The Decagon House Murders, by Yukito Ayatsuji

One would think that a group of mystery novel enthusiasts would know better not to take up a strange invitation to an island that has a bad reputation. One of them even references And Then There Were None by Agatha Christie on the boat ride over. But then, most of the characters in the excellent The Decagon House Murders by Yukito Ayatsuji (translated by Ho-Ling Wong) are college students who think that they’re clever enough to outwit any dangers. It isn’t long before the characters of this novel start to die off in spite of all their supposed brilliance, even as they try to figure out who’s behind an astounding number of murders.

The misdirection begins immediately in The Decagon House Murders. We’re in Japan, near the island of Kyushu, but details about the exact location are obscured. Also, everyone we meet in the first chapter is known by the name of a Golden Age mystery writer. There’s (John Dickson) Carr, Agatha (Christie), (Gaston) Leroux, and more. They’re all members of a Mystery Club at their unnamed university. In addition to devouring mysteries, they also write stories for their own mystery magazine. The idea behind their trip is to use the atmosphere of Tsunojima island—the site of a mass murder/suicide—to inspire them for their new issue, as well as put their minds to the still not-quite-solved mystery of what happened. Things seem all right for the first day, but they don’t stay that way. Within 48 hours, the first victim dies.

While one clump of protagonists runs around the strange decagonal house of the title trying to figure things out and not get murdered, an ex-member of the Mystery Club receives a letter accusing him and the rest of the Club of killing yet another member of the Mystery Club the previous year. (The members of the club now on the island encouraged the deceased girl to drink so much that she died of alcohol poisoning.) The ex-member—mostly known as Conan even though he doesn’t like it—follows a thin trail of clues to the father of the deceased girl. Conan knows something is seriously wrong on Tsunojima. Worse, he as no way of contacting his friends and doesn’t have enough information to go to the police.

The two plots run in tandem, throwing up red herrings and genuine clues alike. It’s not until near the end that I was able to confirm my suspicions about what was going. Ayatsuji follows the rules of fair play, but this is still one of the most devious mysteries I’ve ever read. The Decagon House is a brilliant story in the style of Golden Age mysteries. It definitely lives up to the hype.