After Kaito had showed a simple trick to deal with the pachinko machines, the other two didn't have much to worry about. They only bet 0.4 liters each, and while neither of two actually let their guard down, staying wary of possible surprises, the mood was relaxed and nothing unexpected happened. Kaito took the key that was offered upon victory.

Of course, the tension returned when the time came to choose the next game for them to play. There was a tacit decision to let Kokichi be the one to chose what it would be, since the other two had already done so. He did a quick circuit around the room, apparently just wanting to make sure he hadn't missed anything, and then he pointed at the dollhouse that Rantaro had examined prior to the pachinko game.

Both Rantaro and Kaito shrugged and walked there, presuming that Kokichi had a reason for choosing it.

The three of them stood before the table upon which the dollhouse was placed and mere moments later, Monokuma D's voice reached their ears.

"Oh, is this the game you're going to choose? Is it? Is it?" He asked, his eagerness plain as day.

"Nope, sorry." Kokichi answered, causing the virtual bear to groan "Except that's a lie, we really are choosing this."

"Yay! Now that you said it, you can't take it back." Monokuma D spoke happily "So I need to explain." He took a moment to calm himself down "I am proud to present my favorite game of those in this room. This is the Murder Mystery game!"

"Ah, I thought it would be something like this. Should be fun." Kokichi commented.

"Allow me to explain, then." Monokuma D started "This game is different from any of the others in this room by the fact that it is 100% cooperative. All of you will be playing together, and you will either win or lose all together as well.

"The way it works is mostly simple." He kept going "You guys will need to solve a murder mystery by discovering who is the killer. I will give you all the relevant clues and information, as long as you ask the right questions." He paused for a moment "But there is a small wrinkle... Some of these rooms have special rules to them."

"You mean the rooms that have those symbols on the walls and floors?" Rantaro asked.

"Precisely!" Answered Monokuma D "There are four different symbols you need to pay attention to.

"First is the Triangle Calida. In rooms where it is inscribed, people can not stay for more than 30 minutes at a time."

"Is Calida what you call the letter inside the triangle shape?" Kaito asked.

"Yes, it is. But moving on to the second we have the Square Lucien. In rooms where it is inscribed, no living people may remain inside from 10PM to 6AM.

"The third is the Pentagon Arabus. Its rule is that no more than five people can remain inside its rooms at a time.

"And finally we have the Hexagon Omni. The rule associated with it being that upon entering its rooms, people can not leave before at least one hour has passed." He concluded.

Rantaro thought about those rules. It sounded like that was more like a logic puzzle than a true murder mystery. And since the Square room specified living people, it was likely that the body would be in one of them.

"Yeah, that's cool and all, but give me the juicy details already!" Kokichi asked impatiently.

"Alright, alright. No need to rush me." Monokuma D stopped for a moment, and they heard the sound of rustling paper before he spoke again "So, there are 9 people involved in this case. One of those is the victim.

"And since it would be a pain to give names to all of them, let's just say that the victim is number 1, and the suspects are numbers 2 through 9.

"Number 1 was found dead in the morning in the second floor living room, which they use as a games room, and it was clear that he had been killed in the previous day. Do you all understand so far?"

Rantaro quickly thought back to when he had examined the house previously. The only symbol on that particular room was the square. That meant either the murder had occurred in that room or the body had been carried there, and either way it would have happened before 10PM, since the culprit would need to be inside.

"Just to make sure." Kaito spoke up "There are no zombies involved, right? That means the only dead person is the victim, and they will not be able to move on their own, right?" Rantaro heard a strange tone in his words, but couldn't determine what it was.

"That's exactly right!" Monokuma D answered "This is a total fair-play mystery. Nothing supernatural, no secret passages, nothing of the sort."

"And then there's another super important aspect to this mystery." Monokuma D returned to his explanation "All the information you can get about the movements of the suspects is limited to reliable sources, by which I mean if there are two or more people together, so they can provide alibis to each other.

"Since the victim is dead, they obviously can't provide such information, so if they were alone with someone else, this will not be included among the information you have. And yes, you can assume there are no accomplices or such, since that would put the validity of all information into question."

Rantaro thought that the part about the victim was probably obvious, given that they would certainly be together with their killer just before death, and so there would be no mystery if they knew about that. However, it was good to know the thing about accomplices. The format of the mystery already implied it, but a confirmation left no doubt, narrowing the possibilities further.

"So, knowing all those rules, you can ask me for any information you want to know. Please do your best to solve this mystery." Monokuma D concluded.

Predictably, the first to ask a question was Kokichi:

"When was the last time number 1 was seen alive, where and by whom?" He spoke in an almost serious tone.

"The last time they were seen alive was when they were leaving the dining room at 6:00 PM. Numbers 2, 3 and 5 were all there at the same time." Was the answer.

The dining room was on the first floor. The only symbol there was the Hexagon, meaning number 1 had to have been there since at least 5:00 PM, to complete the requisite hour. It also had only one exit, to a connecting corridor that had the Triangle and Pentagon symbols and was the only place connected with the stairs.

"What can you say about the movements of Numbers 2, 3 and 5 immediately after 6:00 PM?" Kokichi asked. He was taking the lead on that game, and Rantaro was fine with it.

"Number 2 had just gotten inside, so they would only be able to leave at 7:00PM or later. Number 3 and Number 5 left at 6:30 PM. They immediately split up, 3 going to the kitchen and 5 remaining in the corridor."

Kokichi stopped and thought for a bit, then he seemed to have hit upon an idea.

"Tell me about the movements of people in the second floor right wing bedroom and staff room, from 6:00 PM to 10:00 PM." He asked.

Rantaro understood. Those two rooms were the only places that had entrances to the body discovery room. Since 1 had been seen alive at 6:00, he would need to have passed through one of those rooms during that time period (whether alive or not) in order to end up there.

Looking at the model again, both of those rooms shared the same two symbols, the pentagon and the hexagon. Then Rantaro had to pay attention since the Monokuma started speaking again.

"There's quite a lot, so let's start with the staff room. At 6:30 both number 8 and number 7 entered from the corridor, and they saw number 4 leave, entering the living room. At 7:30 number 9 got in from the living room, and number 7 left through the corridor.

"At 8:00 number 4 got in from the living room, number 2 got in from the corridor and number 8 left through the same place. At 9:00 number 2 left through the corridor, and at 9:30 number 9 did the same."

The corridor, which was the other exit of the staff room only had a triangle as its symbol. It was also directly connected to the stairs, so it was another place number 1 had to pass through. More things to consider, Rantaro thought.

"Next is the bedroom." Monokuma D took took a deep breath before resuming "At 6:30 number 9 got inside from the anteroom, finding number 6 already there. At 7:00 number 5 got inside, also from the anteroom.

"At 7:30 numbers 3 and 7 came in from the anteroom and number 9 left through the living room. At 8:00 number 8 came in from the anteroom. At 8:30 numbers 5 and 3 left through the anteroom and at 9:00 numbers 8 and 7 did the same." He concluded.

Rantaro observed. The anteroom was connected to the second floor corridor and the right and left wing bedrooms. It had no symbols at all.

"Just one small thing I need to confirm." Kokichi spoke again "Bodies can be hidden, but do the rules allow for someone alive to hide themselves?" He asked.

"No. That is not allowed." The Monokuma spoke firmly.

"In that case, I got it. I've solved the mystery." Kokichi declared with confidence.

+0+

Kaede kept careful attention of everything around her as she made her way to the master room. She knew that there was probably very little she could actually do that would affect whatever plots were going on, but she also knew that she would hate herself if she didn't do what she could.

That was a familiar feeling to her. Not a comfortable feeling, but familiar. And so, Kaede simply kept going, hoping beyond hope that things wouldn't go as badly as she suspected.

Since they had already been in the basement floor, it didn't take any time at all for Kaede to reach the newly accessible room, even with her taking the time to look around. So she took a deep breath and approached the door, which opened automatically to let her in.

As soon as Kaede stepped inside, her Monopad beeped and the timer started running, counting down from one hour. The pianist decided to test something, and stepped back outside the room.

The timer stopped and Kaede nodded, understanding how it worked. She then entered back in the room and finally started to examine it.

There was no question why Gonta had been incapable of giving a concrete explanation about that room. Kaede herself wasn't confident of being able to give a report that met her own standards without needing to spend an unreasonable length of time on it.

First of all, the room was absolutely huge. One could fit a high class theater inside that room and still have space left over. The room was shaped like a hexagon, only slightly elongated.

The room was similar to industrial warehouses, with shelves so high they could only be reached via use of specialized equipment, containing crates so huge they had to be moved via forklift.

Yet, the most striking part of the room were the huge number of conveyer belts that were constantly moving around and sometimes carrying things from the crates that were deposited by huge machines.

"I see you are interested in this room." Came Monokuma's voice.

"Wha-" Kaede was startled, but not because it was Monokuma's voice, but rather due to the fact that the voice came out of her Monopad.

She quickly looked over it and saw that there was a window on the corner of the screen showing the bear.

"Monokuma?" She asked doubtfully. Somehow it didn't feel like him, despite the voice and appearance being the same.

"Indeed, though you are also correct in your doubts." The bear on the screen spoke "I am Monokuma B, while the one you are most familiar with is Monokuma A."

"And why are you introducing yourself now?" Kaede asked, deciding to try and gather as much information as possible given the situation.

"All of us Monokumas have different roles. Monokuma A is the host of the killing game, and as such is the one with the biggest connection with you Ultimates." B spoke politely and in a high-class manner, further highlighting the differences between him and A "My role is that of a manager, responsible for making sure everything works properly, from the supplies for meals to the energy expenditures. Since this room is quite important for that purpose, I decided that now was a good time to introduce myself."

"I see." Kaede replied. That was an opportunity to try and gather some information so she wracked her head to think of what questions to ask, and eventually she decided to start with the most pressing one.

"This place is the little master room, right? Doesn't that mean there is also a big master room or true master room somewhere else? What's the difference?" Her words were calculated. She knew people (though the Monokuma didn't quite fit the definition) were more likely to give information when correcting someone, rather than when they were asked directly.

Whether or not her ploy had been a factor, the Monokuma did answer:

"The true master room is much harder to get into, and you guys most likely will not see it until the game nears its end, if that." He spoke calmly "The difference is that while this room is the main center for the management of your daily necessities and general day to day operations, the true master room is the command center of the entire Killing Game."

Those words echoed heavily in Kaede's mind, but she did not hesitate to keep talking:

"And from what you're saying, I don't think you manage that room as well. But it makes sense, I don't think any of the Monokumas would be allowed to have that much control over things."

That assumption was a shot in the dark, based around several ideas Kaede had about the workings of the game and the sorts of people who would set it up. Speaking to Monokuma B about it was a way to possibly obtain something constructive out of those ideas.

"Tch, you're right." Monokuma B replied with obvious distaste, the first time his polite facade had slipped "None of us Monokumas are capable of getting even close to that room." Then it was back "However, that doesn't mean that you guys would be safe inside. In many ways, the true master room is the most dangerous place within the Killing Game."

Kaede simply nodded thoughtfully. The reason for the lack of a bigger reaction on her part was the fact that she could not be sure whether that information was accurate, or whether it was a lie the Monokuma was programmed to say in response to that question.

And even if the information was accurate, it wasn't like she would be able to do much with it. Making daring plans based on unreliable information was beyond her. At most, she could tell about it to the people who were better at that type of thing and then act together with them.

Also, her current suspicions about the actions of Tsumugi and the others gave Kaede a sense of invisible pressure that made it harder to get excited about such things.

At that point, she heard footsteps from nearby. It looked like someone else had decided to check out the Little Master Room already. Kaede waited until the steps had grown close enough for it to not be suspicious and then turned back towards the entrance.

She was a bit surprised to see that it was Maki, but said girl had been acting strangely since her conversation with Tsumugi. While Kaede thought she wasn't the type to come to that room so early, things changed because of that fact.

"Ah, Maki. You're here too?" She spoke normally, despite all those thoughts.

"Yes. It seemed... Important." Was the reply "Do you know what this is all about?"

"Gonta found this room and was telling people about it, so Monokuma decided to give everyone permission to enter because he thought it would be entertaining." Kaede answered truthfully, like she normally did.

"I see." Maki said "Maybe I should take a look, then."

"If you have any questions, you can ask Monokuma B about it." Kaede lifted up her Monopad to show the bear.

"Monokuma B?"

"He's different from the one we know." Kaede didn't explain further, instead directing her words to the Monopad "Could you connect to her so she can talk to you as well?"

"That would be no problem. Let me just... Hm? Ah, that's right." The image of Monokuma B went off screen while he was talking, and soon after came a beep from Maki's Monopad.

She brought it to her face and Kaede could hear the virtual Monokuma introducing himself. Then she saw someone else going inside the room. It was Tenko, but Kaede barely had the time to greet her before more people arrived. First it was Miu and Keebo together, both of them looking around warily, and just behind them came Angie, looking at ease just like always.

Kaede briefly thought about the others, wondering how long it would take for them to come as well, and whether some would decide against coming at all. However, her thoughts soon returned to the current situation, and she wasted no time in telling the others about Monokuma B.

The more people were in the loop, the bigger the chance that one of them would find something she would not be able to.

During that conversation, however, Maki went on her own to explore the room. Kaede heard her walking away, but continued talking with the others like nothing had happened. It didn't seem like she would be able to accomplish anything by following Maki.

And after Kaede finished speaking with them, three of the other Ultimates decided to explore as well. Keebo and Miu left together, saying something about checking the mechanisms for any useful information.

Angie also left, but not before leaving Kaede with a few parting words:

"Atua knows you're worried, Kaede. But one can only take full responsibility for their own actions, not those of anyone else."

Kaede briefly thought back to her conversation with Tsumugi. This place sure had a lot of perceptive people.

"Thanks for your words." She replied with a smile.

And that was it. Angie had no further replies to make, and so Kaede was left alone with Tenko.

"Do you want to go explore together?" She asked the other girl, who was looking at her in a way that made Kaede think of a dog asking for a walk.

"Yes, yes!" Tenko nodded quickly, grinning broadly.

Kaede made a small gesture and turned to walk towards the interior of the room, Tenko moving to her side and going with her.

The two spent about fifteen minutes going all around the room. And Kaede's previous impression of it was updated with the word "labyrinthine". The comparison to industrial warehouses made for a fascinating contrast: While they were usually ordered rows with a lot of space in between, the little master room was very much not ordered in any way she could see.

It was impossible to see one side of the room from the other, because the rows of shelves were spread around weirdly, sometimes angled to almost touch one another, while other times a passage in between two of them was interrupted by another shelf in a way that created a T-section.

Apart from that, most of the conveyer belts were elevated in the air like suspended bridges, creating walkways that reduced the space available in between shelves even more. It was such a mess that even though they walked for so long, they only saw Maki, Miu and Keebo once (the latter two together), and didn't see Angie at all.

Normally Kaede would suspect that they were avoiding her, but she thought it was simply because the design of the room made it impossible to see more than a few meters ahead in any particular direction, specially when you got deeper into it.

During the whole time, Tenko kept cheerfully talking to her about whatever came to mind (usually thoughts sparked from seeing a particular item among the supplies). Kaede was glad to have company for that exploring, and talked back to Tenko without any reserves. Still, she didn't forget about investigating, and thus spoke a few words to her companion at a certain point:

"Can you imagine playing hide and seek here?"

Tenko blinked and looked around thoughtfully for a few seconds before responding.

"Depends on the type. If it was just hiding until discovered it could be pretty fun, but if it was something like having to sneak around the seeker to touch the start it would be bad." She said "You just need to turn a corner to disappear, so sneaking around is too easy."

'Sneaking around is too easy, huh?' Kaede thought to herself. Tenko had gotten to the heart of the matter. This place seemed to be made specifically to allow others to sneak up on people, but turning that around, it would also make it easy to dodge pursuers.

Soon after that, Kaede heard someone walking nearby. It was a lazy sequence of steps, suggesting that the person was simply wandering around like them, but it was notable for the fact that sounds didn't really carry easily in that room, so even Kaede could only hear steps from very close by.

"Oh well, let's keep going." Kaede said casually, and walked forward closer to the source of the sound. Tenko followed her like a matter of course.

It took less than ten steps before Kaede turned a corner to see the owner of the previous steps, Tsumugi.

"Ah, hi Kaede." She greeted, and did the same for Tenko when she saw her.

"Hi Tsumugi." Kaede replied "So you finally came here."

The pianist had honestly thought that Tsumugi would have been one of the first people to come examine the Little Master Room, so she had been surprised when that wasn't the case.

The exploration together with Tenko had already taken a bit more than half an hour, though of course Kaede could not be certain of when exactly Tsumugi had entered.

"Maki asked me for a favor, so I was busy for a bit." Tsumugi said.

"Oh, a secret favor?" Kaede asked with a grin "It's nice that you've been getting along with Maki. She feels like she really needs a friend."

Those words were Kaede's true feelings. She was obviously concerned about Tsumugi's intentions towards Maki, and what kind of plans were in the works, but she truly felt that Maki being able to trust someone enough to work with them was a positive change for the girl.

"I know." Tsumugi replied with a slow nod "Seems like you two are exploring this place." She said while looking at Tenko, who had been simply watching the conversation from the side, as if she wasn't sure whether she could participate.

"Yeah, we are." Said girl responded "Do you want to come with us?"

"Are you sure I wouldn't be intruding?" Tsumugi asked, as if she hadn't actually already decided whether to go or not "How about we just share information?"

"Did you notice something interesting?" Kaede asked, knowing this was probably playing right into Tsumugi's hands, but deciding to try and experience as many of her cards as possible to get information.

"Yeah. You see those conveyer belts that take things from one place to the other? The paths they go through are forbidden for students to cross, so even if you managed to smuggle yourself inside one of the supply crates, you wouldn't be able to get here." She spoke brightly.

'Unless you're Gonta.' Kaede thought in her mind, finally understanding how the boy had managed to find this place.

"Ah, did Monokuma B tell you that?" Kaede asked, not letting her thoughts interfere with the conversation.

"Yeah." Tsumugi confirmed "He suddenly started talking to me through the Monopad, so it was pretty surprising."

"I can imagine." Kaede said dryly "But I guess you want to explore by yourself for a little bit more, so let's split here." She smiled "We can talk about what we learned once we're outside and not under a time limit."

Tsumugi agreed to Kaede's suggestion, and soon she had went off on her own, while the duo went in another direction.

+0+

Still, the time they had to explore the room had always been limited, and not much more of note happened besides the two seeing that both Korekiyo and Ryoma had come to explore as well.

Soon enough, Kaede's Monopad started beeping loudly, and she looked at it to be met with a warning that her allotted time in the Little Master Room was almost running out. Furthermore, if Kaede didn't leave before then, she would be considered a trespasser and summarily executed.

Tenko would receive the same warning a slight bit later, so she elected to leave together with the pianist. And despite the layout of the room being what it was, it didn't take long for them to go back to the entrance.

And after walking out, Kaede sighed. She was pretty sure something terrible was going to happen inside, but she had done her best and yet couldn't find a way to prevent it. Maybe someone else could, but it was now out of her hands.

"Did something happen, Kaede?" Tenko asked.

"Just hoping that they do alright." She responded with a shake of the head.

Kaede knew just brooding about it would do no good. She could only prepare herself to try and help with the inevitable fallout.

Just like always.

+0+

"Really?" Kaito asked with surprise, reflecting Rantaro's own feelings.

"It's pretty simple, actually." Kokichi said with only a small trace of smugness "You just have to rely on your little gray cells."

"Then could you explain to us so we're all in the same page?" Rantaro asked.

"Sure!" Kokichi agreed readily. It seemed like he really wanted to show off "We begin by realizing Number 1 got into either the bedroom or the staff room at 6, rather than only later.

"We know this because from 6:30 to either 9:00 or 9:30 there were always at least two people in each room, so they would have been spotted if they entered at that time. And here's the trick: The hexagon rule does not exclude dead people."

Rantaro had a moment of realization. The phrasing of "no living people" implied that dead were considered people as well.

"Because of this number 1 could not have reached the living room, since they would have to spend 1 hour in the neighboring room, only being able to move at 10:00 or 10:30, when they could not have walked inside the living room or been carried, as either would imply a living person breaking the rooms rule." Kokichi explained in detail, causing Kaito to emit a sound of agreement.

"So number 1 must have entered one of the two rooms at 6:00 PM." Kokichi resumed his explanation "As such they could not have left before 7:00 PM due to the same hexagon rule. By that point there were witnesses, so they would had to have been killed during the brief 6:00 to 6:30 period and then hidden in the room."

That was also pretty logical, Rantaro thought.

"Then, once the time of no more witnesses arrived, the culprit could have carried the body to the point of discovery. Since there are no restrictions on how long to remain there, even the 9:30 room person would have had time to place the body and then leave." Kokichi kept going "They would need to wait another hour on one of the neighboring rooms due to entering it again, but there would be no broken rules."

Rantaro understood what Kokichi was getting at. Number 4 in the staff room and number 6 in the bedroom were both suspects, since they had been alone in their rooms before 6:30 and had remained once all others had left.

"And so, there are seemingly two possibilities for the culprit. The only ones who had the opportunity to do all that." Kokichi stopped for effect "But as it turns out, there is one room that could not have hidden the body... Because of the pentagon."

There was a moment of incomprehension as both Rantaro and Kaito tried to understand. And then it clicked.

"It's the same as the hexagon." Kaito was the one to voice it "It doesn't exclude dead people."

"That's right. And at 8:00 in the bedroom, there were five living people. Numbers 3, 5, 6, 7 and 8. If the body of number 1 had been there as well, it would make 6 people in total, breaking the 'five people only' rule of the pentagon." Kokichi said "As such, the only one who could have committed the crime is number 4. Do you guys agree?" He asked the other two.

"I agree." Rantaro answered with a slight smile.

"I definitely agree." Kaito said.

"In that case, this is our answer. So, Monokuma D, are we right?" Kokichi asked.

There was a brief pause and then:

"You are right!" Monokuma D played the sound of a casino jackpot, and then the table opened itself, revealing a hollow space with a third key, which Kokichi took.

"Congratulations on beating this Dead Room!" The virtual bear spoke as a piece of the wall moved upwards, revealing a door "... Almost."

The three looked at each other before walking towards the door. It had a number-pad. Of course.

"You are just one step away from being able to obtain your prizes." Monokuma D spoke "You just need to deduce the right combination of six numbers. Your only clues are that the numbers are tied to what games you played and in what order. You have five attempts, but failure will just mean being sent away without anything. Please try with no worries."

Kokichi looked at the other two for a few moments, a tacit understanding forming. Then he extended his hand and put in the code 102004. The door immediately unlocked.

'Well, that sure happened.' Rantaro thought in bemusement. 10 from the missing card, 20 from the number of holes in the pachinko machine and 4 being the number of the killer. Not really a hard code to figure out.

The door opened.