...

“Huh?” Aiko breathed in surprise as she found herself suddenly in motion. Yuichi touched down some ways away, in that same instant, she saw a wall appear in the space she had just been.

A wall of ice had formed between them and the stage, crackling frigidly.

Kanako looked just as surprised as they were, which suggested to Aiko that she wasn’t trying to hurt them. She just didn’t want to be interrupted.

The wall of ice Kanako had made was less substantial than Rochefort’s — it was thin, brittle-looking, and fully transparent — but it seemed that buying time was all Kanako wanted to do, and she ran backstage and disappeared.

Yuichi struck the wall of ice with his fist. He easily opened a hole in it, but that didn’t bring the whole thing crashing down, and the hole he had opened slowly filled in.

“Dammit! We’ll get outside and head her off around back!” he shouted. Giving up on destroying the wall, Yuichi ran for the exit.

Aiko was about to run, too, when suddenly, the whole gym began to shake with a loud noise.

“Huh? What? An earthquake?” Aiko instinctively crouched down. It felt like something big was happening.

The shaking quickly subsided, and the next thing Aiko knew, Yuichi was at her side.

Just as she was beginning to wonder if the earthquake was Kanako’s doing, too, she heard the sound of static coming over the speakers.

“I will now explain the game. I’ll only say this once, and I will not take questions. There are three basic rules:

“One, violence is prohibited.

“Two, If you lose your right to exist, you die. Check the back of your hand, please. You should see the Roman numeral III there. That represents your right to exist. When you begin the game, all players have three, and you each lose one every hour.

“Three, players can gamble these with each other in any way they wish. I guarantee that all debts will be paid.

“This ends the explanation. There are other rules, but you can learn them as you play. Now, let’s start the game.”

The announcement came without warning, then cut off just as abruptly, allowing no room for discussion.

“Is that... Miss Shikitani?” Aiko asked. She had recognized that blunt way of speaking.

Aiko looked at the back of her hand, and indeed, she did see a “III” hovering in the air above it. It was vaguely luminescent, like a hologram.

Yuichi also checked his hand. “Shikitani’s ability? But I thought she could only use it in enclosed spaces...”

Aiko remembered him explaining about that in Tomomi’s restaurant.

“What ability? Does that have something to do with these numbers appearing?” Mutsuko asked, and Yuichi explained: Makina’s abilities included “Sealed Room Game,” which let her set the rules in an enclosed space, and “Inviolable Domain,” which protected the objects necessary to keep the game going.

After hearing the explanation, Mutsuko tried bopping Yuichi with her fists in a mock tantrum, but they never reached his head. They just deflected and slipped off of him, like he was made out of rubber.

Next, Mutsuko lightly rapped her own head. This time, it hit. There seemed to be nothing preventing someone from touching oneself.

“So ‘Inviolable Domain’ forbids violence against others, I guess,” said Mutsuko. “I wonder if I could commit suicide? Or poison people?”

“Don’t even speculate,” Yuichi said. “We’re not gonna go along with that creep’s game.”

To check for himself, Yuichi reached for Mutsuko’s face, and his hand slipped off this time, too.

“What do you think of this, Yu?” she asked.

“If you could control your vectors perfectly, maybe...” Yuichi said.

“I see... I don’t suppose I can ask how you knew about all this, Yu?”

“...I don’t want to say yet,” Yuichi replied after a moment’s thought.

He must still be keeping Monika’s existence a secret from Mutsuko. Maybe he just didn’t want to rely on his big sister for everything.

“I see,” said Mutsuko. “Never mind about that, then! Let’s head for the new school building to do something about the person who made that announcement!” Even at a time like this, Mutsuko clearly couldn’t restrain her excitement.

As they left the gymnasium, Aiko turned her eyes to the new school building, then froze.

“Um... wait... what?” Aiko looked to Yuichi for explanation.

“You think I understand it?” Yuichi answered in an utterly baffled tone of voice.

Aiko looked at the new school building one more time to confirm.

The tip of the inverted castle was sticking into the building’s roof.

It was around 5:00 PM by the time they arrived at the new school building’s entryway hall. It should have still been light outside at this time of day, but everything was rather dark, thanks to the fog.

The school building interior was unchanged, despite the spire of a castle sticking into it, but the students inside were far from unaffected.

Confused crying, level-headed discussion, reckless running around: their reactions were all over the map.

“It’s no use! We can’t leave the school grounds!” a group who had been checking things outside reported back.

“You mean it’s not just the fog?!” somebody else cried.

“There’s something like a wall there! And we can’t get through it!”

This was Makina’s “Inviolable Domain,” the defensive field that protected things necessary for the game. It was probably covering the whole school.

Even the students who doubted the situation at first gradually seemed to be coming around to believing that the announcement was true.

The numbers hovering over their hands; the fact that they couldn’t escape; the transparent membrane that covered each of the students, forbidding violence... It was all evidence that the rules stated in the announcement had been true.

“So, what do we do? Head for the broadcast room?” Yuichi asked Mutsuko. They had made it to the new school building, but he noticed that she didn’t seem to have a game plan past that.

“First, to the roof!” she declared in response.

“You’re not just saying that because you want to see the castle up close, right?” Yuichi asked dubiously.

Mutsuko showed him her tablet, which was streaming video from the roof.

He could see the castle tower intersecting with the roof, but there was no destruction. The joining was a clean one, as if they were co-existing in the same space. It looked like a piece of avant-garde sculpture. There was a woman in glasses there, too, walking along the roof.

Yuichi recognized her. It was Makina Shikitani.

“If she was the woman who made the announcement, then she’s clearly the cause of all this!” Mutsuko declared. “If we can just do something about her, then we’ll have time to work out Orihara’s problem afterwards, right?”

“I’d be more surprised to hear she didn’t have anything to do with this, yeah,” Yuichi remarked. She had said it was a secret, but maybe Makina’s original goal had been to get everyone in the school involved in her game.

“Let’s proceed with caution!” Mutsuko declared. “She might have set some traps on the way!”

“You look pretty happy about all of this, Sis...” Yuichi was feeling a bit fed up with his sister’s eternal optimism.

“By the way, where’s Takeuchi?” Aiko asked, as if only just remembering her.

“We don’t have time to search, but knowing her, she’ll figure it out on her own,” Yuichi said. They hadn’t run into Natsuki since parting ways in the club room, when she had said she would be searching for Kanako in the new school building. Aiko seemed to be worried about her, but that couldn’t be their priority right now.

The group started heading for the roof. Mutsuko’s prediction about traps proved wrong, and they easily reached it.

Nearly the entire roof was dominated by the castle’s upside-down tower, but there was no sign of damage to the structure itself, confirming that there was some kind of supernatural phenomenon at play.

Yuichi looked up and saw the castle itself, even more massive than the tower already spearing the roof, and the vast stretches of land further up. The scale of it was so enormous, it made it hard to judge distance properly.

“If this is the tip of Castle Zalegrande, that must be the Demon Lord’s living space.” Mutsuko pointed to the upside-down veranda. “It looks like the woman in glasses got in through there.”

“We’ve come this far,” Yuichi said. “We’ll just have to go inside.”

He approached the veranda and peeked inside. It was a disorienting sight, with the ceiling and floor reversed. Thinking about it, the roof should have reached the third floor of the school by now, but they’d seen no influence from the castle there, suggesting some kind of dimension warping phenomenon must be involved.

The room didn’t have the eerie sort of atmosphere you’d expect from a room in a Demon Lord’s castle. It was done up all in white, and overflowing with good taste.

“How do we get in?” Yuichi asked. If they just jumped in, they’d drop to the ceiling, which was about five meters down. Yuichi would be okay, but he had his doubts that Mutsuko and Aiko could land safely.

“Yu, why don’t you go in first and catch us?” Mutsuko asked.

“Yeah, that’s probably the best option.” Yuichi stepped in through the veranda window, readying his body to absorb the shock of the fall.

But his expectations were immediately betrayed, as his sense of up and down was suddenly flipped.

“Huh?” Yuichi was falling not towards the ceiling, but towards the floor, head-first. He quickly planted his hands, rolled forward, and righted himself. He looked up and saw Mutsuko and Aiko, watching him through the window, upside-down.

“Gravity inversion?!” Mutsuko exclaimed. “That’s so cool!”

“So much has happened that I’m not as surprised as I feel I should be...” Aiko muttered.

Mutsuko was overjoyed about it, but Aiko’s feelings seemed more mixed.

“If we’re just falling to the floor, that isn’t too bad,” Yuichi said. As long as they took their time, it shouldn’t be a problem for them.

Mutsuko and Aiko entered carefully, clutching the windowsill. The minute they were inside the castle, their sense of up and down seemed to flip, though after a moment’s disorientation, they got used to it.

Yuichi looked around the room again. It was a beautiful space, done up all in white. The large canopy bed in the middle suggested that it was a bedroom.

“Where did she go?” Yuichi wondered. There was no sign of anyone in the room.

“Good question,” Mutsuko said. “If it’s like the novel, this is the White Tower. If you go through the door across from the bed and follow the passageway, you’ll get to the Black Tower. If you want to go somewhere else, you’d have to go down the stairway.”

“Let’s go to the Black Tower first.” Yuichi’s judgment was based purely on the thought that it would be annoying to have to climb back up the stairs once they’d gone down.