My Vampire Older Sister and Zombie Little Sister Volume 2 Chapter 5

I had to watch the bright sunrise from the road outside the luxury hotel.

But I suppose seeing the sun at all was better than the alternative.

We had made it through another night.

We had won the 2nd round.

But that only meant the hands of the grim reaper's clock had advanced one more step.

The Five Battles Precipice. The demon of statistics.

We only had the 3rd and 4th rounds left to work on this. We had to find something to destroy the nationally broadcast Colosseum and drive out the Bright Cross before the fated 5th round began.

Perhaps due to shaking off the Leanan Sídhe's curse, I felt full of energy. But that did not cheer me up.

…What would I do about Itou Helen?

I knew she could heal her wounds and recover her lost stamina to an extent by shedding her skin like a snake. But she might have broken her ribs this time. Could she heal something as bad as broken bones just by shedding her skin?

This acc.u.mulation was what created the merciless rules.

I had to do better. The Five Battles Precipice did not mean we were safe until the 5th round. It meant she would die in the 5th round or earlier. So she could have easily been killed back there.

So I had to hurry it up.

I had to find a way to save Itou Helen.

"Maxwell."

"Sure."

"Did you find anything in common between the 1st round's TV station and the 2nd round's luxury hotel?"

"A few. First, the broadcast equipment and staff used for the 2nd round were the same as at Kukyou 1st Broadcasting. And that obviously includes the bunny girl. Also, both facilities are part of the same economic cooperation organization. That organization appears to gather the opinions of the financial world and pa.s.s them onto the political world, but it is no more than a decoration started by a specific politician. In other words, it is no more than a briefing that eliminates any opinions deemed inconvenient to Kukyou City's elites."

"I'm not entirely sure what that means, but are you saying they're guilty?"

"Incredibly so. This is a textbook example of corruption."

…If they were that bad, then I was in danger just having that information, but that s.h.i.+p had sailed long ago. There was no chance of safety from the moment I had chosen to oppose the Bright Cross.

"Also, this information is not certain, but I think I will provide one warning as a simulator."

"I am a handmade disaster environment simulator that you constructed singlehandedly, but I take pride in my processing power's lack of inferiority. …And yet you have run across too many unexpected situations lately. I can only call this odd."

"…You say that, but isn't that just because we don't have enough data to build a proper simulation of the abnormal Bright Cross? That's why your calculations aren't perfect."

"I am saying not even that can explain it anymore. For one thing, the very beginning of this incident was odd. On the very day we had decided to head underground and destroy the Bright Cross, they had already withdrawn from that facility and started this public Colosseum. Why? Doesn't the timing seem a little too perfect?"

"…Are you saying they predicted our actions?"

"Sure."

"Maxwell, is it possible you're being hit by a cyber attack? Have you been checking the size of the data transfers?"

"You cannot trust the answer from a possibly infected system, but I can find no trace of an attack. I am monitoring all packets, but I cannot find a single byte outside of the requests from myself or from you. You can review all of the results if you wish."

Maxwell's simulation data was set up to be sent to the college and research inst.i.tutes that a.s.sisted in his construction…and the Bright Cross had influence there. But I supposedly had an additional program in there fooling the system when it chose that path. At this point, I doubted I had just made a simple programming error. The syntax was simple enough and, if there was a mistake, Maxwell would have sent a flagged warning during the testing in a virtual s.p.a.ce.

But wait.

What if…?

"…Isn't this really bad, Maxwell?"

"Sure. If there is no issue with my specs and no sign of data being stolen in a cyber attack, then only an extremely serious possibility remains."

In other words, the Bright Cross was doing the same thing.

Just like us, they were running simulations with a largescale processing device to detect when disaster would befall them and to construct a countermeasure to stay ahead of it. That was why we were not doing any damage to them.

Or to put it more simply…

"It is possible the Bright Cross has a simulator much like myself. And I can estimate that they have gone a step beyond us and given it greater specs than my own."

"You're…kidding…"

"No. I have not been given such flexible conversational ability. Everything I say is serious."

I felt a chill in my stomach instead of my spine.

That possibility was far too devastating. A normal human - and only a high school boy at that - had only been able to get this far thanks to my unfair reliance on Maxwell.

If they had a computer more powerful than Maxwell, I would lose that advantage.

And while Maxwell was my masterpiece, we were only talking about a handmade machine limited to a container in size. There was nothing I could do if they brought out a nationally-funded supercomputer larger than a gym!

But if that was the case, then I was back to being nothing more than a high school boy. It was like being thrown into the back alleys full of guns and Archenemies with no weapon to speak of.

And it did make sense.

Kukyou City was a regional city where the disaster prevention business was booming, so a lot of effort went into developing supercomputers and simulators. The Bright Cross was a group that fought the Archenemies that they called disasters. If their tendrils really did stretch to every part of the city, it would be odd if they didn't use those handy supercomputers.

Also, what was the Five Battles Precipice again?

How had they calculated out and built up the theory of that demon of statistics? They couldn't exactly work it out in their heads, so they would use a supercomputer or simulator.

"User, this is a double-edged sword."

As a program, Maxwell did not feel despair. Even if he knew he was inferior, he would suggest the optimal solution to the current situation.

"The Bright Cross's simulator is indeed the greatest threat at the moment, but it is also their Achilles' heel. If we can locate it and attack it, the Bright Cross will lose their eyes and ears. If their simulations stop, my proposed strategies should have an effect once more."

Perhaps so.

But where was the Bright Cross's unseen computer?

To reiterate, Kukyou City was a disaster prevention city that worked at developing disaster countermeasures. With the university, corporations, and research inst.i.tutes, there were plenty of supercomputers or simulators for them to use. It was also possible that the actual computer was located on the other side of the planet and they were only connected by a high-speed line.

What a pain.

This was like searching for buried treasure in a minefield. The words "safety" and "certainty" just kept slipping further and further away.

"Pin pon pon poooon! Huh? You don't look too happy. Did something happen?"

I arrived back home shortly after 5 AM.

That was more than 2 hours before when I usually woke up. I wanted to get what little sleep I could, but could I really just flip a switch and fall asleep? And a video chat arrived before I could find out.

I had no idea how much she knew, but the blue bunny girl was acting as naively as ever.

"Look, look. It's everyone's idol, Karen-chan. Do I need to lean forward and squeeze my t.i.ts together to emphasize the cleavage? Okay, look heeeeere☆"

…Of course I still looked.

I mean, I might as well. I wasn't serious about it, but why should I reject what's offered to me? That would be immature. Okay, fine. I'll admit it!! Just how perfectly had she simulated the creature known as Amatsu Satori!? It was scary!! (Stare, stare)

"What do you want…?"

"Don't say that after staring so intently at me like that. Oh, or are you more of an a.s.s man? Did you know you have to tug at a bunny costume to keep it from riding up in your b.u.t.t?"

…I wanted her to just get on with it, but if I complained, would she show me more?

"Tah dah! It's time to announce today's subject: your opponent for the 3rd round."

"Wait, wait, wait!"

I had to stop her there.

This was no time to be staring at that jewel-adorned cleavage!

"We only just finished the previous match! You're already putting together the next one!?"

"Hanyanya? Did we ever mention a rule about a set number of days between matches?"

Kh…

Since Itou Helen was learning to use her power as a witch, were they trying to end this before she could grow any further? Or was this all progressing according to the scenario calculated out by the Bright Cross's simulator?

Either way, this was bad news for Itou Helen who might have damaged her bones. She would finally have to fight with her previous injuries intact.

The Five Battles Precipice.

The demon of statistic was clearly beginning to bare its fangs during this 3rd round.

The blue bunny girl winked, gave a glimpse of her canine teeth, and put on a perfect smile.

"Your opponent in the 3rd round will be the brown-skinned Muramatsu Yukie! And what's this!? It says here she's a dark elf!!"

What? A dark elf?

"Wait, are you sure about that? …That's a legit Archenemy and not just an RPG species? This is feeling even more fantasy-oriented and otherworldly than vampires or zombies. Archenemies can go that far?"

"Now, now, Mr. Second. All Archenemies are fictional beings. We can't allow even one of those to exist in the real world, now can we?"

"Kh."

I thought the pressure of her smile was going to make me drop the smartphone.

I knew trying to figure out how the insane Bright Cross thought was a hopeless task. But what was with their hatred!?

"Anyway, that's everything I needed to tell you. As before, we give both sides only as much information on the other side as we can without getting in the way. …Although Itou Helen has fought two rounds now, so the recorded footage will provide a lot of data. Hee hee. Like the way she screamed from the hit to the ribs below her cute chest."

"You…!!"

"I haven't done anything. And I won't tell them any of that. Then again, this is a serious battle with your lives on the line. They would have to be pretty stupid if they didn't go over that footage countless times and ultimately notice it. I expect they'll aim for her side to see how she reacts. Ah hah hah!!"

She ended the video chat.

…Yes, this went beyond direct injuries and exhaustion. A lot of information about Itou Helen was known now. The first-time fighters had all of their information hidden, so our disadvantage would only continue to grow.

Was this also a part of the Five Battles Precipice?

If so…

"…I need to work extra hard."

It was up to me to make up for our handicaps and difference in information.

This time…

Yes, this time I truly had to support her as her second.

I would do the detailed research afterschool. I planned to use the city library and used bookstore that had come in handy (or that had harmed me?) when researching Hanesaki Minori the Fairy, but the time in school pa.s.sed painfully slow. The hands of the clock barely seemed to move at all. I wanted school to end as soon as possible, but the boring cla.s.ses refused to free me.

I visited the school library during lunch, but that may have mostly been a way of reducing the pressure and tension inside my chest instead of a way of actually accomplis.h.i.+ng anything.

The library accepted requests and donations from students, so it had more than just encyclopedias and medical texts. It had probably started with someone bringing in a stuffy hardcover novel that had won some award or another. There was no manga, but there were plenty of fairly light-looking novels on the shelves.

Our next opponent was a dark elf.

…To be honest, it did not feel real at all. Vampires and zombies might not seem realistic either, but this felt like another level entirely. It felt like something you could never see while on earth. If you wanted to see a dark elf, wouldn't you need to create a magic gate and travel to another world?

I felt shocked it was even possible to meet one.

I grabbed the books from the shelves that seemed related, but the only ones that actually used the term dark elf were the light novels with manga-style ill.u.s.trations.

But.

The reason this felt so surreal may have had to do with their high "quality" as an Archenemy. They seemed more unrealistic and more otherworldly. Simply put, they felt like another step toward being a monster beyond a vampire like Erika or a zombie like Ayumi.

"Satori-kun, what are you doing in here with such a grim look on your face? …Hm? Searching for a novel???"

The Cla.s.s Rep suddenly appeared.

Her uniform looked so impeccable I had to wonder if she had it dry cleaned every day.

"It's rare for a digital human like you to come here. But that one isn't very good. It says in big letters that it's getting an anime adaptation, but I don't have much interest in those late night shows."

And growing harsh when it came to books may just have been the way of literary girls.

…Late night anime was not a bad companion for late night work. Y'know, like how housewives watched the midday dramas while ironing the laundry.

When carefully soldering circuit boards or wiring up large machinery, doesn't your mind just seem to boil if there isn't any background noise? Or is that just me? I kind of want to hear that I'm not the only one working at that hour.

"Do you read that kind of thing, Cla.s.s Rep?"

"I read anything that looks like a book."

Wow. That was worse than I thought.

I could guess she was like the vice princ.i.p.al: ask her for a recommendation and the list will never end.

"What are you looking for, Satori-kun?"

"Well, a book with an elf in it. No, wait. I guess it has to be a dark elf."

"…I feel like you're entering a deeply sinful zone here, Satori-kun."

She sounded exasperated, but she still grabbed a few light novels from the shelves and handed them to me.

Again, this was surprising. I hadn't expected that straitlaced Cla.s.s Rep to be into fantasy. …Or did this mean they weren't as light as they might appear?

"You need to thank the vice princ.i.p.al."

"He's apparently a strictly literary kind of person, so he sponsored this library. He even lamented that he had wanted to be the advisor for the literary club or theatre club. He apparently donated his own books."

…Huh? Did that mean this Our Princess Went Delinquent and Became a Dark Elf 2 or this As a Master Strategist, I'm Unmatched in this Fantasy World 17 belonged to the vice princ.i.p.al? And the t.i.tles were pretty long for how silly they were!

"Come to think of it, Cla.s.s Rep, could you tell me what a dark elf is?"

"That depends on what definition of elf you're using," she immediately answered. "The human-sized elves from Norse mythology and the palm-sized elves from England are completely different things. Although the English ones are more commonly referred to as fairies these days."

We had fought a fairy in the 2nd round.

In that case, I doubted that was it.

"Let's start with the Norse ones."

"Norse elves look just like humans. It isn't clear if they actually have pointed ears, but all the texts agree that they are beautiful. Now, there are actually two kinds of elves: the Ljósálfar and the Dökkálfar. Their names simply mean Light Elves and Dark Elves. Fits the fantasy image perfectly, doesn't it?"

"How are they different?"

"Who knows. The Dökkálfar are said to have dark skin and wicked hearts, but that's mostly just for the convenience of the stories. The only differences that are known for sure are the skin colors and where they live."

"Then what do elves as a whole do? Like, do they wield swords or spears?"

The Leanan Sídhe had used two clubs.

Itou Helen's gla.s.s wand could be used as an excuse to have us fight an Archenemy with a weapon. A master swordfighter would be enough of a threat.

But the Cla.s.s Rep shrugged.

"I don't know."

"Hm?"

"Stories tend to have them swinging around swords or firing bows, but I don't think anyone can tell you what their sword is made from, how it's made, or what shape it's made in. The same goes for how elf sword fighting is different from the human equivalent. All we know is they probably move similar to a human since their bodies are so similar."

…This was too broad. This opened up the possibility of an expert in the Yagyu s.h.i.+nkage-ryu. It was useless unless we could narrow it down further.

"Then is there nothing only an elf can do?"

"Hmm…"

The Cla.s.s Rep thought for a bit and then stopped moving.

"No, I don't think so."

"What?"

"Or rather, elves just seem like pretty people who live in the forest. Fantasy stories tend to depict them as skilled in magic or archery, but it never seems like something a human couldn't do if they trained hard enough."

If they were exactly the same as humans apart from their long lifespans, it was true an expert sword or spear user would be frightening, but if that was all, a Yagyu s.h.i.+nkage-ryu elf would not be all that hopeless an opponent. They would be a threat, but Itou Helen would be able to handle it with all her control over supernatural phenomena.

Which left one other thing to ask about:

"You mentioned something about England earlier. What can their elves do?"

"I don't recommend mixing knowledge on the two." The Cla.s.s Rep smiled bitterly. "But in that case, it would be elflock and elfshot."

"What?"

Even video game magic was more creatively named than that.

It sounded lot more like English than the Ljós-whatever and Dökk-whatever, so I could see that this was from England.

"Elflock is a prank in which they tangle up or tie up someone's hair or a horse's mane."

"…That sounds useless at first, but it's probably a real pain to deal with."

"When a rope gets all tangled up like bird's nest, that's elflock."

So like tangled wires?

In that case, my house may have been infested with invisible elves.

"And elfshot is a sudden, intense pain that people feel. It has a number of effects. It can cut the skin like a Kamaitachi, it can paralyze the body, or you can suddenly find a bruise out of nowhere. I think it's supposed to be a wound from an invisible flint arrow or an invisible fire iron."

"…Hm?"

She sounded so casual, but there it was.

An attack from an invisible arrow or fire iron could indeed be deadly.

"But it's not the most credible idea. In Germany, they apparently refer to a trick back as a witch's attack, so this might just be a slang term."

I see.

If it really was just a saying, it might have nothing to do with the actual creature. They say to let sleeping dogs lie and to not cast pearls before swine, but there was no point in taking those seriously and using them to come up with a countermeasure for the wild beast.

"…By the way, Cla.s.s Rep, you know an awful lot about this kind of thing."

"(…Only because I studied up to get along better with your family.)"

School was finally out.

There were 2 things I had to investigate.

The first was of course Muramatsu Yukie the Dark Elf, our opponent in the 3rd round.

And the second was the Bright Cross that ran the Colosseum. Specifically, I had to look into the possibility of a simulator with higher specs than Maxwell.

…They were both important, but it seemed to me the simulator was the bigger deal. As long as it existed, I felt like any of our planes would be predicted and crushed in advance. And if its specs really were greater than Maxwell's, there was a risk they could force their way through his defenses using the brute force of their machine power.

To put it another way, things would be much easier as long as we could crush that mysterious simulator in advance.

"User, what shall we do?"

"…I want to narrow down the conditions first. Is their simulator in the city or outside it? Let's start with that."

This would be a lot simpler if it was outside the city.

At first glance, having the actual computer on the other side of the planet sounded worse, but this was Kukyou City. It was a scenic location surrounded by the ocean and the mountains, but it had been used as a penal colony long ago and it could be easily isolated if a few bridges and tunnels were blocked. That was why it had been chosen for experimentation on and possible disposal of Archenemies.

And the internet lines were no different.

No matter where in the world the enemy supercomputer was, there were only so many thick lines connecting to the outside world. If I cut those lines, the Bright Cross could no longer receive data from the simulator. Its support would be over and that would be that.

I of course had to worry about satellite and wireless connections, but I could cut those off with a few extra steps.

If the alternative was sneaking into a strictly-guarded facility and blowing up a supercomputer larger than a gym, heading into the empty mountains with some wire cutters was far easier.

Conversely, this would be a lot trickier if the simulator was inside the city. There were only so many thick lines out of the city, but the thin lines and weak WLAN connections spread across the city like a spider web. In that case, a cut line or two could easily be bypa.s.sed. I wouldn't be able to stop it without destroying the supercomputer itself.

"Then to start with…"

"Yeah," I readily agreed. "Let's cut all the thick lines out of the city and see what they do."

When I returned home, my little sister Ayumi was upset.

"You're late, Onii-chan! If you were going to be late for dinner, you should've sent an email. I was starving sitting there in front of the food waiting."

"Sorry, sorry."

"Also, Onee-chan is using the microwave to reheat the cabbage rolls she made, but she's smiling and really p.i.s.sed, so you should just bow down to her. Any terrible excuses would just add fuel to the fire."

"Seriously? Today was her day to cook!?"

She looked like a queen, but she was actually a big sister who truly cared about her family. The whole family did not gather often since she was nocturnal, so she liked to make the most of that time.

And when I responded to her cabbage rolls with a satisfactory prostration, she sighed and used her regretful legs to gently step on my head. She wore the same uniform, but she was entirely different from the Cla.s.s Rep. Talk about an oppressive aura!!

…And unlike in the long skirt of her gothic lolita dress, the nocturnal school uniform gave me a perfect view of her 120% adult panties, but I of course left that unsaid. Kh, they're blood red! But Ayumi said any terrible excuses would just add fuel to the fire!

Eventually, we all ate together.

For my nocturnal vampire older sister, this would be like breakfast.

"But why your special cabbage rolls? Is this some kind of anniversary?"

"…Oh, the internet is acting up and I couldn't view any of the recipe sites, so I thought I would make the cabbage rolls since I know how to make them by heart."

My older sister would puff out her cheeks if I fiddled with my smartphone during dinner, so I took a short break. Her dream was to be a lovely wife, so she happily grabbed the serving spoon when I asked for seconds.

After offering to do the dishes, I moved to the sink, grabbed a sponge, and spoke to the smartphone I had set on the stainless steel countertop.

"Maxwell."

"Sure."

"What happened with the test viruses you sent to the TV station and the luxury hotel?"

"I sent 49 types of harmless malware to the stages for the first two rounds via 159 different routes, but not one was successful. I believe the Bright Cross's data is being protected with precision surpa.s.sing my own. An engineer working by hand could not intercept them at this speed."

"Which means…"

"Sure. Even with the thick lines out of the city cut, the simulator is still in effect. The simulator itself is likely somewhere inside the city."

What a pain.

That was the Bright Cross for you. They sent everything in the worst possible direction and refused to make anything easy for me.

"Maxwell. If the Bright Cross has a supercomputer somewhere in the city, could it be at a public agency?"

"No. A public agency's supercomputer is cla.s.sified as a public works tool, so they are constantly monitored by citizen's groups and ombudsmen and the project as a whole must be made public. That does not suit the needs of illegal calculations like the Bright Cross's."

"So they aren't borrowing a supercomputer at a national university or research inst.i.tute."

"They could be using a general corporation, a private university, or an unregistered device such as myself. Owning a supercomputer is not restricted by law."

There was the Electric Utility Law and other related laws, though.

Hm.

"What does a supercomputer-level machine need?"

"Sure. This will include a wide range of topics. First, the machine itself has a lot of ma.s.s, so it would break through the floor of a normal apartment. It cannot be powered with a normal residential power source and it would also need a cooling system on the level of a cold-storage warehouse. It needs an environment with clean air void of dust and dirt, all static electricity must be eliminated, lightning strikes and power surges must be guarded against, and shaking and tilting are also off limits. And in addition to shaking and impacts from outside, there must also be a countermeasure against the noise and vibration of the machine itself. After all, dozens if not hundreds of large computers will be hooked up in parallel, so dust could pile up quite high and they could even produce a resonance based on their natural frequency. Also, to receive and transmit so much data, they must inform the ISP or have their data capped. Even if you only built a container-sized handmade machine, wouldn't you know all this better than me?"

"It's like your own smell. You don't notice it yourself."

In that case, I had to start by searching for a location that fit those conditions.

Once I had a list of suspicious supercomputers, I would begin another cyber attack against the facilities connected to the Bright Cross. The machine that sent and received a bunch of data at that moment would be the Bright Cross supercomputer being used for defense.

"What should I do about the thick lines out of the city?" asked Maxwell.

"Leave them cut if possible. The machine is probably in the city, but it would be a pain if they tried something from outside the city as a diversion. I want to keep those lines cut until we've located it."

"I cannot guarantee it."

"Just do what you can."

Either way, we had no time.

The Five Battles Precipice. The demon of statistics. We only had the 3rd and 4th rounds left to figure this out and the opponent for the 3rd had already been announced. I doubted they were going to drag this out for 6 months or a year. They would want to use the advantage they gained by Itou Helen's damage. More importantly, the Bright Cross had to be p.i.s.sed after having an Archenemy get the better of them twice in a row. They had not managed to execute even one Archenemy with this new system after pulling out from their underground facility, so that was hardly surprising. That was why they wanted to end this quickly. They hated to see hope form that Itou Helen might just survive the Colosseum.

"We are going to be busy," said Maxwell.

"Yeah, this is just like summer homework. You always wish you could buy some more time in the end. But real life isn't like a game with in-app purchases."

Lots of electricity, a cooling system, unlimited data, a foundation that could support the weight, dust and dirt protection, static electricity protection, lightning and power outage protection, shaking and vibration protection…

A supercomputer needed a lot of things, but I decided to start with the easy ones.

I gave Maxwell instructions after finis.h.i.+ng my bath.

"Let's start by checking the records of the power companies and communication companies."

"Sure."

"I doubt they just described it as a secret supercomputer, but check for any suspicious projects that fit the scope."

"Understood."

The power business had grown a lot more diversified lately because they were trying to separate the production of power from the distribution of power. There were probably a lot of places to check, but Maxwell came in handy because he never got tired.

…And since I could only sit around and wait, I mentally went over everything I had to do.

The most obvious ones were the records of power and data usage.

But that wasn't actually the most important part.

"The cooling system…I guess."

Simply gathering a bunch of computers and hooking them together in parallel was not that difficult. That was no different from a school's computer lab or the computer cla.s.sroom in a multi-tenant building near the train station. A power strip could secure the power, a hub could handle the LAN cables, and then you just had to change some of the shared settings. The only other question was how large you were going to make it.

But the cooling system was a different matter.

A normal computer used air cooling. In other words, it had a small fan. Lately, there were some that used liquid cooling where water was pa.s.sed through tubes, but those 2 were the only real options.

A largescale supercomputer would use an industrial air conditioner or something like liquid nitrogen or helium. Basically, a chemical coolant was used to keep the entire huge building below freezing, just like a cold-storage warehouse at the harbor.

Liquid cooling was just barely enough for my Maxwell since he fit in a single container, but I used some pretty powerful pumps to keep all the water circulating through the long tubes that snaked all over the place.

Liquid cooling wouldn't cut it with anything larger than that. The Bright Cross's simulator was better than Maxwell, so they likely used something like a cold-storage warehouse. Otherwise they would need water and pumps on the scale of an aquarium.

No matter how they disguised the rest, they could not hide the cooling system.

The Bright Cross had to have the machine somewhere with lots of coolant. But what exactly would it be? Was it really in a harbor cold-storage warehouse or a cargo s.h.i.+p for fruit? If they were cooling something the size of a gym to below freezing, there were only so many possible locations, so why couldn't I see where it was?

"Onii-chaaan."

Then Ayumi called out to me while lazily watching TV in the living room.

"Onee-chan says she forgot something. Did you already take a bath? Then you'd catch cold, so I guess I'll have to go."

"No, I'll go."

It was true my head was overheating. A nighttime stroll might be perfect as a change of pace. …And day or not, Ayumi wore a jogging outfit not much different from a swimsuit, so I was honestly a little worried for her. Was she letting her guard down because she was a powerful Archenemy?

"What does she need? A textbook?"

"A product a girl needs once a month."

"Bff!?"

I wanted to take back what I said, but I knew that was a lost cause. Still, wasn't having a male family member bring this to you at school about as damaging to a girl as having a female family member check under the bed or look at your internet history for a boy?

"…Well, I'll call it a win since I get to see her blush. That's pretty rare!"

"Onii-chan, you're sometimes the worst."

"I'll be going!"

I took the cute pouch from Ayumi and left.

At night, the way to school felt different than normal.

This was the world in which Erika lived.

I pedaled the collapsible bike while conversing with the smartphone stuck in the GPS device holder.

"I have a report. The ISPs did not turn up much. Including schools, hospitals, and corporate buildings, facilities containing dozens or even hundreds of computers can be found everywhere."

"Hospitals? I always pictured them as wanting you to keep cellphones and computers out."

"Most modern medical devices are connected to a hospital intranet and patients' test results are shared. I imagine they wish to eliminate the use of general-use devices because they do not want their equipment to malfunction."

I kind of understood but kind of didn't. If they had that many computers in the hospital, wouldn't they cause malfunctions in each other?

"I discovered requests for a few suspicious projects at the power companies. Here are the details."

I wasn't reckless enough to stare at my smartphone for long periods of time while riding a bike around at night. I waited until I was stopped at a light and then scrolled through the data on the smartphone.

"Is this it? At the ski slope, in the industrial region, and at the zoo…"

"Sure."

It was true that those places had unnaturally increased their power consumption recently. Enough that they could power a whole supercomputer. And the ski slope shouldn't have even been running during the off season.

But I sighed.

Based on this, I would be able to end this conversation before the light changed.

"They're probably all innocent. The industrial region is probably just an extra production line. I remember seeing a factory tour blog complaining that they had tents up for some remodeling."

"But based on my research, there has been no change to the production count."

"Then they're probably doing a test run."

Next was the zoo.

"This would be for heating. When raising animals that are susceptible to the cold, you have to heat their cages all night long. The cold has been coming back recently. If the weather data matches perfectly with the power consumption, then they're innocent."

"Then would it be the ski slope? They would not need to use power during the off season."

"That would certainly make this simple. But…"

"But?"

It came back to the cooling issue. On a snowless ski slope, they would have no way of fighting the supercomputer's heat. I doubted they were making full use of the artificial snow machines. Plus, that wouldn't be nearly enough to cool it.

"In that case, I wonder if they're running a secret casino during the off season. I've heard ski resorts all over have been struggling."

The light changed.

As I crossed the crosswalk, I belatedly realized that the light apparently didn't play its melody at night. That made sense to not cause a nuisance, but what would the people with poor eyesight do?

"In that case," said Maxwell. "Where is the Bright Cross's simulator?"

"It simply isn't possible to build a supercomputer on that scale without leaving any kind of trace. If it's in the city, there have to be hints."

I arrived at the school without finding an answer. Schools were generally frightening at night, but ours was full of people thanks to the nocturnal division. Around half the windows were lit. With that much light, a ghost would have a hard time making an appearance. …And knowing a vampire studied here through the night helped to soften the occult fear.

When I called Erika's phone to tell her I was there, she arrived in the hall trembling. It was truly rare to see her face that bright a shade of red.

"A-A-Ayumi-chaaaaaaaan!!"

"But, Erika, if it's just this once, couldn't you have stopped by a 24-hour convenience store or discount store?"

"And I'm an idiot too!!"

She really did cover her face with her hands and curl up by the wall.

To be honest, it was cute.

And when I looked down from above, I could see her red bra showing through the blouse visible at the chest of her blazer.

"Sob. Now, Satori-kun, be careful on the way back home…"

"Sure thing."

With that, I left Erika. She had been in cla.s.s, so she had to get back.

And as I walked toward the entranceway, I glanced out the hallway window.

I saw a large pool full of dark water. I had said the school wasn't scary at night, but that area was a different matter. I guess it was frightening how the dark colors of the night kept me from seeing the bottom. At any rate, the pool looked a lot different than during the day.

I started to look away…but then I stopped walking. I looked to the pool again.

Something bothered me.

Yes. That's' right.

Maxwell had said he could not narrow down the possible location of the supercomputer using the data usage requirement. He had said that schools, hospitals, and corporate buildings all had dozens or hundreds of computers linked to the outside through a server.

"Ah."

And hadn't I said that a computer above a certain size needed more than air or liquid cooling? Hadn't I said they would need an industrial air conditioner or chemical cooling using liquid nitrogen or helium in order to keep a gym-sized s.p.a.ce cold?

Hadn't I said the only other option would be water and pumps on the scale of an aquarium?

An aquarium.

A giant pool.

"Ahh!?" I shouted without thinking.

Didn't this fit? And I saw it every day! The answer had been right in front of my eyes!!

"Maxwell! Check every school in Kukyou City. It can be elementary, middle, or high school, as long as it meets the data usage requirement! Give me a list of every one that uses enough power for a supercomputer! And this high school should be on that list. With the normal cla.s.ses and the nocturnal cla.s.ses, it should look like it's using twice as much power. And the power usage should be the same at all times due to having cla.s.ses day and night. It won't look unnatural if it's using power at night. And the school is still running on days off because of club activities. So…!!"

At that moment, another electronic tone rang from my smartphone.

It was a video chat from…Blue Bunny Girl Karen!?

"Pin pon pon poooon! Do you know what this means? The Colosseum's 3rd round is about to begin! Everyone involved should head to the special stage indicated on the attached map. It's a live broadcast, so we will be quite strict about the time. If you're even a second late, you won't be let in. Bye!!"

"Dammit!"

This was the worst possible timing. Yes, almost as if they had calculated it!

"What will you do?" asked Maxwell. "It is possible your advice as her second will not be of much use unless you destroy the Bright Cross's simulator. You could always choose to keep your focus on the search of the simulator."

Would I choose Muramatsu Yukie the Dark Elf?

Or would I choose the Bright Cross's simulator?

Which one should I focus on!?

"…Let's get to the Colosseum."

"User."

"Don't lose sight of what matters here, Maxwell. Our goal is rescuing Itou Helen. Destroying the Bright Cross is only a means to an end. We can't get that backwards."

Yes, sacrificing Itou Helen to destroy the Bright Cross would be meaningless.

With that decided, I had to get to the special stage.

The Bright Cross would not want to let Itou Helen's victories continue. Before, they had been fine with either outcome as long as one side died, but now they would likely focus on crus.h.i.+ng Itou Helen in particular.

That meant a simulator more powerful than ours would be fully supporting the dark elf.

This time, it would go beyond a battle between two Archenemies, witch and dark elf. A battle between simulators would be underway in the background.

To be honest, I didn't think I could win in a direct battle. But I couldn't leave Itou Helen alone. She was already injured, we had almost no data on this Archenemy, and the enemy would be secretly supported by a simulator. I doubted she could overcome that on her own.

"Let's go, Maxwell."

"Sure."

"Let's defeat that dark elf and save her in the process. Save her from that G.o.dd.a.m.n Colosseum!"

Power Usage: 70.4%

Cooling Efficiency: 58.8%

Processing s.p.a.ce Usage: 75.9%

Temporary Memory Usage: 68.5%

Unusable Memory: 2.3%

Data Loss within Cables: 0.00000000002%

Vibration Detection: Within acceptable bounds

Dust Detection: Within acceptable bounds

Backup Power: Functioning Normally (1, 2, 3)

Lightning Cutoff System: Functioning Normally

Running Tasks: 45

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Manual command from official administrator detected. Creating new task. Please input task name and processing priority level.

Task Name: Colosseum Damage Control

Processing Priority Level: Maximum

Task creation complete. Beginning calculations.