut off from the mainland for a week, relying on basic supplies and facilities as they poke around the Blue Mansion ruins to see if they can work out what really happened to the Nakamuras and Kitamuras and perhaps get inspiration for stories for the Club’s magazine.

Meanwhile Kawaminami Taka’aki (an ex-member of the Club known as Doyle), Nakamura Kōjirō (Seiji’s brother) and Morisu Kyōichi (a member of the Club who did not go on the trip) have all received letters supposedly Seiji bearing the words “My daughter Chiori was murdered by you all”.  Chiori was also a member of the Club who died accidentally from alcohol poisoning over a year earlier during a Club social event but neither Doyle nor Morisu had realised her connection to Seiji.

When Doyle discovers that the 7 Club members also received letters after they left for the Island, he’s worried that something sinister is going on.  Morisu is reluctant to assist him, feeling that it would be disrespectful to the dead, but Doyle finds help through Kōjirō’s friend Shimada who’s keen to work out the mystery.  But as the pair dig into what happened on Tsunojima Island, the 7 Club members have discovered that someone is playing a deadly game with them and as they’re picked off one-by-one the survivors put all their Mystery Club expertise into effect to work out who is responsible before he or she kills them all …

Yukito Ayatsuji’s classic detective mystery (translated into English by Ho-Ling Wong) is a fast-paced tribute to Agatha Christie’s AND THEN THERE WERE NONE that’s filled with twists and turns.  Although I enjoyed it, the large cast is disorientating at first and they’re all under-developed, the ending is a bit of a cheat because it relies on the reader not being told a key fact and I didn’t really understand the killer’s motivation. 

Ayatsuji is a highly regarded mystery writer in Japan but I was unfamiliar with his work until I read a couple of articles about him and his books in 2020 and his work has not been widely translated into English.  This is his first novel, originally published in Japan in 1987 and intended as a tribute to Agatha Christie’s AND THEN THERE WERE NONE, although the nicknames of the 7 hapless Mystery Club members are also a tribute to other classic crime and mystery writers.

The novel is divided between two plot lines – the arrival of the 7 Club members on the island and what happens to them after and evens on the mainland as Doyle tries to work out why a dead man has sent him a letter.  The way Ayatsuji jumps between the two plot lines keeps the action moving, which gives the overall story pace.  However it does take a while to get going, not helped by the fact that Ayatsuji throws all 7 Club members at the reader right away and because they’re quite thinly drawn (with the exception of Ellery, the Club’s de facto leader who likes magic tricks and is convinced he has all the answers) I had some difficulty in differentiating one from the other.  However once the murders begin and the killer’s game becomes apparent, Ayatsuji does a good job of showing how the group slowly turns on each other with petty jealousies and suspicion spilling over as Ellery pursues his theory about Seiji and is confident of uncovering the truth, no matter what.

Doyle and Shimada’s pairing is interesting (not least because Doyle is definitely the Watson in their relationship), but I would have liked more of Shimada’s character here given there’s a lot of interesting information about his family (including the fact that his brother is a policeman.  I also enjoyed how Morisu plays devil’s advocate to their investigation, pointing out that they’re raising old secrets that the dead wouldn’t want raised.

There are plenty of twists and turns within the story, which kept me both guessing and turning the pages so that it wasn’t until the end when Ayatsuji reveals the killer that I felt a bit cheated.  This is partly because Ayatsuji keeps a key bit of information back to protect the killer’s identity, but also the ending is a bit of a cheat given that it rests on the killer getting caught because (for unexplained reasons) they have decided to write a confession and put it in a sealed bottle before throwing it in the sea, only for that bottle to wash up just when they think they’ve got away with it.  This in turn raises the issue of why they have decided to target the 7 Club members because we don’t really get a lot of detail about Chiori’s death so there’s instead a strong implication that the killer is basically insane in terms of allocating blame, which isn’t as satisfying as it could be.  I have to say that I also found the way the killer did it stretched credulity a little and again, it’s all explained at the end, which made me feel a bit robbed.

Despite all this, I did enjoy the book in part because there’s a charm in reading something written in the 80s when word processors were still new and uncommon and no one had mobile phones to help get them out of sticky situations.  Mention should be made of Ho-Ling Wong’s translation, which is lively and very smooth to read.  I would really like to read more translations of Ayatsuji’s work – especially if Shimada and Doyle are recurring characters and hope that we see more Japanese writers translated and getting recognition over here.