Chapter 3: Locked Room Breaking At Your Service

Having proclaimed the locked room mysteries solved, Ms. Chiyori gathered everyone in Shitsugi's cottage. To be precise, she gathered everyone except Sotodomari, Ms. Breakfast, and Mitsumura. Sotodomari declined her invitation, sitting at her bonfire and saying “I'm busy making lunch,” and Ms. Breakfast didn't come since she couldn't even speak Japanese. I didn't really know what was up with Mitsumura, but according to Ms. Hitsujiko, who was in charge of delivering her meals, she had just said “Not interested.” Speaking of Ms. Hitsujiko, I couldn't see her anywhere. She was here earlier. Where had she gone?

“Now, allow me to explain the locked room trick.”

However, Ms. Chiyori didn't seem particularly concerned and addressed those who had gathered in the cottage. Then she turned to the door.

“As we all know, when Shitsugi's body was discovered, this door was locked in two different ways: Locked with the thumb turn, and with the bolt.”

Indeed, that was how it was. A solid locked room with two different locks. Honestly, I couldn't see how it was possible.

“So then,” Poirotzaka said, “Do you mean to insinuate that the perpetrator vacated the premises via the window? But that window was...”

It was locked with a crescent lock, and the crescent lock had been secured in place with duct tape. So it seemed equally impossible to leave through the window.

“In other words, leaving via the door or window are both impossible,” Otomigawara said. “Of course, I knew about the crime already, but it's so exciting hearing it described by a detective! So, did the culprit escape through the door or window?”

“Of course,” Ms. Chiyori said, “they used the door.”

“The door!” said Otomigawara.

“After killing Mr. Shitsugi, the culprit exited via the door and locked the cottage from the outside?” Gentleman asked, clearly interested. “But how? The only key to the door was found inside the cottage. And besides, even if they could somehow get the key back into the room, that would still leave the bolt. That can only be set from inside the room, right?”

That was true. It seemed impossible to lock that door from the outside.

“No, it is possible,” Ms. Chiyori said. “It is possible to lock the door and set the bolt from outside the room. Or rather, it's possible to do both at the same time with a single trick.”

Locking the door and setting the bolt with the same trick?

“Well, it'll be faster to show you.”

Ms. Chiyori approached the door to the cottage. She picked up something that had been propped against it.

It was an L-shaped piece of wood. Its vertical bar had a length of about 1 meter. Given its rough construction, it may have been hurriedly thrown together specifically for this demonstration. Ms. Chiyori took some duct tape from her pocket and used it to affix the L-shaped piece to the bolt. When viewed from head on, the bolt was rectangular, and Ms. Chiyori affixed the piece of wood near the bottom of the rectangle – specifically, on the left edge near the bottom. Now the right tip of the L was stuck to the underside of the rectangle. As a result, the bolt had assumed the shape of Zenigata Heiji's jitte. It looked like a branch was growing out of the bolt.

“And now we're ready,” Ms. Chiyori said. Then she pulled a small walkie-talkie from her pocket.

She spoke into it.

“The preparations are complete. Please begin.”

A voice came from the walkie-talkie, saying “Understood.” It was Ms. Hitsujiko's voice. I guess when she disappeared, it was because she'd taken on the role of Ms. Chiyori's assistant. When had she gotten that position?

Yozuki let out a voice from next to me. “Wuh?” “What's wrong?” I asked. “No, it's just... Did you feel shaking just now? It might have just been my imagination.” As soon as she said that...

This time, the vibration was clear. The cottage swayed vertically, as if it was being pulled by something, and my sense of balance was suddenly thrown off. What on Earth...? I looked around in a panic. And soon, I realized what was happening.

It was leaning.

The entire cottage was being leaned over.

The floor of the cottage was starting to slope, with the south wall at the top. It wasn't a steep slope at first, but little by little, the cottage was getting more inclined. It was as though the entire cottage was being picked up by something.

As soon as I thought that, it clicked. I ran up the slope of the floor and threw open the double window at the top. Then I leaned out the window and looked outside.

It was the truck-mounted crane.

The truck-mounted crane was being used to lift the side of the cottage, tilting the whole building over.

It was almost certainly the same crane I'd seen in the garage earlier. And although I couldn't see from where I was, the crane was probably hooked to the whisked decorations on the southeastern and southwestern corners of the roof. That would allow it to be tilted over with its south side at the top, as it was now.

My feet almost slipped out from beneath me. The angle was gradually getting steeper.

“Kasumi,” I heard Ms. Chiyori's voice from behind me. “It's dangerous up there. Come down.”

When I looked back, I saw that everyone else had already moved against the north wall, the bottom of the slope. That was certainly the safest place to be. The floor's angle was already approaching 30 degrees. That was the sort of steep uphill climb bicyclists had a hard time with. I stepped back from the south window and sprinted down the slope. I joined the others against the north wall.

Stopping to listen, I could definitely make out the sound of the crane's engine.

The angled got even steeper. And just as it exceeded 40 degrees...

The bolt on the door, located on the west wall on the side of the slope, gave in to the force of gravity and violently slammed to the side.

When it did, the tip of the L-shaped piece of wood, the tip of the jitte, hit the thumb turn and rotated it.

The sound of the lock echoed in the room.

We all stared in amazement.

With the thumb turn turned, the door had been locked – and at the same time, the bolt had slid into position to block the door, completing the locked room.

The angled floor slowly returned back to its usual level state. Once we were back on solid ground, Ms. Hitsujiko, the crane driver, popped her head in the window.

“This is the trick the criminal used,” Ms. Chiyori said. “The culprit tilted the cottage on its side to slide the bolt into place. That's why Shitsugi's body was against the north wall. Either it slid there when the floor was tilted, or maybe it was placed there on purpose to make sure it wasn't damaged by the fall.”

Ms. Chiyori walked to the door of the cottage and turned her attention to the L-shaped piece of wood taped to the bolt.

“The remaining problem is how to retrieve this wood from within the locked room.”

By now, I could explain that much without needing to be told.

“It was ice, wasn't it?” I said. “They prepared an L-shaped piece of ice in the same shape as that wood and stuck it to the bolt. They affixed it with liquid nitrogen instead of tape.”

Pour water over the bolt, then place the L-shaped piece of ice against it. By pouring liquid nitrogen over it, the water on the bolt froze, causing the bolt and the L-shaped ice to freeze together. By pouring on more water, freezing it with liquid nitrogen, and repeating the process again and again, you could make it as strong as you wanted.

Then, as time passed, the L-shaped ice melted and disappeared from the locked room. Of course, the water marks would remain behind as traces. And in fact, there had been those traces left at the scene, making it clear that an ice trick had been used.

Ms. Chiyori nodded at my explanation.

“That is an impressive trick, isn't it?” Poirotzaka said in amazement. “I never thought one would tilt over the entire structure just to lock the door. Is the domicile not affixed to terra firma?”

Ms. Chiyori shook her head.

“This cottage has no running water or gas. There's no toilet, so there's no sewage, and the electricity comes from the solar panels on the roof, so there's no wires leading outside. So I didn't see anything attaching this cottage to the ground. I don't know why it was built like this, but from what I've heard, all the cottages on this island were built when the mystery novelist Richard Moore owned the island. Moore may have designed this cottage to enable this locked room trick from the beginning. Of course, I doubt he was ever planning to commit a locked room murder in real life. He may have just built this cottage because he wanted to create a building that would be compatible with a trick he'd come up with. And the culprit took advantage of that playful spirit to kill Shitsugi.”

 

 

The Living Locked Room Library knew every locked room trick in existence, including ones not yet discovered. If they were on the island, they may have been able to immediately discern Moore's intention and copy his trick.

Thinking that, I looked around the room again.

An empty room with no furniture. It was likely that the cottage hadn't been empty to begin with, but that the culprit simply took it away. With that large, floor to ceiling window on the south wall, it wouldn't be difficult to remove all the furniture from the cottage.

And all the lights in the room were embedded in the ceiling. If the lights had been on chains or something like that, it would have caused strain when the cottage was tilted over, and there was a possibility they'd come loose, but that problem didn't exist if the lights were in the ceiling.

“But,” said Dr. Iori, “It's incredible they were able to lift this cottage with a crane. I mean, a cottage is so heavy!”

“It's not so strange. An average house weighs about 40 tons,” said Gentleman. “This is only a one story cottage, so it's probably lighter than that. What is the tonnage of the crane you used to lift it just now?”

“It's a 60 ton crane, Father,” said Ms. Hitsujiko.

Ms. Chiyori nodded.

“This completes the explanation of the locked room trick used in Shitsugi's murder,” she said. “So, I will now explain the locked room trick used in Otozaki's murder.”

We went back into the mansion to hear the trick used to kill Otozaki. Ms. Chiyori gathered us in front of the door to the basement stairs, the locked door of the incident.

She began without preamble.

“The trick in this case is extremely simple. The bottom line is that the culprit used a hinge trick to lock this door.”

A hinge trick...? We all gasped. So the culprit unscrewed the door hinges, removed the door, turned the thumb turn to extend the deadbolt, then fit the door back into the frame, reapplied the screws, and thus locked the door.

But...

“That isn't possible.”

We'd been over this several times already, but when the door was closed, the screw holes weren't accessible. Therefore, the culprit couldn't have reapplied the screws and, therefore, couldn't have used this trick. That should have been the conclusion...

But when I said that,

“You're right,” Ms. Chiyori said. “It's true there's no way to perform a hinge trick unless you can tighten the screws.”

“It sounds to be like you are contradicting yourself, m'lady,” Poirotzaka said, sounding disappointed in her. “How did the culprit return the door?”

“Of course, with the hinge trick,” Ms. Chiyori said with a shrug. “It's simple. You can't reapply the screws while the door is closed because the holes are hidden. So, they just reapplied the screws while the door was open. In other words, the culprit tightened the screws after the locked room was opened.”

That was the most confusing thing yet. Tightening the screws after the locked room was opened? That made no sense. That would mean when the culprit locked the room, the hinge's screws weren't properly applied.

And of course, if the screws were affixed properly, the door wouldn't be fixed to the door frame. It wouldn't be stable – it would have fallen over at the slightest touch.

But that wasn't what had happened. Why? I got an idea.

“Did the culprit use something other than the screws to secure the hinges to the door frame? For example, a strong glue.”

 Ms. Chiyori nodded.

“Yes, the culprit secured the door with glue. After the door was opened and the body was discovered, the culprit reapplied the screws to the hinges. What lies beyond this door...” Ms. Chiyori opened the door in front of us. “It's a stairway leading down tot he basement. And the body was found in the basement at the bottom of these stairs. You can't see this door from the basement. They could easily tighten all the screws on the hinges while everyone else was preoccupied by the corpse in the basement. If they worked fast, it would have taken less than a minute.”

Indeed, from the basement where the corpse was discovered, this door was a complete blind spot. Even if the culprit had been up there re-tightening screws, there was no way we'd see them. And it was unlikely we'd all return back to the door so soon after discovering the body. If there was a dead body, we'd naturally be distracted wanting to investigate, especially if our group was made up of people from the Locked Room Trick Game.

“B-But,” Dr. Iori protested, “Isn't it not possible to use glue to secure the hinges? If the glue was strong enough to secure the door, I don't think it would be easy to remove, and it would have left a mark.”

She was right. I wondered if there was any way to overcome that hurdle. But before I could think of anything, Otomigawara let out a noise.

“Could it be, the culprit used that?”

Ms. Chiyori nodded at her.

“Yes, they did.”

That? What was that? Poirotzaka beat me to the punch.

“Could it be, you are referring to that? The adhesive sold by Otomigawara Industries that dissolves in hot water.”

I gasped. The popular product of Otomigawara Industries, that had enough adhesive strength to hold objects tens of kilograms in place but could be removed with just hot water. I'd heard it was selling well because it was useful for things like making models.

The culprit used it to temporarily secure the door. Afterwards, they re-tightened the screws and removed the adhesive with hot water.

“Ah, I see,” Yozuki exclaimed, “That's why the door hinges were wet!”

The evidence was the wetness of the hinges. I remembered the conversation I'd had with Ms. Chiyori when we investigated the locked room. At the time, I'd said “What if the liquid on the hinges was something other than water?”, and Ms. Chiyori had had a strong reaction.

Indeed, the liquid on the door wasn't just water. It was hot water.

“That is the whole locked room trick of Otozaki's murder,” said Ms. Chiyori. “And there is only one person who could have used this trick. Therefore, we can work backwards from this trick to identify the culprit.”

“Work backwards to find the culprit?”

Ms. Chiyori nodded at me.

“I'm sure you've realized this already, but just to be certain, there are some types of locked room tricks that reveal the culprit's identity as soon as they're solved. The trick Shitsuri Mitsumura used on the first day of the Locked Room Trick Game was like that. Since pulling on the trick uproots the culprit as well, I call solving cases like this 'using potato logic'.”

Like how potatoes grew together so you could pull up more than one at a time? ...Setting aside her naming sense for a moment,

“Are you saying we can use potato logic to find the culprit in this case as well?”

Ms. Chiyori nodded at me.

“As I said earlier, there's only one person who can use this trick. Therefore, that person is the culprit. Simple, isn't it? Since no one else can use the trick, they aren't the culprit.”

That certainly was simple. “But...” Yozuki tilted her head to the side.

“The trick the culprit used was just gluing the hinges on and then reapplying the screws after the locked room was opened, right? Anyone could do that.”

Ms. Chiyori grinned.

“But they couldn't. It might seem like anyone could have used this trick, but in actuality, it could only have been used by a select few. While we were distracted, the culprit reapplied the screws. Do you know what that means?”

“Huh?”

“When the corpse was discovered, the culprit tightened the screws. In other words, those who were there at the scene when the corpse was discovered can't be the culprit.”

When she said that, all of our expressions hardened. We glanced about at each other. Everyone dug through their memories to recall who was at the scene.

“Um, if I recall,” said Otomigawara. “I think almost everyone here was there. We were all in Shitsugi's cottage, and we moved to the basement as a group.”

That much was true. So, I organized my memories based on her words. So, when Shitsugi's body was discovered, who was there? I counted off the party members one by one.

“First off, I was definitely there. So was Yozuki... and Ms. Hitsujiko and Gentleman were there.” They certainly stood out. I'd probably never forget what I saw of them.

“I was present as well,” said Poirotzaka, followed by Otomigawara saying “Me too.” “Of course, I was as well,” Ms. Chiyori said proudly.

“All that's left is... Yes, Ms. Breakfast. She showed up later with the toy rabbit with the knife in its chest. That's what lead to Otozaki's body being discovered.”

So, I searched my memories once again. The remaining people were...

“Mitsumura, Sotodomari... and Dr. Iori?”

Someone among those three was the culprit.

“However, Shitsuri Mitsumura was penalized as part of the Locked Room Trick Game and is currently 'imprisoned',” Ms. Chiyori said. “And as I confirmed earlier, she never appeared on the surveillance camera recording the entrance to her prison. The windows in that room are fixed and don't open. Therefore, Shitsuri Mitsumura is not the culprit. And Sotodomari...”

“Sotodomari has an alibi,” I said.

I was the one who could provide her that alibi. Because Sotodomari had been with me the whole time from 2:00 to 4:00 last night, the same time Shitsugi and Otozaki were murdered.

Therefore, Sotodomari wasn't a suspect. In other words...

“You are the culprit.”

Ms. Chiyori pointed at her.

The island's attending physician, Iori Yamazaki, stood there with a pale face.

Iori Yamazaki, despite not having had her name said, froze in place for a while. Finally, she let out a “N-No...”

“No, I'm not the culprit-”

“I'm disappointed in you,” Otomigawara snapped. “I never thought that you could be the culprit... I'm all for locked room murders, but it would cause trouble if my own doctor were the murderer. Have you been lying to me this whole time? Unforgivable...”

Otomigawara turned to Iori with a withering glare. Dr. Iori once again said “N-No, I'm not the culprit-”

“But, is there anyone other than you who could have created this locked room, Dr. Iori?” Gentleman decided to join the discussion. “As one of the Five Archbishops of Tower of Dawn, I have witnessed the scenes of dozens of locked room murders, so I understand. This locked basement is perfect. That it was solved is nothing short of a miracle. I can see no other possible solution. Ms. Kurokawa's reasoning suggests the only possible answer – and that is why there can be no other culprit than you, Dr. Iori.”

Poirotzaka and added in an “I agree.”

“Though it wounds me to admit it, it was a brilliant deduction. I don't believe there is any other trick that can explain that locked room. Thus, inevitably, the culprit is...”

“But...” Iori looked hopeless. She looked at me with pleading eyes, but I quickly looked away. I couldn't stand being looked at like that. And I also agreed with Chiyori Kurokawa's deduction.

That was definitely the correct answer. The case had been solved.

“B-But, I don't have any motive for killing them...”

“You don't need a motive, do you?” Otomigawara taunted Dr. Iori, who shrank back. “The Living Locked Room Library is a locked room agent. In other words, an assassin. An assassin is someone who kills for money, so they don't need personal motives.”

That remark struck a critical blow, and the the room completely shifted to believing she was the culprit. “That settles it,” Ms. Chiyori announced.

“So, what do we do now, Otomigawara?”

Otomigawara was surprised to be suddenly addressed by Ms. Chiyori.

“What do we do?”

“Yes, what do we do?” Ms. Chiyori scratched her head. “About Iori. It'll be a while before the police get here. We can't just leave her alone.”

“Ah, I see. That's certainly true.” Otomigawara finally got it. “So, we should lock her up somewhere. Where would be a good place...”

“Oh, in that case,” Ms. Hitsujiko raised her hand, “We have a perfect place.”

“We do? Where?”

“The Tower of the Cross.”

When Ms. Hitsujiko said that, Otomigawara looked stunned for a moment, then her expression relaxed.

“The Tower of the Cross? Why that's perfect!”

Otomigawara was excited, but the rest of us couldn't keep up with the discussion. After we all exchanged looks, Yozuki finally raised her hand.

“Um, what's the Tower of the Cross?”

Otomigawara was happy to reply.

“I think it would be faster to see for yourselves. Hitsujiko, would you please get the key?”

After Ms. Hitsujiko returned with a key bearing a ring, we took Dr. Iori out of the mansion. We were guided to a cross-shaped building a ways away. The building looked like a giant cross impaled in the ground like a grave marker. It was as tall as a four story building.

“Are you going to lock Dr. Iori in there?” Gentleman asked.

“Yes, right up there.”

Ms. Hitsujiko pointed at the horizontal bar of the cross, specifically, the right side. If you'd like to be morbid, it was the part where Jesus's left arm was during the crucifixion. Because the cross itself was huge, that part was also huge; when viewed from straight in front, the right bar was about 10 meters x 3 meters x 3 meters. Assuming that entire rectangle was one room, it was quite spacious, although unusually long and thin.

That's when I noticed something unusual.

When viewed from the side, the space appeared to be 3 meters x 3 meters. And on the side was a door. Naturally, I had a question.

 

“How do you get to that door?”

After all, that cross was as tall as a four story building, so that room on the right side was probably about three stories off the ground. It was probably impossible to reach even with a ladder.

Ms. Hitsujiko said “I'll show you,” and approached the cross-shaped building. Then she flipped open a hidden cover on the wall. There was a button inside. When Ms. Hitsujiko pressed the button, there was the faint sound of a motor.

And we saw it.

The right bar of the cross slowly descended. Like an elevator, it slid gently down the side of the cross.

After about a minute, the right bar was on the ground. Ms. Hitsujiko inserted the key Otomigawara had asked her to get earlier into the keyhole of the door on the right side of the bar. The door opened outwards, revealing the room.

It was pure white with no windows. As expected, the room was long and narrow; from the door, it appeared to be about 10 meters deep, the same as the right bar of the cross. The room had a sink and a small private room, probably containing a toilet. The room was almost completely empty, featuring nothing but a bed and a basket of canned foods and CalorieMate.

Otomigawara turned to Dr. Iori.

“You'll be staying here until the police arrive.”

Dr. Iori showed another face of despair, but, apparently having come to terms with her fate, just said “Okay,” and entered the room. At least there was enough food to last a person four days. “I'm sorry, but you'll have to drink tap water,” Ms. Hitsujiko added.

When I looked at the inside of the door, it had no thumb turn or button or anything. In other words, it couldn't be unlocked from the inside. After confirming that, we left Dr. Iori in the room and headed out. After Ms. Hitsujiko locked the door with the key, she pressed the button on the side of the building. The room rose back up. Eventually, it returned to its original position as the right bar of the cross.

“Just to be certain, there are no other keys that can free our perpetrator, correct?” Poirotzaka asked, staring at the key in Ms. Hitsujiko's hand.

“Of course,” Ms. Hitsujiko nodded.

“Hmm,” Poirotzaka said, stroking his moustache.

“Then the only thing left for us is to determine how we shall store that key.”

“Oh, we've already decided on that,” said Otomigawara. “There is a way to keep it extremely securely. Hitsujiko?”

The butler nodded. Then she led us somewhere else. It was back to the cottage where Shitsugi, who'd been killed that morning, lived.

Inside the cottage, Ms. Hitsujiko pointed to the north wall and spoke.

“The key is usually kept over there.”

She was pointing at the door with the iron bars over the eye level peephole. I remembered I'd looked through it while investigating the murder. It had been a small room, but the door was locked and I couldn't go inside.

I approached the door and put my hand on the knob. This time, it opened. Beyond the door was a small, square room, about 2 meters x 2 meters.

“I unlocked the door earlier.”

Ms. Hitsujiko took a key from the pocket of her butler uniform. “This is the key to this small room,” she told me.

“But why did you unlock the room?” Yozuki asked.

“Because the key to the Tower of the Cross is usually kept in this room,” Ms. Hitsujiko said, showing us the key to the tower. “So, in order to get the key to the Tower of the Cross, I first had to unlock this door.”

Ms. Hitsujiko pointed to the back wall of the small room. There, at eye level, was an L-shaped metal hook that looked like a bent nail. It was either a hat rack or a place to hang the key.

“As you may have guessed,” said Otomigawara, “the key to the Tower of the Cross is usually hung over there.”

Otomigawara glanced at Ms. Hitsujiko, who nodded and quietly hung the key to the Tower of the Cross on its hook.

“Now, I'll lock the door to this room,” Ms. Hitsujiko announced. “No one will be able to take the key to the Tower of the Cross from this room.”

I see, that was secure. I was impressed. At least, I was in the half second before I realized my mistake. Secure? What was I thinking? This room...

“It isn't secure at all,” Poirotzaka retorted, probably having realized the same thing I had. “Because the door of this tiny room,” he said, pointing at the door.

“As you can see, it has a hole in it! It is barred, but if those bars provide enough space for the key to be absconded with, than one with ill intent could retrieve the key without needing to unlock the door.”

I nodded firmly. That's how it was.

The peephole in the door was rectangular, measuring about 10 cm tall and 40 cm wide. Three iron bars divided it into four square quarters. In other words, there were four square holes of 10 x 10 cm each in a horizontal row. Those were fairly large gaps, so it should be possible to easily put something like the key to the Tower of the Cross through them. For example, the culprit could put a long pole through the gap and use it to hook the key and take it out through the bars.

“Oh, but how wrong you are!”

Otomigawara picked up the key to the Tower of the Cross from the wall. Then she inserted it into the gap between the bars on the peephole. The gap in the iron bars was large enough to admit a person's arm, let alone a key... and yet, the key got caught in the iron bars. To be more precise, the key itself was able to pass through the gap in the bars, but the ring attached to the key was caught in the bars, preventing it from passing through.

“And that's how it is.”

Otomigawara looked smug. I couldn't take it anymore and took the key from Otomigawara to check it properly.

The key to the Tower of the Cross had a thin chain about 10 cm long, and that chain was connected to a ring. The ring was about 20 cm in diameter. That was the part that got caught in the bars.

The size of each gap in the iron bars was 10 x 10 x 10 cm. The length of the diagonal of a square is the length of one side times root two, so the diagonal of these squares was about 14 cm. In other words, the diameter of the ring was more than the diagonal of the squares. Therefore, the ring couldn't pass through the gaps between the bars. The ring, the key, and the chain connecting them were all firmly welded together, so there was no way to remove only the key part and take it.

I was convinced.

This was secure. In other words, unless the small room was unlocked, no one could take the key to the Tower of the Cross. When I checked just to be sure, I saw that there was no way to unlock the door from the inside. That meant the key was the only way to unlock the room.

“Then the question remains,” said Gentleman. “How do we store the key to the room? There's no point in sealing it away if someone can bring it back out.”

Indeed, if anyone could take the key to the small room, than anyone could unlock the door to the room and take the key to the Tower of the Cross. That defeated the point. If someone just went and opened the door to the Tower of the Cross out of sympathy for Dr. Iori, the murderer, she'd escape.

“There's no problem with that either.”

Otomigawara sounded confident. Apparently understanding what she meant, Ms. Hitsujiko opened a drawer set in the wall of the cottage and retrieved a portable safe.

“The key to the room will be kept in here.”

The portable safe was truly strange. It had multiple keyholes, five in all.

“And here are the keys.”

Ms. Hitsujiko laid out five keys on the floor, each different in shape and size. “These...” Gentleman said.

“These are all keys to the safe?”

“Yes, they are,” Ms. Hitsujiko replied. “This safe requires a total of five keys to unlock. If even one is missing, it cannot be unlocked.”

“I see,” said Poirotzaka. “So you mean to claim that if these five keys are spread amongst five different guardians, it will be impossible to liberate the room key from the safe without their mutual cooperation?”

Ms. Hitsujiko nodded.

“That's correct. Of course, none of these keys have spares.”

Poirotzaka grinned.

“Interesting, then I'll protect this one for you all.”

Poirotzaka picked up one of the safe keys lined up on the floor. “Then I will, too,” Yozuki said, also picking up a key. “It looks kinda interesting.” It must have been nice being so carefree. “Then I will as well,” Otomigawara said, taking a key. “I'd like to keep one for myself,” said Ms. Chiyori, taking a key of her own.

“Then I'll take the last one.”

Ms. Hitsujiko picked up the remaining key.

“Now, let's lock the door to the room and put the key in the safe. But first...”

Ms. Hitsujiko looked at the key to the Tower of the Cross in my hand. I nodded and hung it back on the hook in the room. When I stepped out of the room, Ms. Hitsujiko locked the door with the key she'd taken from her pocket. Then, just to confirm, she said:

“Of course, there are no other keys to this room.”

After making sure everyone understood, Ms. Hitsujiko put the key to the small room in the safe. Then she locked the safe with the first key, which she'd been entrusted with. She encouraged the others to do the same, and each person who'd been entrusted with a key locked their keyhole. They went in this order: Poirotzaka, Yozuki, Otomigawara, Ms. Chiyori. The safe was now locked five times over and couldn't be opened.

To summarize the situation, it was like this:

① There is only one key to the Tower of the Cross, where Dr. Iori is imprisoned.

② That key is being kept in a small room in Shitsugi's cottage.

③ There is only one key to the small room in Shitsugi's cottage.

④ That key is being kept in a portable safe.

⑤ That safe requires five keys, each of which is being kept by a separate person.

“......”

It was perhaps too secure. But by that same token, it could be said that for Dr. Iori to escape from the Tower of the Cross was virtually impossible.

Ms. Chiyori gave a dramatic stretch.

“The case is closed, so we have free time until the ship comes to pick us up.” She yawned. “Kasumi, would you like to play some games? Monopoly or something?”

“Oh! I wanna play too, let me join,” said Yozuki, the Monopoly-loving girl. “Ah, I want to play, too,” Otomigawara said in a childish voice.

And so, we passed the rest of the day in peace. We had to. After all, the case had been solved.

We truly believed there would be no more murders.

Leticia Breakfast was leisurely reading a book in the cottage she stayed in on the island. It was a Latin book her parents had sent her. She could only read Latin. Of course, the number of Latin books in existence was small, so her reading pool was limited.

Maybe she should learn another language. Japanese... or at least English.

She thought that as she turned the page. The Latin translation of And Then There Were None was quite interesting. It told a very similar story to the one those on Wire Mesh Island found themselves in. The difference was that the serial murder case on Wire Mesh Island had already been solved.

At that moment, there was a knock on the cottage door. Breakfast, unhappy that her reading had been interrupted, shut the book and headed to the door.

She opened the door. The person on the other side gave her a small nod.

And they said something in Japanese.

Breakfast didn't understand Japanese.

But she could make out four words: “Living Locked Room Library”.

So she could make a guess.

“I am the Living Locked Room Library.”

That was what the person said.

We were looking into the cottage through the window. I couldn't believe it. Even though the case should have been solved... why?

“...Impossible.”

Ms. Chiyori was shocked as well. Her words expressed the confusion we all felt.

Inside the cottage was the decapitated body of Poirotzaka. And next to the cottage bloomed out of season cherry blossoms.

“Indeed, both incidents happened during the cherry blossom season.”

I remembered what Ms. Hitsujiko had said earlier.

Two locked room murders had occurred on Wire Mesh Island before. In both cases, the crime scene was the cottage where Poirotzaka was currently lying, and in both cases, the victim's head was severed.

That had given birth to a certain legend on Wire Mesh Island. If you stayed in that cottage during the cherry blossom season, you would definitely die in a locked room.

And now, those two locked room murders had been recreated right before my eyes.

The four most impossible unsolved locked room murders.

“Japan's Four Great Locked Rooms.”

I lifelessly spoke in defeat.

“The Decapitation Chamber of Wire Mesh Island.”

 

Previous Chapter                                                                                                                                                                                                                                                                                Next Chapter