The Decagon House Murders Read online

  Dedicated to all of my esteemed predecessors

  CONTENTS

  Title Page

  Dedication

  Prologue

  1: The First Day on the Island

  2: The First Day on the Mainland

  3: The Second Day on the Island

  4: The Second Day on the Mainland

  5: The Third Day on the Island

  6: The Third Day on the Mainland

  7: The Fourth Day on the Island

  8: The Fourth Day on the Mainland

  9: The Fifth Day

  10: The Sixth Day

  11: The Seventh Day

  12: The Eighth Day

  Epilogue

  About the Author

  About the Publisher

  Copyright

  All names in the text of this work are given in Japanese order, family name preceding given name.

  PROLOGUE

  The sea at night. A time of peace.

  The muffled sound of the waves welled up from the endless shadows, only to disappear again.

  He sat down on the cold concrete of the breakwater and faced the deep darkness, his body veiled by the white vapour of his breath.

  He had been suffering for months. He had been brooding for weeks. He had been thinking about just one thing for days. And now his mind was focusing on one single, clearly defined goal.

  Everything had been planned.

  Preparations were almost complete.

  All he needed to do now was to wait for them to walk into the trap.

  He knew his plan was far from perfect, but he’d never intended to plan everything in perfect detail in the first place.

  No matter how hard he tries, no matter what he might think, Man will always be mere man, and never a god.

  And how could anyone who was not a god predict the future, shaped as it was by human psychology, human behaviour and pure chance?

  Even if the world were viewed as a chessboard, and every person on it a chess piece, there would still be a limit as to how far future moves could be predicted. The most meticulous plan, plotted to the last detail, could still go wrong sometime, somewhere, somehow. Reality is full of too many coincidences and decisions taken on a whim for even the craftiest scheme to succeed exactly as planned.

  The best plan was not one that limited your own moves, but a flexible one that could adapt to circumstances: that was the conclusion he had come to.

  He could not allow himself to be constrained.

  It was not the plot that was vital, but the framework. A framework in which it was always possible to make the best choice, depending on the circumstances at the time.

  Whether he could pull it off depended on his own intellect, quick thinking and, most of all, luck.

  I know Man will never become a god.

  But, in a way, he was undoubtedly about to take on that role.

  Judgement. Yes, judgement.

  In the name of revenge, he was going to pronounce judgement on them—on all of them.

  Judgement outside the court of law.

  He was not a god and so could never be forgiven for what he was about to do—he was completely conscious of that fact. The act would be called a “crime” by his fellow men and, if found out, he himself would be judged according to the law.

  Nevertheless, the conventional approach would never have satisfied his emotions. Emotions? No, nothing as shallow as that. Absolutely not. This was not just some powerful feeling within him. It was the cry of his soul, his last tie to life, his reason for living.

  The sea at night. A time of peace.

  No flickering of the stars, no light of the ships offshore could disturb the darkness into which he gazed. He contemplated his plan once again.

  Preparations were almost finished. Soon they, his sinful prey, would walk into his trap. A trap consisting of ten equal sides and interior angles.

  They would arrive there suspecting nothing. Without any hesitation or fear they would walk into the decagonal trap, where they would be sentenced.

  What would await them there was, of course, death. It was the obvious punishment for all of them.

  And no simple death. Blowing them all up in one go would have been infinitely easier and more certain, but he would not choose that route.

  He had to kill them in order, one by one. Precisely like that story written by the famous British writer—slowly, one after the other. He would show them. The suffering, the sadness, the pain and terror of death.

  Perhaps he had become mentally unstable. He himself would have been the first to admit to that.

  I know—no matter how I try to justify it, what I am planning to do is not sane.

  He slowly shook his head at the pitch-black, roiling sea.

  His hand, thrust into his coat pocket, touched something hard. He grabbed the object and took it out, holding it in front of his eyes.

  It was a small, transparent bottle of green glass.

  It was sealed off securely with a stopper, and bottled inside was all he had managed to gather from inside his heart: what people like to call “conscience”. A few folded sheets of paper, sealed. On it he had printed in small letters the plan he was about to execute. It had no addressee. It was a letter of confession.

  I know Man will never become a god.

  And precisely because he understood that, he did not want to leave the final judgement to a human to make. It didn’t matter where the bottle ended up. He just wanted to pose the question to the sea—the source of all life—whether, ultimately, he was right or not.

  The wind blew harder.

  A sharp coldness shot down his spine and his whole body shivered.

  He threw the bottle into the darkness.

  ONE

  The First Day on the Island

  1

  “I’m afraid this will turn into the same old stale discussion,” said Ellery.

  He was a handsome young man, tall and lean.

  “In my opinion, mystery fiction is, at its core, a kind of intellectual puzzle. An exciting game of reasoning in the form of a novel. A game between the reader and the great detective, or the reader and the author. Nothing more or less than that.

  “So enough gritty social realism please. A female office worker is murdered in a one-bedroom apartment and, after wearing out the soles of his shoes through a painstaking investigation, the police detective finally arrests the victim’s boss, who turns out to be her illicit lover. No more of that! No more of the corruption and secret dealings of the political world, no more tragedies brought forth by the stress of modern society and suchlike. What mystery novels need are—some might call me old-fashioned—a great detective, a mansion, a shady cast of residents, bloody murders, impossible crimes and never-before-seen tricks played by the murderer. Call it my castle in the sky, but I’m happy as long as I can enjoy such a world. But always in an intellectual manner.”

  They were on a fishing boat reeking of oil, surrounded by the peaceful waves of the sea. The engine was making worrying sounds, as if it were trying too hard.

  “Well, personally, I think that stinks.”

  Carr, leaning against the boat rail, scowled, and stuck out his long, freshly shaven chin.

  “Honestly, you and your ‘in an intellectual manner’, Ellery. Fair enough if you consider mystery fiction a game, but I can’t stand you emphasizing that ‘intellectual’ every single tim
e.”

  “That’s surprising coming from you.”

  “It’s just elitism. Not every reader is as oh-so-smart as you.”

  “That’s so true,” said Ellery with a poker face, “and it’s very regrettable. I realize it all too well simply by walking around the campus. Not even all the members of our club are what you might call intelligent. There are one or two of them who might even be intellectually challenged.”

  “Are you trying to pick a fight?”

  “I wouldn’t dare.”

  Ellery shrugged, and went on.

  “Nobody said you were one of them. What I mean by ‘intelligent’ is having a certain attitude towards the game. It’s not just about being smart or stupid. On that measure, there’s no one on the face of the earth who doesn’t possess at least a modicum of intelligence. Similarly, there’s no one on the face of the earth who doesn’t enjoy games. What I’m talking about is an ability to play while maintaining an intellectual approach.”

  Carr snorted and turned his head away. A faintly mocking smile appeared on Ellery’s face as he turned towards the boy with the youthful features and round glasses standing next to him.

  “And furthermore, Leroux, detective fiction evolved based on its own set of rules, and if we consider it to be its own unique universe, in the form of an intellectual game, then we must admit that in these modern times, the foundations of that universe have been severely weakened.”

  Leroux looked doubtful. Ellery continued:

  “It’s a great problem for modern crime writers. Diligent police officers performing their jobs slowly but surely; solid, efficiently run organizations; the latest techniques in forensic investigation: the police can no longer be regarded as incompetent. They are almost too competent. Realistically, there’s no place any more for the exploits of the great detectives of yore, with their little grey cells as their only weapon. Mr Holmes would be a laughing stock if he turned up in one of our modern cities.”

  “I think that might be an exaggeration. A modern Holmes, fit for our modern times, will surely appear.”

  “You’re right, of course. He’ll make his entrance as a master of the latest techniques in forensic pathology and science. And he’ll explain it all to poor dear Watson, using complex specialist jargon and formulas that no reader will ever even begin to comprehend. Elementary, my dear Watson, were you not even aware of that?”

  With his hands inside the pockets of his beige raincoat, Ellery shrugged again.

  “I’m just taking the argument to the extreme, you understand. But it illustrates my point perfectly. I don’t feel at all like applauding the victory of the unromantic police techniques over the magnificent logic of the great detectives of the Golden Age. Still, any author who wishes to write a detective story these days is bound to come up against this problem.

  “And the simplest way round it—or rather let’s say the most effective—is the ‘chalet in the snowstorm’ method of establishing a sealed environment.”

  “I see.” Leroux nodded and tried to look serious. “So what you mean is that of all the methods used in classic detective fiction, the ‘chalet in the snowstorm’ is the one best suited for modern times.”

  It was late March, almost spring, but the wind blowing across the sea was still cold.

  On the S— Peninsula on the east coast of the Ōita Prefecture in Kyūshū lay J— Cape. The boat had left the rustic S— Town harbour nearby, and was moving out to sea, leaving behind only its wake and the sight of the cape disappearing below the horizon. Its destination was a small island about five kilometres off the cape.

  It was a clear day, but because of the dust storms so typical of spring in the region, the sky was more white than blue. The sunlight shining down turned the rippling waves to silver. The island lay ahead of them, wrapped in a misty veil of dust carried on the wind from the mainland.

  “I don’t see any other boats here.”

  The large man, who had been smoking silently while leaning on the boat rail opposite Ellery and the others, suddenly spoke. He had long, unkempt hair and a rough beard covered the lower half of his face. It was Poe.

  “The tide on the other side of the island’s too dangerous, so everyone avoids it,” replied the elderly but energetic fisherman. “The fishing spots round here are more to the south, ya see, so ya won’ see any boats goin’ in the direction of the island, even those that’ve just left the ’arbour. By the way, y’all are really strange college students, aren’t ya?”

  “Do we really seem that strange?”

  “Well, for one thing, y’all have strange names. I just heard ya use odd names like Lulu and Elroy and such.”

  “Yes, well, they’re sort of nicknames.”

  “Do kids at universities all’ve these kinds of nicknames nowadays?”

  “No, it’s not like that.”

  “So ya really are an odd bunch, eh?”

  The two young women, in front of the fisherman and Poe, were sitting on a long wooden box set in the centre of the boat, which served as a makeshift bench. Including the fisherman’s son, who was steering the rudder in the back, the boat held eight people.

  The six passengers besides the fisherman and his son were all students of K— University of O— City in the Ōita Prefecture and also members of the university’s Mystery Club. “Ellery”, “Carr” and “Leroux” were—as “Poe” had said—something like nicknames.

  Needless to say, the names were derived from the American, British and French mystery writers they all respected so much: Ellery Queen, John Dickson Carr, Gaston Leroux and Edgar Allan Poe. The two women were called “Agatha” and “Orczy”, the full original names being, of course, Agatha Christie, the Queen of Crime, and Baroness Orczy, known for The Old Man in the Corner.

  “Look o’er there. Ya can see the building on Tsunojima now,” the fisherman yelled out loudly. The six youngsters all turned to look at the island that was coming closer and closer.

  Sheer cliffs rose from the sea, covered at the top by a dark fringe of vegetation. The island had three capes, or “horns”, which had earned it the name of Tsunojima, or “Horn Island”.

  Because there were cliffs on all sides of the island, the boat could only make land via a small inlet, which was why the island was only occasionally visited by curious amateur fishermen. About twenty years ago, someone had moved there and constructed a strange building called the Blue Mansion, but now it was completely uninhabited.

  “What’s that on top of the cliff?” asked Agatha, getting up from the bench. She squinted her eyes in delight as she held one hand on her long, wavy hair dancing in the wind.

  “That’s the annex building that survived the fire. Heard the main mansion burned down to the ground completely,” the fisherman shouted over the noise of the motor.

  “So that’s the ‘Decagon House’, eh, grandpa?” Ellery asked the fisherman. “Have you ever been on the island?”

  “I’ve gone into the inlet a few times, to avoid the wind, but I’ve never set foot on the island itself. Haven’t even come anywhere close to it since the incident. Y’all better be careful, too.”

  “Careful about what?” asked Agatha, turning round.

  The fisherman lowered his voice.

  “They say it appears on the island.”

  Agatha and Ellery gave each other a quick look, both puzzled by the answer.

  “A ghost. Ya know, the ghost of the man who got murdered. Nakamura something.”

  The fisherman’s dark, wrinkled face creased into a frown, then he grinned devilishly.

  “I heard ya can see a white figure on the cliff o’er there if ya pass by here on a rainy day. ’Tis the ghost of that Nakamura guy, trying to lure ya there by wavin’ his hands at ya. There’re other stories too, like people havin’ seen a light at the abandoned annex, or will-o’-the
-wisps floatin’ near the burnt-down mansion, or even one ’bout a boat with fishermen being sunk by the ghost.”

  “It’s no good, grandpa.” Ellery chuckled. “No use trying to scare us with those stories. We’ll just get even more excited.”

  The only person among the six students who seemed to have been scared, even a little, was Orczy, who was still sitting on the wooden box. Agatha didn’t seem at all perturbed—quite the contrary. “That’s so awesome,” she muttered to herself in delight. She turned towards the back of the boat.

  “Hey, are those stories really true?” she excitedly asked the fisherman’s son—still a boy—who was holding the rudder.

  “All lies.” He shot a glance at Agatha’s face, then, looking quickly away as if dazzled, said gruffly: “I heard the rumours, but I’ve never seen a ghost myself.”

  “Not even once?” said Agatha, disappointed. But then she smiled mischievously. “Still, it wouldn’t be all that strange if there were a ghost,” she said. “Not after what happened there.”

  It was 11 o’clock in the morning of Wednesday, 26th March 1986.

  2

  The inlet was located on the west coast of the island.

  It was flanked on both sides by steep cliffs. To the right, facing the inlet, was a dangerous-looking bare rock surface and this cliff wall, almost twenty metres high, continued towards the southern coast of the island. On the east side of the island, where the currents were very strong, the cliff wall even reached fifty metres in height. Directly in front of them was a steep incline, almost another cliff wall, with narrow stone steps crawling up it in a zigzag pattern. Dark green shrubs clung to the face here and there. (See Figure 1.)

  The boat slowly entered the inlet.

  The waves inside were not as fierce as those out at sea. The colour of the water was also different: an intense, dark green.

  To their left inside the inlet there was a wooden pier; further back, a decrepit, shabby boathouse came into view.