The Decagon House Murders: Review

The Decagon House Murders (1987) by Yukito Ayatsuji is a daring homage to the Golden Age detective novel and, most particularly, to Agatha Christie's classic impossible crime novel, And Then There Were None. It also represents a resurgence of the classic crime novel in Japan. As is stated in the notes at the end of the 2015 English translation by Ho-Ling Wong:

The publication of The Decagon House Murders in 1987 was seen as a mile stone in detective fiction and the start of the shin honkaku movement. The term...now symbolises the rebirth of the classic puzzle-plot novel with a new twist, audacity: pushing the bounds of the puzzle-plot novel while adhering to its fair-play rule.

Ayatsuji takes the familiar trope of a group of people stuck on an island with no escape from a murderer and gives it a twist. This time, unlike the Christie novel, the people aren't strangers brought together by an unknown host--they are a group of students who are all members of a mystery club at a local university. They are so immersed in their hobby that they have each taken names from classic detective fiction: Agatha, Orczy, Van Dine, Leroux, Ellery, Carr, and Poe. The island and Decagon House was the site of a ghastly murder (possibly murder-suicide) just six months before and it appeals to their sense of mystery. When the uncle of one of the club members buys the property, the club takes advantage of their connections to plan a week's excursion. They explicitly tell the fisherman who runs them out to the island on is boat not to come back for a week.*

"So I really don't have to check up on ya even once?" the fisherman asked the six as they set foot on the dangerously creaking pier. "Don' think phones work here."

Van Dine meets the six--he had come ahead to bring the supplies and prepare the lodgings and they settle down for their stay. Initially, they enjoy exploring the grounds and wondering about the details of the crime six months before. But it isn't long before they are involved in a very personal murder mystery of their own. Someone begins killing the club members--one by one. Has one of their own gone mad or is there someone unknown hidden on the island? Clues begin to point to someone connected to the previous murders. Did that killer manage to hide on the island all this time? Ayatsuji manages to produce an unexpected answer that is at once surprising and highly satisfying.

This is a highly enjoyable puzzle-plot mystery. Since it is focused on the puzzle aspect, the characterization suffers a bit, but not enough to keep mystery fans from enjoying themselves. The solution to the mystery is quite audacious and, while I kept wondering if perhaps X might be the killer, I couldn't figure out how it would be possible. The clues are there if you just know how to interpret them. The motive isn't quite as clearly given, but there are subtle hints. ★★★★



*Note to self: If I'm ever invited to a secluded island for an extended stay--even by people I think I know well--make sure somebody will be checking up on us regularly (like--every. single. day.). AND make sure I bring along an emergency pack that contains an easily portable, inflatable boat for getting off the island ASAP if a madman starts knocking off the guests.