Where the Caged Bird Roosts

The moonlight was dim, which made the meteors blaze all the more brilliantly. The Albatross could not help stopping in her tracks, bathing in that magnificent rain of light. The Peacock lifted her head to stare at the sky. "It's beautiful," she murmured. "Too bad this isn't the moment to make a wish." The Bat frowned and urged them on. "Hurry up. If we don't get back soon, people will start to suspect something." The Ostrich stood behind them without a word, clumsily holding the corpse by the feet, crying soundlessly inside his costume head. Cool wind rolled through the grass in waves. Four figures in bizarre outfits kept walking across the deserted wilderness, until the night swallowed them whole.

Two years later, at Osorezan Resort, a taxi stopped in the middle of the road beside an inn strung with colored lights. The boy inside dashed in to borrow the restroom, only to come back out and find that the driver had vanished with both the car and his luggage. "Damn it." His wallet and phone were gone too. With no other choice, Aso Makoto went back inside and begged the owner to let him stay the night. It was already late. The owner pitied the penniless young man, but the resort was packed for the tourist season and every room had been booked. "There is a big attic room upstairs with only one guest in it," he said. "He's about your age too. I'll go ask whether he'd mind sharing." Makoto thanked him over and over. A short while later he was led upstairs.

The room was spacious and tidy. Two skylights slanted through the roof, and outside, a narrow staircase led to the third-floor observation deck. A slender youth in a beige sweater was standing at the window adjusting a telescope. He turned his head slowly at the sound of footsteps, and the familiar line of his eyes and brows made Makoto stop breathing.

"You are... Izumi Shizuka?"

The summer air was hot enough to scald, yet Makoto felt as though he had been dropped into an ice cellar. The slim figure before him seemed to swell into something monstrous, every strand of hair cold with menace.

"Hello." The youth suddenly smiled. "My name is Izumi Gaku. Izumi Shizuka is my cousin. Did you know her?"

Makoto's chest jolted. Only then did he realize he had mistaken the youth for a girl. "You look so much alike."

"It's a skipped-generation resemblance," Gaku said. "Both my cousin and I take after our grandmother. We were even born on the same day. Everyone in the family used to say we were like boy-girl twins."

"I see..." Makoto forced a stiff smile. "I was one of Shizuka's fellow patients. I used to receive treatment at the sanatorium here." After a pause he looked at the expensive telescope and asked, "Did you come here for the meteor shower?"

"Yes. July and August are when the Perseids are at their most spectacular. Osorezan is a perfect viewing spot, and this place also has a history with meteorites, so astronomy lovers adore it."

Makoto seemed to relax a little. Using washing up as an excuse, he retreated into the bathroom. Once the door was shut, he checked the lock several times in a near-neurotic panic before finally turning on the shower. In the mirror his bare upper body was reflected back at him. A scar six centimeters long crossed his waist, left behind by the kidney transplant he had undergone two years earlier. Once, he and several other young patients from poor families had started learning how to wait for death before they had even properly learned how to live. Then one day the news broke that billionaire heiress Izumi Shizuka had leukemia. Her superstitious grandfather, desperate to earn merit and blessings for her, spent a fortune building a sanatorium at Osorezan and chose several patients her age, promising to cover all of their medical expenses. Makoto was selected by lottery. Together with three other lucky winners he received the most advanced treatment available and miraculously survived. Yet on the eve of surgery, Shizuka was abducted and vanished without a trace.

Half an hour later, after checking that his face betrayed nothing unusual, Makoto came back out. Inside the room, a nineteen-inch television was replaying yesterday's news: mysterious human remains had been found beside a meteor crater at Osorezan Resort, suspected at first to be the remains of extraterrestrial life. The towel slid soundlessly from Makoto's hands. Gaku was watching the screen and did not notice the terror on his face.

"Do you think aliens really exist in this world?" Gaku asked.

"Maybe," Makoto said hoarsely, swallowing hard. He was already regretting his decision to stay here.

"I'm going to visit the crater tomorrow. Want to come with me?"

Makoto shook his head at once. "S-sorry. I already have plans." Nervously he turned off the television. "It's late. We should get some sleep."

Gaku did not press the matter. He merely shrugged and slipped under the blankets. Makoto lay down in the other bed, but he slept badly. Before dawn he slipped out of the inn, crossed the woods on foot, and made his way to the Osorezan Sanatorium for the first time in years. After Shizuka disappeared, her grandfather had withdrawn his investment, and the once-comfortable sanctuary had long since fallen into ruin.

Makoto climbed in through a window and found an old birthday photograph pinned to a display board. Five people in costume surrounded the cake: the Phoenix, the Peacock, the Albatross, the Bat... Makoto's fingers brushed over each face one by one. The moment he spoke the names aloud, hurried footsteps sounded behind him. He turned and stared at the former patients from those days. "You came too?"

The four of them sat in a dusty abandoned hospital room. None of them had arranged to meet. They had simply all been summoned here by the skeleton that had surfaced in the meteor pit.

"What do we do?" asked the first to break the silence, a girl named Hayama Shion. Her nickname had been Peacock: beautiful and vain, just like the bird. "Do you think that's Izumi Shizuka?"

Across from her sat Kitajima Fumihiko, nicknamed Bat. "It's been so long. Why did her body have to come back out in a way like this?"

Kitahara Nagisa pushed up her glasses and said coolly, "I've been to the crater. It's exactly where we buried her." She had once won prizes in mathematics competitions. She would never misremember coordinates.

Makoto felt his heart sink. "Is this retribution? Does even heaven want this to come to light?"

"Don't be ridiculous." Shion bit her finger. "I've coasted on good luck all my life. There's no reason for me to go under now."

Fumihiko looked up with a flicker of hope. "Maybe the police won't identify the bones that quickly."

"They will," Nagisa said. "Even if they can't compare DNA right away, a scan of the skull will let them reconstruct her face."

Makoto instantly thought of Izumi Gaku. "Her cousin is here too. They look so alike he'll realize it immediately."

Nagisa stared. "Shizuka had a cousin?"

"A male cousin." Makoto recounted what had happened the night before and added with lingering dread, "The first time I saw him, I thought she had come back from the dead."

"You thought she was really a phoenix who could rise again from the ashes?" Fumihiko said. "Even if the police figure out it's Shizuka, they'll assume kidnappers killed her. They won't suspect us."

Makoto frowned. "But there were never any kidnappers. It was just a..."

With a creak, all four of them fell silent. Fumihiko moved to the window and peered out. Gaku was stepping through the dead branches toward the building. Staring at that face, Fumihiko lowered his voice. "That's the cousin you meant?"

They had locked the doors and windows behind them when they came in. Gaku tried the entrance, failed to open it, muttered a few words, and turned back the way he had come.

Shion watched his retreating back. "Where is he going?"

"To the crater," Makoto said, pressing his lips together. "Maybe he didn't come here for the meteor shower at all. What if he already knows something..."

"Then let's follow him and find out," Nagisa said, standing up. "I want to know what really happened back then. Aren't you curious too? How exactly did Izumi Shizuka die?"

Makoto's chest trembled. He had always wondered that himself. Had Shizuka died by accident or by murder? Even to him, the answer had never been clear. From the very beginning Shizuka had been different from the rest of them. She was a rich girl, arrogant, selfish, contemptuous of everyone. Whenever Makoto was around her, he felt like a servant in some feudal age, required to obey every whim of his mistress. They endured her pride because she held power over their lives. If she was displeased, she would threaten to tell her grandfather to withdraw the funding. Makoto was not afraid of death, but he was terrified of disappointing his family. He could not forget the look in his parents' eyes when he was given the chance at free treatment. Even Shion, whose pride was stronger than anyone's, had endured Shizuka's insults. They all wanted to survive.

Then, just at that moment, Shizuka died.

That day had been Shion's birthday. Shizuka held a costume party at the hospital, and Makoto was assigned the ostrich suit. It was midsummer. Even now he still remembered the near-suffocating misery of wearing that heavy thing in the heat. Shizuka was the Phoenix, king of birds, and the rest of them performed one ridiculous act after another like clowns flattering a queen, even while thinking only of the surgery scheduled for the next day. A famous specialist from overseas was already on the plane. If they could just endure that night, they would be reborn. But when it came time to blow out the candles, Shizuka lost her temper again, all because Makoto had blown too hard and splattered cream into her eyes. No matter how he apologized, she refused to forgive him. Phone in hand, she threatened at any second to have her grandfather cancel the operations. Makoto was nearly on his knees before her. At last Shion snapped, seized the phone from her, and hurled it downstairs.

The party broke up in bitterness. Makoto apologized miserably to the others, but no one blamed him. Instead they all felt a kind of reckless relief. In the end Makoto went back to his room, packed his things, and meant to leave for good. But when he reached the stairwell, he found Shizuka lying there in a pool of blood, her face drained of life.

Out of his mind, he called the others. Staring at Shizuka's body, one thought was born among them, though later none of them could remember who voiced it first: if Shizuka disappeared for now, no one would be able to stop tomorrow's surgeries. It was their last chance. While no one was looking, Shion and Nagisa cleaned the scene. Makoto and Fumihiko retrieved Shizuka's smashed phone and fixed it. After burying the body, they posed as kidnappers and sent messages to Shizuka's grandfather. The Izumi family, frantic to rescue the missing heiress, had no time to concern themselves with the hospital. The next day, the surgeries proceeded without a hitch.

The land between the sanatorium and the crater had once been open wasteland. Now the weeds had grown past a person's waist, and walking through them felt like sinking into a swamp. Everyone was heavy-hearted. Makoto knew that no matter how Shizuka had died, if the burial was exposed they would all be tainted by suspicion of murder.

"Police," Shion suddenly said.

Makoto looked up. Several patrol cars were parked in the woods. Blue tape kept onlookers away from the pit.

"So you came too." Gaku approached with a camera in his hand and lowered his voice. "Did you hear? That meteor crater was faked."

Makoto's heart tightened again.

Experts had already determined that the crater was nothing more than a deep hole dug with a shovel, a man-made prank that had unexpectedly turned up a skeleton.

"Was it really unexpected?" Shion murmured.

Makoto clenched his fist numbly. Two years earlier, he himself had buried Shizuka in that spot. No one else had known about it. If a meteor had truly struck there, he could have taken it for fate. But if the pit was man-made, then this was no coincidence.

Suddenly Gaku asked, "Do you remember what my cousin was wearing the day she was kidnapped?"

Makoto looked at him uneasily. "Why are you asking that?"

Gaku brought out his phone and opened several photos. "Someone secretly photographed the crater when it was first found. I paid to get copies."

At the bottom of the two-meter pit, a skeleton lay dressed in clothes. Makoto's eyes reddened at the sight. Nagisa stepped to his side. "Can I see?" Gaku handed her the phone. She studied the images over and over, then looked up with a flash of surprise, only to swallow whatever she had been about to say.

"I remember a nurse saying that the last time she saw my cousin two years ago, Shizuka was wearing a phoenix-patterned qipao and a feathered mask," Gaku said. "But afterward, when the maid packed her things, she realized a tracksuit was missing from the wardrobe. The one in the photo looks a little like it. I wondered whether these clothes might be hers. If they are, then this skeleton..."

His face paled. "Does that mean my cousin died long ago and was buried here?"

Watching his grief, Makoto suddenly felt an urge to confess everything on the spot. "Actually..."

"What kind of idiot kidnapper would do that?" Fumihiko cut in. "If it was really a kidnapping, they'd take the hostage far away. Why would they kill her here?"

"Exactly," Shion said in support. "Lots of girls own tracksuits from that brand."

Gaku looked dazed. "You all knew my cousin?"

Fumihiko said, "We were her fellow patients. In a way we should thank your family for paying to save our lives."

He smiled with lonely restraint. "Ever since my cousin disappeared, no one at home likes to mention her. It's been a long time since I heard anyone talk about her at all. I never expected she had friends here."

Makoto guiltily looked away. Then Nagisa asked in a grave voice, "In these last two years, has your family never had any news of Izumi Shizuka?"

Gaku shook his head, face darkening. "After the ransom was delivered, there was no word at all. We assumed the worst."

"Ransom?" Makoto blurted. "What ransom are you talking about?"

"On the third day after she was kidnapped, the kidnappers ordered my grandfather to tie five hundred thousand euros to a motorboat and let it drift out for them to collect."

Makoto was thunderstruck. Back then, they had only pretended to kidnap Shizuka. They had never demanded money. Who had taken the opportunity to extort the Izumi family?

Several peals of thunder rolled over the horizon. Shion said, "Looks like the weather's turning. Let's find somewhere to sit and talk."

Gaku nodded. "I'm still planning to ask at the police station. Maybe this really is connected to my cousin. If none of you are leaving, you can stay in my room."

Makoto parted from him in a daze. Barely had he taken a few steps before the rain came down in earnest, water climbing over the tops of their shoes in an instant. The mountain roads of Osorezan were steep, and in weather like this not even taxis dared go downhill. As the storm worsened, they had no choice but to take shelter at the inn Gaku had rented. The owner recognized Makoto at once and handed him a key. "Your friend called. He said that if you came back, you should go right up and not wait for him."

The moment they entered the attic room, Makoto slammed the door and glowered at the other three.

"Who did it? Who took the ransom?"

Nagisa said nothing. Light flashed across her lenses. Shion bit down on her lip. "It wasn't me."

Fumihiko, usually so stern, looked genuinely bewildered. "Was there a fifth person involved besides us?"

Makoto studied their faces uncertainly while one suspicion after another rose through him. Why had Shizuka fallen down the stairs? Who had staged the meteor crater and exposed the skeleton? Had there really been a fifth person, or had someone among them always harbored another motive?

Gaku did not return all afternoon. After eating the dinner the innkeeper sent up, Makoto drifted into a heavy sleep. Around midnight he woke to the sound of an argument. Glancing at the still-humped blankets in the next bed, he got up and went to the balcony. The rain had stopped. Through a gap in the curtain he saw Nagisa in profile, and her normally cool face was burning with anger.

"That's right. Izumi Shizuka fell down the stairs because of me!"

Makoto went cold with shock. Nagisa went on, "I only wanted to say goodbye to her. I never expected her to get so angry and quarrel with me. In the heat of it she lost her footing and fell."

Bang, bang, bang. Shion's voice came from the bathroom. "Who locked the door?"

Startled by the noise, Nagisa turned and went back up the steps. Makoto hurriedly dove into the open wardrobe beside him, clapping a hand over his mouth. The air inside was stifling. He felt his breathing growing heavier and heavier, and before long he sank back into a drugged sleep.

When he woke, there was a faint sound of someone sobbing near his ears. Dully he opened his eyes and looked toward the sofa. Shion was leaning against Gaku's shoulder, crying with red-rimmed eyes. Makoto sat up from the bed in a daze. Outside, it was already morning.

"What happened?"

Fumihiko answered him. "Nagisa is dead."

For a moment everything went black before Makoto's eyes. After a long beat he forced out, "When? How did she die?"

Gaku pushed open the skylight and gestured toward the dense stand of cedar trees in the distance. "At eight this morning a forest ranger found her body in a giant bird's nest. Cause of death was cyanide poisoning. Estimated time of death: between two and five a.m. Someone laced the inn's water supply with ether, so after dinner everyone slept very heavily. No one realized what had happened."

"I saw her," Makoto said, pressing a hand to his head. "I woke up earlier and saw her talking to someone on the balcony. She was still alive then."

"Do you remember what time it was?" Gaku asked.

Makoto turned to the electronic clock on the wall. "It showed four."

Shion wiped away her tears. "I woke up during the night too, but someone had locked me in the bathroom. I pounded on the door for ages before Fumihiko let me out. It was around four-oh-five."

Fumihiko said gloomily, "I slept hard through the first part of the night. The knocking woke me up. Half-asleep, I thought it was room service, and only then realized the bathroom door was making the sound."

"When I saw you were missing, I tried to call people," Shion said anxiously. "Your phone was off, and Nagisa had left hers in the room. We looked everywhere and couldn't find either of you. We were about to call the police when Gaku came back, smelled ether inside the wardrobe, and found you in there."

Makoto finally understood why the wardrobe had smelled so wrong. He had thought it was paint. It had been anesthetic.

As the grogginess of oversleeping slowly ebbed from his body, the memory of Nagisa whispering on the balcony rose in his mind again. Who had been talking to her then? Fumihiko had supposedly been asleep in the other bed. Shion had been shut in the bathroom. And Gaku... at what point had he returned to the inn?

"I want to see Nagisa," Shion said suddenly. "Where is her body now?"

"At the Osorezan police station for a preliminary examination," Gaku replied. "It's not far. We can go identify her."

Identify her. The words made Makoto's chest tighten in pain.

As they passed through the woods, Gaku stopped and pointed upward. "That's where the body was dumped."

Through the tangled cedar branches, against the light, a huge nest could just be made out in the canopy. A few little mountain birds chirped there in perfect peace, as if no tragedy had ever touched the place. Shion said sadly, "The albatross belongs over the ocean. Why did she have to end here?"

Makoto lowered his head in misery. The closer they came to the police station, the more he wavered. Should he tell them what he had heard on the balcony? Should he simply confess to burying the body two years ago so they could catch Nagisa's killer faster? But if he told the truth, he would never escape blame. If his parents learned what he had done just to stay alive...

"Pull yourself together and put these on," Fumihiko said suddenly, patting Makoto's shoulder and snapping him out of it.

In confusion Makoto changed into sterile clothing and followed them inside. Under the orange fluorescent lights, Nagisa lay beneath a white sheet as if she were only sleeping lightly, her face strangely calm and gentle. Shion pressed a hand over her mouth and choked back sobs. Fumihiko looked utterly defeated. Makoto stumbled backward and slid down against the wall.

Only then did it become real to him: Nagisa had been murdered. An indescribable terror took hold of his whole body, spreading through him like a sudden disease.

"Good, you're here." The medical examiner lifted one corner of the sheet and spread open Nagisa's hand. "Does anyone know what this means?"

In the center of her left palm was a shallow circular wound edged with red, clearly inflicted not long before death. At first the examiner had assumed it was a scratch from a struggle, but there were no bruises anywhere on her body, no signs that she had fought with anyone. Later the examiner found flecks of bloody skin under the nails of her right hand. Plainly, Nagisa herself had carved the mark into her palm.

"I suspect it's a dying message," the examiner said, "but I can't make sense of it."

Gaku examined the hand closely. "A circle can stand for many things. From a pictographic point of view, it could be the sun, an egg, the letter O, a numeral, a zero, or even a period. Logically speaking, it was probably meant to point to the killer's name or identity."

Makoto pushed himself upright with a hand on his knee. "Maybe... zero. She liked things related to mathematics. Just like Izumi Shizuka loved winged creatures and insisted on using birds and beasts as our nicknames, Nagisa sometimes used numbers and symbols to label the people around her. None of us ever really understood what she meant."

"In other words," Gaku said, something like excitement flickering across his face, "if we can crack this code, we'll know who killed her."

After giving statements to the officer in charge, they went back to the inn ravenous and exhausted. The owner had ordered takeout from farther down the mountain. Makoto poked listlessly at his boxed meal. Gaku sat beside him and asked, "About that zero. Do you have any clues?"

"Not really." Makoto prodded his fried egg with his chopsticks. "Nagisa once said I was like a negative number, and she was an imaginary one. And yesterday, when she saw you at the crater, I heard her whisper, 'I thought it was odd, but it turns out it's even.' I don't understand math at all. I have no idea what she meant."

"Negative number... imaginary number..." Gaku murmured. He lifted a hand to touch his own face. "Then the Phoenix really does count as even. Which would make the Ostrich and the Albatross..."

Makoto's shoulders jerked. His chopsticks clattered onto the table. "How do you know our nicknames?"

"My cousin told me," Gaku said.

Makoto watched him distrustfully. "Where were you last night? The police station is close by. Did it really take all night just to look at a skeleton?"

Gaku put down his meal. "After I left the station, I went to the sanatorium. I wanted to see the place where my cousin used to stay."

"Did you find anything?"

As he asked, Makoto realized with surprise that he no longer felt only fear. Mixed in with it now was expectation. He wanted someone to uncover the truth they had all lacked the courage to confess. But Gaku only shook his head absently and fell silent.

Makoto lost what little appetite he had left. Curled up on the sofa, he kept thinking. Before they went to the crater, Nagisa had said she wanted to know how Shizuka really died. Had that been mere theatrics? If Nagisa had caused Shizuka to fall, why say such a thing? He glanced at Fumihiko, who was smoking by the window. Thinking back, Makoto realized he had not actually seen very clearly who had been lying in the other bed that morning. If someone stuffed pillows beneath the covers, wouldn't it still look as though a person were there? Maybe the one who had spoken to Nagisa on the balcony was Fumihiko. Maybe he had locked Shion in the bathroom and put ether in the wardrobe too.

Then Makoto looked at Shion, who was sitting on the bed drinking milk. If she had really been locked in the bathroom, a simple piece of wire would have been enough to lift the latch from the inside. The banging and shouting could have been pre-recorded on a phone and used as a ringtone, set to go off when she realized he was watching.

No. That still did not fit. Nagisa died sometime after four. By four-oh-five, Fumihiko and Shion were together and watching one another. Neither should have been able to leave the inn to kill her.

Could she have killed herself out of guilt?

He clutched his head irritably and, like an ostrich, buried his tangled thoughts in his knees.

After lunch, Shion suddenly walked over and kicked Gaku's foot, then left the room. A little while later Gaku slipped on his sandals and followed her out. Watching the familiar ease between them, Makoto felt a sudden prick of unease. That morning Shion had blurted out that it was Gaku who found him in the wardrobe, but Makoto had only ever said Gaku was Shizuka's cousin. He had never once mentioned his name. How had she known it?

Makoto followed them into the corridor and went down to the third floor, searching for any sign of them, when Gaku's voice suddenly rang out behind him.

"Stop right there."

Makoto jolted so hard he tripped over his own heel and landed flat on the floor, one slipper flying off. Gaku crouched, picked it up, and examined the half-moon-shaped dent on the sole.

"Were you wearing these yesterday too?"

"Y-yes." Makoto nodded, then turned toward the half-open room beside them. Shion was standing by the bed, looking at him with an unreadable expression. The innkeeper had said every room was booked, so why were they in this one?

"Ah!"

Gaku suddenly seized Makoto by the wrist and dragged him inside. Makoto clawed at the carpet in alarm, only to see something familiar lying there: his missing duffel bag.

Gaku grabbed him by the collar and said sharply, "I need you to do one thing."

For the next few hours Makoto felt as though he had been anesthetized on an operating table, his mind gone blank. But when he went back to the attic and saw the telescope again, every nerve in his body drew tight all at once.

Kitajima Fumihiko turned and looked at the flashlight in Makoto's hand. "What's that for?"

Makoto opened the skylight and climbed down the short steps to the balcony. "The balcony light is broken. I needed to look for something, so I borrowed a flashlight."

Fumihiko followed suspiciously. "What are you looking for?"

"I suddenly remembered that when I saw Nagisa today, she dropped an earring. I don't know if it's still here. Help me look, will you? It was diamond, maybe. Or maybe not an earring but a pendant. Something white and bright."

Fumihiko frowned. "I don't remember her having the habit of wearing earrings..."

He stopped dead. His face twisted as though from an electric shock, and a faint sheen of sweat appeared on his forehead. After a long pause he lowered his voice.

"Who else have you told about this?"

"I only just thought of it," Makoto said, crouching with his back turned as if searching the floor. "I haven't told anyone yet."

Fumihiko glanced toward the iron rod propped against the wall. Slowly, carefully, he closed his hand around it.

In the night, his shadow merged with the darkness. His severe face warped into something savage. Beneath the starry sky he raised the iron rod and swung.

A flash of white cut across the dark.

Gaku appeared from nowhere and caught his wrist in midair. At the same instant Shion switched on the wall light, a camera in her hand. Makoto rolled away and scrambled to one side, then pointed at Fumihiko with grief and fury.

"So it really was you. You killed Nagisa."

Only then did Fumihiko realize he had been trapped. Even so, he kept his composure. "Don't let these two fool you. Gaku is the one who killed Nagisa. From the very beginning he wanted revenge for his cousin, and now he's trying to pin it on me."

"That motive doesn't stand up," Gaku said calmly, wrenching the iron rod away. "Because there is no such person as Izumi Gaku. Izumi Shizuka never had a male cousin. I'm just a detective Miss Hayama hired. I have no reason to avenge a stranger."

He put a finger to the edge of his hair and deftly peeled away the face he was wearing. Izumi Shizuka's features vanished, replaced as if by magic with a clean, unfamiliar young man's real face.

"My name is To Gen. Here's my card."

He offered one. When Fumihiko only stared, stunned, To Gen tucked it into his bag himself.

Shion spoke then. "Half a month ago I ran into Shizuka's grandfather at the hospital when I went back for a checkup. He was gravely ill, almost at death's door, and still he kept calling her name. I wanted to return Shizuka to him, so I secretly came to the resort and dug up her remains. That's when I found two depressions on her skull. One came from falling down the stairs. The other looked as if she'd been struck by an iron bar. I began to suspect Shizuka hadn't died by accident after all, so I hired someone to investigate. That's when we discovered that two years ago someone had extorted ransom money from the Izumi family."

Makoto stared. "Then the meteor crater was your doing too?"

To Gen nodded. "If we wanted to gather everyone together without openly harming Miss Hayama's interests, this was the best way. I disguised myself with Shizuka's face because I wanted to test the killer's reaction and draw him into the trap. The day you arrived at the resort, I had already arranged things with the taxi driver and the innkeeper so that you would meet me."

He paused. "What I didn't expect was that after seeing the photos of the skeleton, Nagisa would notice the secret written in the skull. She realized that after Shizuka fell, she had only been knocked unconscious, not killed. Someone else finished the job afterward. And because Nagisa realized that, she was silenced."

Fumihiko gave a cold laugh. "And you want to say that person was me? I have an alibi. In a gap of only five minutes, how could I possibly drag a body up into a bird's nest?"

"Was it really only five minutes?" To Gen asked. "You calculated the ether dosage in advance. While Shion was in the bathroom, you locked her in, then set the electronic clock one hour fast and arranged the bed to make it look as though someone was sleeping in it. After that, you went out to the balcony to meet Nagisa, whom you'd already arranged to see there, and deliberately let Makoto witness her confession so he would believe she was still alive at four in the morning."

"But you didn't expect Makoto to step on the telescope's recording switch when he hid in the wardrobe. It captured the meteors outside. The meteor shower ended at three fifteen. If it had really been four when Makoto saw Nagisa, how could there still have been meteors in the sky? Isn't that why you decided you had to kill him too, before he realized?"

To Gen's mouth flattened. "Of course, the timing alone doesn't prove everything. The real proof is the code Nagisa left behind."

Makoto said, "You mean that zero? It stood for the killer's name?"

"Exactly." To Gen walked to the message board on the wall and drew a set of axes with a marker, a horizontal x-axis and vertical y-axis, with zero in the middle. "Nagisa once said I was an even number. What she really meant was the Phoenix. The phoenix is not a single creature but a joined pair, male and female, one body in two forms. When Nagisa saw the face I had disguised myself with, she realized that Izumi Gaku and Izumi Shizuka were like twins: not one person, but two. That's why I was even."

"As for the negative number Makoto represents, that too comes from his nickname." To Gen marked a minus sign and a point to the left of the axis. "Negative numbers lie to the left of zero. Makoto's nickname was Ostrich. Ostriches are famous for burying their heads in the sand. If you think of the vertical axis as the ostrich's legs, then the negative point buried to the left is like its hidden head."

Makoto stood there shaken to the core. Had he really lived his whole life in exactly that posture?

"Next comes Nagisa herself. Her nickname was Albatross. Sailors used to superstitiously believe that albatrosses were the spirits of drowned companions, ghosts that brought bad luck and death. Imaginary numbers were also once treated as false, nonexistent numbers, the ghosts of real numbers. Just as sailors feared the albatross, mathematicians once recoiled from the existence of imaginary numbers."

"And finally, zero." He tapped the center of the axes. "It is neither positive nor negative, neither composite nor prime. What does that resemble most?"

Shion answered at once. "A bat."

"There's an old fable," she said, turning her mocking gaze on Fumihiko. "When the phoenix, king of birds, held a feast, the bat did not come, claiming that because it had beast's feet it belonged to the kingdom of beasts. Later, when the kirin, king of beasts, held a feast, the bat failed to appear again, claiming that because it had wings it belonged to the kingdom of birds. When the phoenix heard of this, she declared the bat a monster that was neither bird nor beast and banished it forever."

She laughed bitterly. "You were always like that. You despised Izumi Shizuka's arrogance, but you also looked down on the rest of us for being lowly and poor. You wanted to stand above poverty, yet you still coveted other people's wealth. That's why Shizuka called you Bat. You were never truly her friend, and you never truly belonged with us either. You stood on neither side. From beginning to end you cared only for yourself. So when Nagisa accidentally made Shizuka fall, you seized the chance. Pretending to help cover things up, you killed Shizuka yourself and extorted her family's money."

To Gen lifted the iron rod. "I searched the sanatorium all last night for this. I didn't expect you to kill again at a moment like this. You really are beneath even beasts."

"Neither positive nor negative. Neither bird nor beast. Ha!" Fumihiko covered his face and began to laugh, the sound horribly distorted. "So the ghost of the albatross really did come to haunt me. Two years ago I lost the place where I lived. And now I can't even keep the place where I'll be buried?"

Makoto stared at him in a daze and felt a belated chill run through him. He had buried his head all his life, thinking that if he could not see the Phoenix's fire, he would never be burned by it. In truth he had only imprisoned himself more deeply in its shadow. If he did not pull his head out of the sand now, perhaps he would never see the free night sky at all.

"I was the one who buried Izumi Shizuka's body."

He forced his chin up and swallowed back the tears flooding his eyes. Beside him, Shion bent the proud back she had always kept straight and sat down at his side. Thinking of the spoiled girl who had once thrown a birthday party for her, she said softly, "We're taking Izumi Shizuka and Kitahara Nagisa home."

To Gen looked at Kitajima Fumihiko, who seemed to have had his soul scooped out of him, and let out a silent sigh.