Locked Room Answer

On his way to the shed to return the ladder, Atami walked beside Ibusuki as he unraveled his logic.
How the culprit created a locked room.
And who the culprit was.

"… I see."

Ibusuki said when they had returned from the shed to the main wing.

"You think I"m on to something? With my reasoning. I"m just saying the method was possible… we can"t say for certain that person is the culprit."
"… You"re terribly lacking in confidence," Ibusuki gave a light smile as she tilted her head. "Not too long ago, you were reporting, "This is the absolute truth" to me with such faith in yourself."
"Erk…"

The fact he wasn"t able to believe it precisely because it was a truth he had reached on his own was somewhat pitiful… but that"s right. It"s fine to be confident.

"If my reasoning is correct, the evidence undoubtedly remains. A piece of evidence impossible to eliminate."
"That"s right," Ibusuki bit her lip, "If the culprit really did use your trick, then it would only have been possible for one person, and the evidence is surely there. But… it isn"t the sort of thing where finding it would completely establish their guilt."
"Yes, what should we do?"
"… I guess we"ll have to bring out what isn"t there?"
"Eh?"

Atami c.o.c.ked his head, but Ibusuki made a composed smile.

"Whether your logic is right or not… you need only weed the culprit out and confirm it with your own eyes."

When Ibusuki and Atami returned to the living room, Hiyama Mitsuhiko bit on at once.

"Well, well, good grief. How long do you plan to keep us waiting? Officers. Quit brandishing the power of the state to obstruct our individual freedoms."

The panic he showed in the previous questioning session had already gone off somewhere, and he had thoroughly regained his brazen att.i.tude.
On those words, Doctor Kaneki Shinya gave a light sigh.

"Hiyama-kun, give it a rest already. When a person"s died, you should care about something beyond your own rights."

He scolded him. Showing composure befitting his old age, there was a bit of a haggard look about his face.

"We"re pulling out for the day."

Ibusuki declared clearly.

"We have to give an explanation to the press as well. We"re pulling all the officers out… though you might be called to the station for individual questioning at a later date."
"Um, please wait a second. In the end, did my father commit suicide or not?"

Hishiro Nagisa posed a sound question as the victim"s daughter. "Well, that"s the direction things have taken," Ibusuki used some convenient words of wide breadth. But it seems Nagiza obediently took it as a yes.

"… But the reporters are going to come, right? Do you think I"ll be fine?"

As Nagisa anxiously hung her head, her fiancé Koshimizu Seishirou awkwardly put a hand on her shoulder.

"It"ll be alright… if that"s how it is, do you want me to stay over tonight?"
"Yes, could you please… if it please you, Dr. Kaneki, Hiyama-san, you could stay another night as well."
"Then I think I"ll remain."

Said Kaneki.

"There are things I"ll have to deal with at the hospital… but on top of that, of the doc.u.ments the Director left in this house, many of them have a level of urgency."
"I think I"ll take you up on that offer. Driving the truck back to the main branch in Tokyo is a pain, after all. If our dear policemen are to go away, this place isn"t a bad one to stay."

When you caused such an uproar, Atami sighed internally.
But, well, if everyone was going to remain in the house, it would be most convenient…

"Well, that"s how it is, so we"ll be taking our leave here. Thank you for your time."

Ibusuki gave a deep bow, and everyone apart from Hiyama reflexively returned the motion. As Ibusuki turned to leave, the officers in the room began pulling out as well.
After exiting to the corridor, she called over to Shirahama Yayoi who had mixed in with the group.

"… Shirahama-san. Truth is, there"s one thing I want you to look into."

Once Ibusuki had conveyed her request, the young forensics investigator stuck up her thumb in consent.

Late night that day, pa.s.sed one in the morning…

The culprit behind Hishiro Kouzou"s murder was in front of the freezer.

That being the case, they didn"t enter the building. Gazing pensively at the weathered building, they walked towards the pond on the left. And leaning over, they thrust both hands inside.
Ignoring the water soaking into their sleeves, they churned up the surface.
After repeating the motion a few seconds, they retrieved a single stone from the pond. The stone was a size that fit just right in two hands. For now, they placed it by the bank of the pond.
Repeating the same motion again, they retrieved another stone from the depths.
After a few seconds went by, a wooden lit bobbed to the pond"s surface.
… And from there, letting off a ma.s.s of bubbles, a wooden crate floated up. It was the same sort of boc the concrete blocks had been in…

"So you sunk it there after all."

On the sudden voice, his shoulders shook as he threw the second stone aside. It fell right into the pond, raising a splash.
Onto him, multiple lights mercilessly beamed down.
The impact was strong on his eyes that had grown accustomed to the dark, forcing him to cover them with his arms.
And as he stood in confusion, five officers appeared from the darkness to surround him.
He slowly undid his arms to take in the silhouette shadowed by the glow.
The individual who had let out a voice was the detective of the precinct, Atami.

–

"Using stones was an appropriate decision. If you tried sinking the box as it was, it would just resurface, so you needed some sort of weight. But if you had left something conspicuous around the freezer, there was a possibility the other two who you"d brought along as witnesses would have noticed. That"s why you left some moderate-sized stones around."

Atami remained mindful of Ibusuki"s eyes behind him as he spoke to the culprit.
The culprit narrowed his eyes, returning a stare. But even as he did, his head was running full throttle to think up a way to talk himself out of the situation.
… But pressed on all sides, his path of retreat had been cut off.

Atami went into his reasoning.

"The typed suicide note put us off, and that method much too bizarre for suicide led us to believe it was murder. The lone wall that prevented us from concluding it was the locked room…

A wooden crate stuffed with a ma.s.s of concrete had been placed in the freezer… on the inside, of course… to seal off the door, and using wire to pull it from outside would be impossible. Now how troubling… so,"

Atami inhaled. And making sure the culprit didn"t make light of him, he manufactured a grin around his mouth. Though he didn"t know whether he was pulling it off or not.

"We puzzled our heads all the way to solve a single question. Why did the concrete have to be in a wood crate? They could seal up the door just fine on their own.
Right, and I… no, I mean we, reached a certain hypothesis. When the culprit exited the freezer, could the wooden crate have been empty? We asked ourselves."

As the culprit showed signs of a reb.u.t.tal, Atami held up a hand.

"No, I"ll hear your objections later.
Now then… If the wooden crate was empty, it was possible for the culprit to create a locked room. We"ve already confirmed there was enough soace to pa.s.s a thread through the cap in the door. If the wooden crate didn"t have any concrete blocks in it, the culprit could easily pull it to the door and position it…
The problem"s what comes afterwards. If the box was empty, when you and the two witnesses rushed to the scene, there was no way the door wouldn"t open up. If it was an empty wood crate, then it would move easily of a grown man pushed with all his might. Now then, how did you make the locked room…? Our attention fell on yet another thing."

Atami pointed at the freezer behind the culprit.

"Why did the crime scene have to be that freezer? Is what it was. The victim"s suicide note said he chose the same method as his wife… it contained such a plausible reason it misled us. But truth be told, that choice of murder scene was what let the trick come to be."

The culprit silently furrowed his brow. And, what forceful reasoning, he shrugged his shoulders.

"Let"s put that overly-long prelude aside. To speak from conclusions, you poured water into the box to make ice. Filling it around two thirds of the way would be just about right. It reached a weight where it wouldn"t move no matter the power exerted from the outside… the victim was last seen a little pa.s.sed two, and the body was found pa.s.sed eight. At most, you had six hours to wait for the ice to harden. On top of that, you could operate the freezer from outside, and you set it at a temperature that could kill a man, so of course water would harden.
Now where did you pour the water in from? That would be from the hole-ridden roof of the freezer. At the roof around the area of the door, there were dime-sized holes opened up. Additionally, the lid of the box was considerably old, and ridden with holes. You did the calculations, and opened two appropriately sized holes in the box beforehand. There was no need to hurry with pouring the water in, so you poured it carefully to make sure it didn"t splash around. Right, right, the reason the ladder in the shed didn"t have much dust on it was because you used it, right? When you climbed up to the roof…"

Water, the water, Ibusuki whispered to him, so Atami recalled.

"Oh, also I forgot to mention, but where could you have gotten the water?"

As he said that, Atami pointed to the right of the freezer… where Hiyama"s truck was parked.

"The faucet over there. It has a hose attached, so climbing up to the low ceiling of that freezer and pouring water wasn"t a difficult task."

The culprit"s mouth was about to open again. But Atami returned a smile of leisure.

"Then why did the police find concrete when they opened it up… you ask?
That"s easy. After the s.p.a.ce sealed up by the ice crate was freed, you switched the box out. And there was only one person capable of doing that.
After three people found the body, Nagisa-san was sent to call an ambulance, and Koshimizu-san was sent to fetch a medical kit, and one person was left alone before that wide-open freezer.
Of course, that would be you, Kaneki Shinya-san."

His name called out, the a.s.sistant director of Yumoto General Hospital… Kaneki Shinya let out a deep sigh.
Unable to raise any objections, he nudged his bearded chin towards Atami to urge him to go on.

"… Let"s give an in-depth explanation of how you committed the crime. Last night, as you discussed things with Director Hishiro and Hiyama-san, you picked an appropriate time, and mixed sleep-inducing drugs into their drinks. As a veteran doctor, you could measure out a good amount that would just induce drowsiness without having them swoon on the spot. In his questioning, Hiyama-san said he "was simply so sleepy".
Whatever the case, having incapacitated the two to cut off the meeting, you waited sometime after Director Hishiro retired to his room, and carried him to the freezer. With the drugs in his system, it wouldn"t take much time for him to draw his last breath in that cold room you"d started cooling beforehand. When you finished your preparations and went outside, you could even lower the temperature to the minimum setting to hasten his death…"

Even as he said it, Atami was feeling sick. It was a much too cruel and inhumane way to go. Of course, there"s no way a premeditated murder would be humane.

"Now then, with the preparations for a locked room in place, you waited for Nagisa-san and the others to wait, and your plan to enter its final stage. While you said you went to wake Hiyama-san, you had no intent to do so. Nagisa-san and Koshimizu-san were the perfect pair of witnesses. If you only brought one, they might be suspected as an accomplice or bring about some other disadvantages, and if you had three, it would be difficult to drive everyone away.
You led the two to the cold room, had Koshimizu-san retrieve and axe, and had him break down the door. Is that because it would be harder to direct suspicion at you if you had no part in the destruction of the locked room? Of course, you had Koshimizu-san test out the door as well and if there was no one to test out the locked room you went out of your way to make, there wouldn"t be much of a point…"

Kaneki"s mouth moved slightly as he muttered something. "That"s right," Atami read from you lips.

"… I"ll go on. After the locked room was open, you made sure the other two didn"t mistakenly open the box as you took Hishiro-san out one way or another. You gave them various orders to drive them away… as an elder, and a.s.sistant director of the hospital they worked, you were in a position to order them around. It was a method only you could have used.
From there, you started acting with haste. You the rollers hidden perhaps under Hiyama-san"s truck to move the box of ice, and discard it in the pond. From its density, the box would usually float, so you weighted it down. And again you used the rollers to move the box of concrete you hid in the loading tray of Hiyama-san"s car to the cold room. The truck"s loading tray was doored off, so there was no danger of anyone noticing, and even if the truck was locked, you could take the key while Hiyama-san was asleep. If you got rid of the rollers in the pond, perhaps it would have been perfect, but when Koshimizu-san returned, you frantically rolled them away under the truck, perhaps.
By the way, you probably hid the concrete box in the shed the previous day.
I forgot to say it, but there"s another thing about the box of concrete. There was no need to pour water into the box eventually left at the scene, so it didn"t have to be ridden with holes… the reason you did it was because you feared the other two would notice the difference when they came around later. Well, that became your undoing, as it led to the discovery of the trick. Did you open up a few holes in the box itself to misdirect us from the water pouring trick? If they were small holes one wouldn"t notice unless they stared at them, the difference would go unnoticed."

Atami finally finished his long-winded speech, shutting his mouth tight as he looked at Kaneki.
The middle-aged doctor let out a long sigh, as he slowly shook his head.

"That"s right. I have nothing to add. Worse comes to worst, I thought I could talk my way out of it even if the second box was found, but… when you"ve found me here disposing of it, you see… that"s right, I killed Hishiro Kouzou."

When Kaneki admitted it, Ibusuki who"d stayed silent to that point opened her mouth.

"… There was another clear piece of evidence as well."
"Oh?" said Kaneki. "And what would that be?"
"The cups you used to drug Director Hishiro and Hiyama-san last night. They were just left lying around in the receptions room, so we had our forensics look into them. We a.n.a.lyzed their composition, and the saliva left on the rim. When we did, we found a reaction from the two cups you didn"t use."
"H-haha."

Kaneki gave a powerless laugh. Well you"ve got me there, as if to say. A laugh that even felt refreshing.

"How could this be, what a slip up. Right, right, I"m sure the thought to go back and cleanup had occurred to me, but I ended up forgetting… I guess I"m getting old."
"Did you do it because of the director"s illegal activity?"

Atami sounded convinced, but Kaneki shook his head to the side.

"That"s not it. I"m not righteous enough to kill a man for justice. The reason I killed him was a more personal one… it was for Emi-san."
"Emi-san?" Ibusuki parroted the words. "You mean Nagisa-san"s mother?"

Kaneki nodded. His face- that was beginning to show its age- warped sorrowfully.

"From the moment I entered Yumoto General Hospital as an inturn, I had fallen for her. While being the daughter of the director at the time, she was a nurse. But a few years later, she was married to Hishiro who was five years my elder. It would be a discourtesy to Emi-san so I kept silent, but Hishiro clearly married her for the seat of director. Dripping with lingering affection, I"ve finally made it to this age a bachelor."

Kaneki shrugged his shoulders in self-derision. From there, his face took on colors of hatred.

"For close to twenty years, I watched over those two as a friend. They were blessed with a splendid daughter in Nagisa-san, and it looked to me they were getting along well enough. So I got around to thinking things turned out fine this way. But… three years ago, Emi-san died.
I was struck by sorrow. Though it didn"t look like Hishiro was.
Three years went by, and just when I thought I had gotten over my sorrows, I heard the rumors of Hishiro"s misconduct. Truth be told, I brought up the subject with him at once, and he made the face of the devil… "Quiet down. We don"t want another Emi", he said. You know what that means?"

Atami thought a moment. And he shuddered.

"It couldn"t be… Director Hishiro murdered Emi-san?"

"That"s right," Kaneki wrung out a voice shaking with anger.
"Quitting as a nurse when she was pregnant with Nagisa-san, Emi-san was rea.s.signed to general affairs. Three years ago, when she had become head of the section, she noticed Hishiro Kouzou"s misdoings. And that night, she rebuked him. "If you don"t stop illegally importing medicine and falsifying reports, I"ll announce it to the world", she said. Hishiro tried to silence her with violence, but as luck would have it, she hit her head on the corner of the desk.
But that foul man… while she still drew breath, he discarded her off the balcony! And she froze to death."
"That can"t…"

Atami couldn"t help but open his mouth. What cruelty.

"Director Hishiro told you that much?"

Ibusuki kept her composure throughout. Kaneki gave a quiet nod.

"The incident was a problem of the hospital as a whole. Exposing his misdeeds would mean social suicide as his a.s.sistant director. So perhaps he convinced himself I wouldn"t say a thing. Oblivious of my affection for Emi-san…"

And Kaneki sent Atami a worn out smile.

"Right, right, there was just one thing wrong wire your reasoning. The note didn"t say, "The same way as Emi-san" to mislead you or anything. I really wanted him to die the same way as she, and I had planned to freeze him from the start. And as I was thinking over it, I thought up the trick. It was the locked room that was tacked on as a postscript."

Once he had finished saying anything, Kaneki was taken off in a patrol car, led to the detention center once protocol was filled out. Ibusuki and Atami headed for the precinct"s parking lot to make their way home.
From the interrogation room on the second floor, they headed to the parking lot in the bas.e.m.e.nt. Night had gone by, and it was practically dawn.

"We have to prepare to unmask Hiyama Mitsuhiko as well. Though that"s not our section"s job…"

While waiting for the elevator, Ibusuki spoke. Yeah, you"re right, Atami replied.

"I"m worried for Nagisa-san, who"s been left behind, but… well, despite his appearance, that man called Koshimizu seems to have some backbone, so I"m sure they"ll be fine."
"Yeah, you"re right."

He ended up repeating himself. It"s not like he wasn"t moved, but Ibusuki had already said all the words he wanted to say.

“But Atami… to be honest, I’ve gotten a better opinion of you. Truth be told, I was beginning to suspect these bursts of logic you’ve come about these days were coming from someone else entirely. Right, for example… Kirishima Chizuru.”

Atami jerked his back straight. The elevator arrived.

“N-no way. Something like that’s…”
“Yeah, it was a stupid notion.”

Ibusuki easily denied her own opinion. No, perhaps her reasoning was the borrowed one, and it wasn’t an opinion of her own. Atami suspected as such.

“… The truth is, Chief Detective Kirishima suggested it.”

As I thought. Learning that such a big-shot had his eye on him, Atami could feel a cold sweat trickle down his back.

“I-is that so. Well now, hahaha, that’s quite something.”
“Right. I’m going to cleanly wipe that matter from my memory. You haven’t gotten in contact with a single soul since the start of this case, after all… though that kid’s appearance along the way was a surprise, he didn’t show any strange behavior.”
“R-right. Ahaha.”

So he was being watched.
If he established contact with Chizuru, he really would have been in danger.

Once they exited into the lot, the two of them split. Their cars were parked in opposite directions.
Good work out there, he said in parting before getting into his car and taking a deep sigh.
But his phone suddenly shook, causing him to stir.

"W-who is it at this hour…?"

Opening the mail, he found it was something from Kirishima Chizuru. Atami opened his eyes wide. The contents were as follows.

"Atami-san,
Good work. This mail was sent using the timer function. Right now, I"m in a land of dreams.
I think the case has been solved right about now. I"m happy you were able to do it with your own power.
Ah, but if you still don"t have any evidence, and you haven"t caught the culprit, try sifting through the pond next to the freezer. You"ll find something nice.
Kirishima Chizuru."

Atami read it over a second time. And he rushed into a third.

"Eh? What…? How in the…?"

Which means he saw through the trick just from what he had heard from Shirahama?
And he had tempted Atami into solving the case on his own?
Come to think of it, Chizuru pointed out the rollers. And why did the crime scene have to be a freezer? He pointed that out as well.
No, no, that couldn"t be.
… No, it probably was.
Atami leaned back into his car seat, letting out his greatest sigh of the day. Kirishima Chizuru. Just what was he, anyways? It was almost as if he could peer into a human"s heart, that young detective…
Atami felt a chill.