The ringing of the alarm clock pounded on my head.

Surprisingly, I had made it to the morning. I had not gone to that flooded battlefield. I had taken a bath the day before and not left the bed since, so I simply had not had a chance to touch enough water to take me to that glowing ocean.

Given what had already happened, either the Leviathan or the Siren intended to use their ticket for each day. That suggested they could not store up tickets and then use them all at once. So I could not let my guard down. Somewhere today, they would make an attempt before midnight arrived. Even if that meant using people infected by parasites like the time before last.

"Good morning, Satori-chan."

"Yeah, good morning."

My mom apparently didn't eat breakfast, so there was nothing prepared. I was kind of used to that now, so I opened the kitchen fridge and found a fish sausage to eat. It was a complete mystery what kind of life Himatsuri-san lived, but since I had school, I changed into my uniform and left the high-rise apartment building.

While walking outside, my smartphone vibrated in my pocket.

"Helen> Senpai, I am following the plan."

After reading the short-message SNS speech bubble, I typed in a quick response and put the phone back in my pocket.

I walked to school like normal.

At the very least, I couldn't see any suspicious infected people around. But after seeing Tanabe-san at the aquarium, I knew they could blend in so perfectly it was impossible to tell.

…And there was no sign of the supposed Siren.

Once I arrived at school, my smartphone vibrated again.

"Helen> I didn't see anyone tailing you."

"…Hm."

I had asked Itou Helen to walk a bit behind me to see if anyone was following me.

"Maxwell, is there a drone flying above us?"

"No. I cannot detect any control signals. It is possible for them to use an autonomous flight program, but they would still need to send and receive signals for error correction, similar to a radio clock. There was no sign of that."

"What about a satellite?"

"I cannot account for unregistered guerilla satellites, but I detected nothing of note. 39 weather, military, and civilian topographical survey satellites pa.s.sed by overhead, but they were all performing a general scan and showed no sign of focusing in on a specific individual."

…I was doing some pretty impressive things here, but sadly I couldn't brag about it when I was only asking Maxwell to do it for me.

Regardless, it seemed they were not using a camera instead of appearing in person.

While I changed into my indoor shoes at the shoe lockers, Itou Helen caught up and spoke to me directly.

"What is this about, Senpai?"

"That's the thing…"

I had explained the details to her when I asked for help, so I didn't need to hold back with her.

"If the Leviathan is to be believed, the Siren would be targeting me, right?"

"Well, yes…"

"So I was wondering how she would be targeting and attacking me. The Leviathan is inside an aquarium tank here in reality, so I thought the Siren might be in Kukyou City pursuing me like an a.s.sa.s.sin or sniper."

"And you didn't find anything. Then was that shark lying about there being a Siren?"

"That would certainly simplify matters, but I have no guarantee of that…"

Finding something was a simple way of proving something, but not finding something did not prove anything one way or the other. Was there no Siren, or was she simply doing something else at the moment? I had no way of knowing.

And there was one other thing:

"It's also possible there is a Siren, but she isn't carefully targeting me like that. Her song might envelop all of Kukyou City. That would be the worst possibility."

To be blunt, that was my biggest concern. Even that Leviathan had talked about intervening, so (if this Siren really did exist) the Siren's ability had to be greater than one of the seven deadly sins…

I didn't know the exact conditions, but in the worst case, she would be able to send hundreds of thousands of people to that glowing ocean on a rainy day. a.s.suming there was no limit to the number of people she could send at once.

"What I really want to find is that the Siren exists and there are some really intricate conditions that need to be true before she can send someone to that glowing ocean."

That would mean she had to constantly tail me to track my location in preparation to send me to that ocean. In that case, I could move in and achieve checkmate before her preparations were complete. If I lured her into the shopping district with all its security cameras, I could use Maxwell's power to its fullest and work out the Siren's location.

But things changed if she could be anywhere in Kukyou City…or if her contamination could affect such a wide area from outside the city. Then I would be unilaterally tormented to death while trembling in fear of a ghost that may or may not even exist.

Yes, just like before.

It would actually be a relief to learn this was all a lie by the Leviathan, but I didn't have enough information to say that. The Siren was not here now, but that was no guarantee she would not be a minute from now.

I parted ways with my cute undercla.s.sman and entered my cla.s.sroom.

"Satori-kun."

There I found my forehead gla.s.ses Cla.s.s Rep standing tall with her hands on her hips and her cheeks puffed out. She was as blatantly upset as Ayumi when Erika stole the popsicle she had been looking forward to after her bath.

"Come here a moment. Sit. On the floor. Now!!"

"In the middle of the cla.s.sroom!?"

That command came with a high difficulty level, but it was also a wonderfully unparalleled chance to demonstrate my superiority to the cla.s.s. I would gladly take her up on her offer and enjoy every moment of it. Heh heh heh. Hands off, boys and lesbians. Only I can keep up with this Cla.s.s Rep!!

"The depressed aura coming from your house is getting intense. There are tons of black cats out front and the roof is covered in crows and bats."

"…I get the feeling you aren't joking and my stepmom and Erika really are attracting those things…"

"It's because you ran away! And running away from home!? You're just wandering around without the courage to confront them or the resolve to support yourself. Do you seriously think that makes me you look cool!?"

B-bgfhh…!?

I shouldn't have gotten carried away. That was the Cla.s.s Rep for you. It had taken me several days of risking my life to reach that answer, but she sent it at me in like half a minute!! Have you ever had your crush stamp your forehead with the words "Hopelessly Smelly Idiot"!? It makes you feel dizzy and nauseous!!

"P-pant, gasp, gasp."

"No hyperventilating. I'm not done yet. I saw Mrs. Yurina crying. She stepped out the kitchen back door and then broke down where she thought no one could see her, but I could see it from my window. Whatever justice you might think you have, whatever problem you might be dealing with, and however the world might work, I am going to cut you down to size here. Got that, Satori-kun? Here goes."

Ahhhhh.

It was over. No one could stand up to the Cla.s.s Rep when she felt a responsibility to do something like this. There was a reason the Cla.s.s Rep was known as the Cla.s.s Rep.

"You can fight with your family. You're human, so of course you're going to have differences of opinion and issues you can't back down from. But, Satori-kun, why would you leave instead of speaking with them!? Did you not realize all you've done is take any other possibility away from them, given up on them, and sealed the issue away!? I know you did. I know you had to have known what you were doing. You know first-hand how painful it is to be treated like that!!"

The Cla.s.s Rep had seen it all.

She had seen my family situation from a far calmer perspective than anyone involved. And that was why her words stabbed into me so sharply. Even if the rest of the cla.s.s did not understand, those words pierced my chest more than any others could.

A family had come to an end when my mom left the home.

There would have been a mixture of feelings behind that decision, but that had been the end regardless. We had fallen apart.

The Cla.s.s Rep had seen that.

She had seen me lying around like a broken doll after I lost everything.

That was why she was angry.

She was too angry to care who saw this.

Someone who knew that pain was forcing it onto someone else. And onto people he had decided were his family.

I could only listen in silence.

How could I object? What could I do besides remain seated on the floor and hear her out?

"Don't rely on others and don't just a.s.sume someone else will work this out!! Satori-kun, you should know that what you take for granted and what you believe will continue forever can fall apart and collapse far too easily. So don't rely on others here!! You have to think about what a single mistake can cause and live a life that works to avoid that mistake. Isn't that all you can do!?"

I wished she would just hit me.

That would have been far easier to handle.

But the Cla.s.s Rep seemed to read my mind when she looked me in the eye. She breathed from her nose and responded.

"No. That isn't my job. So go settle this for yourself, Satori-kun!!"

Regardless, it must have been confusing for the rest of our cla.s.s. But I didn't really want them all getting into my family life, so that was fine with me.

They made a lot of speculation, but in the end it was summed with the following exchange:

"Well, Amatsu and the Cla.s.s Rep are always like that."

"She's been scolding him since elementary school, hasn't she?"

I was glad for that.

Afterschool, everything was dyed in an orange light.

"What? Do I need to follow you?"

The Cla.s.s Rep was still angry, so I parted ways with her and looked up at a house. It was the one next door to my Cla.s.s Rep childhood friend.

In other words, my house.

…I couldn't believe it. It was my house, but I wasn't ready for this. Besides, if I suddenly disappeared from the high-rise apartment building, I would worry my mom and Himatsuri-san this time.

I looked to the intercom…but it would be weird for me to use that. Given the day of the week, my stepmom would not be standing at a register for her part-time job or at her mom's club. Amatsu Yurina was there. I didn't need to call first to check.

The Cla.s.s Rep really was watching.

At this point, I would have to face my stepmom.

"…I-I'm home."

I hesitantly opened the front door and called out.

And something seemed intensely off from the moment I did so.

…What was this smell?

Rusty wasn't quite right. It was like something was rotting…except no, that wasn't it either. At the very least, it wasn't something that should be coming from a home.

"Mom…?"

Perhaps I should have turned back.

But without thinking, I slowly stepped inside. Something formless and unknown was encroaching on my territory. That was what it felt like.

It felt more cramped than Amatsu Taori's luxury apartment, but no part of that house would make you feel lonely.

The entranceway was dyed orange by the setting sun.

There was something on the floor.

Finally.

Only now did I manage to place the smell. It was an encroaching symbol. An unpleasant stench that should not have been found in a normal home.

It was a salty smell.

The smell of seawater that had gathered in the rocks and rotted.

"Mom!!"

I finally managed to focus properly on the object lying in the middle of the entranceway. It was Amatsu Yurina. The long hair tied back and her tight blouse and jeans were all soaked with sinister seawater. She curled up in something like a crawling position and she trembled while holding her stomach.

But when I started to run over, she unsteadily moved her arm to hold her open palm out toward me.

That hand wet, with a dark red liquid, told me stay back.

"…Satori, have you used up your one-way ticket for the day?"

"If not, then stay away. Step on the puddle and you'll be dragged to the other side…"

What did this mean?

That was obvious, you idiot!!

Whether it was the Leviathan or the Siren, they could bring more than one person to that battlefield. That was obvious from the fact that Himatsuri-san and I had been fleeing together.

It wasn't just us.

While I had been desperately trying to save myself, there had been someone else caught up in it all. While I had run away from home, she had worriedly given me advice over the phone.

It was obvious when I thought about it.

Whoever was behind it, they would be most interested in Archenemy Lilith. So there was always a risk of her being sent directly to that glowing ocean in addition to using me as a hostage!

"But…how? Yes, you're Lilith, a major demon lord, so you should be able to easily defeat a normal Archenemy like a vampire or zombie…"

"Ha…ha ha. You overestimate me. Maybe I scared you too much at that abandoned hospital. Things can change based on compatibility and the specific conditions."

Still curled up on the floor, my stepmom forced a smile. So I wouldn't panic, run over, and step in the puddle.

"But…if you haven't used your one-way ticket yet, then we simply missed each other. I should have returned immediately instead of sticking around. What a basic strategic error. Ta ha ha."

What was this?

Did that mean she could have easily escaped on her own, but she stayed in that dangerous flooded battlefield to search for me in case I was there? While isolated and surrounded by a giant shark, a Siren, parasites, and infected people, she had ignored the dangers to herself and gone around calling my name? And that's why this happened to her…!?

How…

How could I be so stupid!?

Why had I run away from home and felt I couldn't look her in the eye? If I had at least agreed to call home at a set time or otherwise set up a way to let her know if anything had happened to me, she wouldn't have had to search for me in vain!!

The Cla.s.s Rep's words pierced my heart anew.

Family was not an absolute for us. I had seen it shatter before my eyes once before. So I had to live my life while thinking about what a single mistake could cause. We had to respect each other. That was all so true.

What parent could sit idly by knowing their child was occasionally setting foot in a deadly world? Of course she was going to find a way to go there too. And would a parent in the same situation tell their child about it? When doing so would only invite their child to follow them? Of course they would keep it a secret!

I had built a simulator like Maxwell and I couldn't even predict something as simple as this!?

"No, Satori…"

Still curled up and giving off the stench of rotten sweater and blood, my stepmom desperately got the words out.

I could not run over to her or hold my hand to the wound in her stomach.

It was the water.

The great maw of the giant shark or Siren was in the way…!!

"Don't give into emotion. You decided to bring humans and Archenemies together in a different way than the Bright Cross, remember?"

"Kh."

"So you can't. You can't give into the feeling roiling in your chest. That only leads to the same b.l.o.o.d.y path of retribution as the Bright Cross…"

"But…"

Was she telling me to overlook this?

Was I supposed to use my stepmom's blood to get past this? Was she saying that was the right thing to do?

But I had never been trying to do the "right" thing! I just couldn't stand to leaving someone alone when they were crying and I couldn't bear to see blood!! I had wanted to protect Erika and Ayumi and I had wanted to side with Itou Helen the Witch, Muramatsu Yukie the Dark Elf, and the others to stop the Bright Cross's oppression. That was all. That was all it was supposed to be, so how had it ended up like this!? Why was I kept from acting here and forced to overlook the person who had done this to my stepmom!?

"…It's the same…"

My stepmom, Amatsu Yurina, spoke in a trembling voice. I doubted it was just the pain. She was trembling because her injury was threatening to take away her son's dream.

"That same feeling is what created the madness behind the Bright Cross."

…What was I supposed to do?

I doubted the Leviathan or Siren would stop with this. Who would be next? Erika, Ayumi, the Cla.s.s Rep? Did I have any reason to think Itou Helen or Kuroyama Hinoki would be safe? We were up against an Archenemy that only needed to point at someone and register them to drag them into that glowing ocean. Then they would be in that sunken battlefield containing a giant shark, a Siren, parasites, and infected people.

Would I try to talk?

Or would I try to fight?

Either way…

"…Mom. Even as a great demon lord, I can just send you to the hospital like normal, right? You use normal medicine when you get a cold."

"Satori…?"

"Maxwell, call an ambulance. They can only drag down someone who was chosen, so the EMTs should be fine."

My stepmom had to have just returned from that deadly world. She was soaking wet and curled up in the entranceway with a puddle of sweater and blood surrounding her.

There was an "entrance" there.

I still had my one-way ticket. I would find the culprit if I pa.s.sed through there. Whoever it was, that piece of s.h.i.+t had done this to my parent!!

"No, Satori!!"

I did not bother listening to her.

I took a large step.

And for the first time in my life, I chose for myself to step onto that h.e.l.lish battlefield.

Based on the ground level, the glowing ocean's water was 15m deep on average. The residential district full of short houses was entirely flooded. And when starting indoors, it was a lot like a maze.

But there was a difference between being dragged down when you least expected it and diving in yourself. There was no lost time. I swam across the entranceway, through the living room, and out the gla.s.s door that had already broken from the water pressure. From there, I just had to swim straight up in search of oxygen.

Would I make it in time?

I would make sure I did.

More than the oxygen, I was afraid of getting decompression sickness from rapidly swimming up more than 10 meters without diving equipment.

"Bwah!!"

My face broke the choppy surface. The rain was blowing in the wind as usual. The water would be giving off a damp blue glow, but even with thick clouds covering the sky, it was before sunset. Like a lit movie screen, the glow-in-the-dark paint glow was drowned out.

There was no point in fighting the current. I focused only on staying afloat and let the current carry me while pulling out my waterproof smartphone.

"Maxwell, check the situation."

"Sure. The location of the 'today's exit' door is unknown. Nor do I have any information that could act as a hint."

With the blackout caused by the flooding, we could not use the security cameras. Maxwell's vision was almost entirely limited to my smartphone's camera.

So if I couldn't see something, neither could Maxwell. Along the route to the garden, the gla.s.s had been shattered by the water pressure and I hadn't seen any other windows or mirrors.

"But since injured Mrs. Amatsu Yurina had arrived inside the house and the puddle did not stretch outside as if she had crawled inside, it may be quite close by. Yes, for example, one of the doors within the Amatsu house."

If so, swimming out into the current had only distanced me from the exit. But I wasn't afraid. I had to appear on the battlefield if I was to do what I came here to do.

It all came down to whether I could find a starting point in the residential district that was like a giant lake with no land. Whether it was the Leviathan or a Siren, someone here was violent enough to injure Archenemy Lilith too badly to move. I couldn't just float around like this.

Just then…

I saw a ma.s.sive silhouette directly below me. Yes, it was the size of a submarine.

It parted the surface of the water such that I ended up on its back.

The Leviathan!?

"You do not mind if I speak, do you?"

Once that voice sounded directly in my brain, I found myself as motionless as I had been in the aquarium.

"I avoided this before as you would have stopped moving and drowned, but I cannot just watch. And the risk should be reduced like this."

d.a.m.n, I can't move a finger… Even if it isn't trying to attack, this is not fun!

It was incredibly st.u.r.dy despite the powerful wind and surging water. I felt more stable than on a building rooftop.

"I cannot recommend performing a search for the Siren. I have searched all around myself, but I have not found any sign of her."

So that was why.

But there was something else I wanted to know right now.

"You may speak."

"…Did you know?"

"Know what?"

"That my stepmom, Amatsu Yurina, had been setting foot in this s.h.i.+tty ocean to search for me!? Did you know and then hid it from me while I was at the aquarium!?"

"Of course. Who do you think asked me to drive you toward the exit? Of course, I would have done it whether Lilith had asked or not."

Again.

It came down to my stepmom again. I was the only one who didn't know while she was risking her life to protect her stupid son who kept charging headlong into danger!!

"Do not feel bad, boy. No child is aware what their parents do for them. In fact, a parent that did tell their child every little thing they did for them would come off as patronizing."

"This doesn't mean I trust you."

"Nor should you. I have no intention of b.u.t.ting into your familial bonds. I merely wish to keep a promise I made with my old friend Lilith."

…I had discussed this on the phone with my stepmom.

At the time, she had suggested this was a conflict between those standing at the peaks of different deadly sins, but how much of that had been the truth?

If what I had just heard was true, the Leviathan had already been working to drive me toward the exit by the time I first entered this world through the apartment bathtub. Which meant my stepmom, Amatsu Yurina, had already made her request.

The more I saw, the more I realized how small and ugly I was. Both Lilith and the Leviathan operated at another scale altogether.

"So what will you do?"

The Leviathan apparently did not intend to keep me paralyzed while carrying me to the door and forcing me through. The giant shark understood what my stepmom had been feeling, but had no intention of restricting her son's freedom. This demon lord was quite the educator.

"Let me off at a group of buildings. I can't rely on you forever."

"I like the look on your face now, but as I said, the Siren will not be easily found."

"True enough."

There was no way to search everywhere. For one thing, we had no idea how far this field went. Did it only cover Kukyou City? Did it cover the entire world? Or did it extend to the entire universe? The difficulty of a thorough search would change accordingly.

At the same time, I thought the Siren had to be nearby if she did indeed exist. She had to be somewhere in this city. If she was directly attacking me from the other side of the planet, there was nothing at all I could do.

With that in mind…

"There is one place you haven't checked."

"Where exactly is that?"

"Hey. A Siren is an Archenemy like a Mermaid or Lorelei that uses her beauty and singing to lead sailors astray and sink their s.h.i.+ps, right? But instead of having a fish tail for legs, she has large wings. Probably due to a connection with sea birds. In that case, I can see how a lord of the ocean wouldn't find anything."

I wanted to point toward the heavens as I spoke, but unfortunately, I could not move a finger.

So I used my words instead.

"The sky. If she flies up above those thick rainclouds, no one on the surface would ever be able to find her."

Here, things worked differently than in reality.

Normally, if the Siren was flying above the clouds, she would be seen by radar and satellites. There were apparently even precipitation radars that used terrestrial digital broadcast signals. But the flooding and blackout had destroyed all of that communications infrastructure in this blue battlefield, so all that equipment meant nothing.

If you could hide it from the surface, you could distort reality.

The alt.i.tude of the clouds depended on the type, but I could a.s.sume it was between 2000 and 3000 meters. Clouds had weight, so the thick rainclouds full of moisture tended to be lower. Going there myself would require a helicopter or airplane, but the flat airport would be underwater and the equipment was all too specialized for me to use anyway. Kukyou City had the ocean and some mountains, but none of the mountains towered high enough to break through the clouds.

But those were not my only options.

This was the glowing ocean.

It was not the same as reality. If that was how they were doing things, then I would play along. It was time I found a clear answer. If the Siren existed, I would pull her down from the sky. And if I proved she didn't, then the Leviathan was my enemy.

"This is good enough. Let me off here."

"But…"

"Let me move again."

The Leviathan's voice stopped. At the same time, I could move my arms and legs like I wanted. Its giant body was stable despite the wind and waves, so I did not have much difficulty.

I moved from the giant shark's back to a point partway up a half-flooded building under construction.

I said one last thing.

"I'm hoping you aren't my enemy."

The connection had already been broken, so there was no response. I moved from building to building and the Leviathan dived down into the water.

A social media speech bubble spoke to me on my waterproof smartphone.

"What will you do?"

"I'm about to give you the specific instructions. We're going to smoke out the Siren behind the clouds and bring her down to the earth."

"No. That is not what I was asking about."

I didn't know what it was I wanted to do.

If I was willing to enact vigilante justice on an Archenemy as long as I could justify it with a personal motive, then my stepmom was right: I was no different from the Bright Cross that had been hidden below the city.

At the same time, I did not want to unconditionally submit to anything an Archenemy might try to do to me.

I wanted use to be on equal footing.

I wanted us to all smile together.

That was all I wanted, so why?

"Anyway, if this Siren really does exist, I want to meet her in person. Even if we just need to talk, we can't solve anything if she's looking down on us from the heights."

"Sure."

Now it was time to discuss the actual method.

How was I supposed to bring down the Siren when that Archenemy was flying around at an alt.i.tude of at least 2000 or 3000 meters?

I had no way of flying up above the clouds and I couldn't fire tens of thousands of antiaircraft bullets or surface-to-air missiles to establish a barrage.

But how could I just give up here?

The answer was all around me.

"Maxwell, check the disaster environment simulation map of Kukyou City for the distribution of flammable gases. And I don't mean the city gas inside a maintained underground pipe network. I'm mostly interested in homes and restaurants that use propane tanks. If that isn't enough, check the discount stores and hardware stores. While they won't be as powerful, the small compressed gas cylinders for portable stoves can function as a weapon if you gather enough of them."

"Are you planning to create brutal rockets using thick metal tubes?"

It would certainly be neat if I could do that, but there was no way to ensure their accuracy. In aerial battles, targeting was far more important than power or firing distance. I only had one option since I could not prepare a weapon that linked its radar or IR sensors with the minute movements of its guidance fins.

Instead of targeting a point, I had to cover the entire area.

a.s.suming she was up in the sky, I had to fill every single gap, so she would be hit no matter where in the city she was flying. I could not overlook a single pinpoint.

"I'm going to detonate them across the entire city," I said.

This felt a lot like being in a simulation because nothing I did to this glowing ocean would happen in the real world. I didn't have to worry about destroying it. And thanks to the memories of my fight with Erika, I was getting more and more accustomed to the fear of the surging water.

"Then we ensure an incomplete combustion to send dark smoke all across the sky. With all this water, there should be tons of wet flammable objects…like paper or trees."

"Sure. In other words, you are using chemical warfare."

This was the glowing ocean they had created. They were the ones who had ignored the rules of reality. So it was time I used that supposed advantage against them.

"Now, then. How long can she continue struggling once updrafts created by the heat of the flames fill the dark sky with carbon monoxide?"

I didn't need to be very careful at all.

Whenever I found a gray propane tank, I messed with the hose a bit and set it to explode a few dozen seconds later. There were no firefighters here, so once the fire got started, no one would prevent the entire building from burning. Even the blowing rain and rus.h.i.+ng floodwaters were not enough to put out the fire in the structures rising from the water's surface.

And those giant buildings were made from a great variety of materials, so once the fire spread, it belched black smoke into the sky. The blowing wind was not enough to erase it and it simply spread thinly across everything.

I kept moving on to the next building before the flames and smoke could reach me.

"Maxwell, let's do this building too. Let's check to make sure there isn't anyone inside."

"Sure. Calculating meteorological conditions based on data from the camera and microphone. Updating predicted distribution of carbon monoxide."

When a building didn't already have a propane tank inside, I would throw a small gas cylinder inside like a Molotov c.o.c.ktail. As long as there was no one inside, I didn't need to hold back. I would burn it all, whether it was a broadcast tower or the city hall.

"Next, Building 6."

"Once we're done with that, let's take the rubber boat to another block. We'll cover the entire city with smoke."

When the giant shark was not attacking, I only had to fear the leech-like Remora parasites and the infected people. If the Leviathan was telling the truth, then they would have been the ones who hurt my stepmom. Had an infected person's teeth or nails gotten her, or had a Remora parasite gotten inside her body and she had to forcibly extract it?

But while they had the violence of numbers, they lacked the giant shark's speed. I could lose them if I used a rubber motor boat to travel across the water at nearly 100kph.

"If we're gonna do this, we might as well go all the way."

"Sure. The central financial district's business region is up next, so we will have plenty to choose from."

"Oh, yeah! I always hated those fancy restaurants that always say they're full up from reservations but never actually intended to let you in in the first place!"

We went around a few more blocks, setting more fires.

Thinking back, whoever was behind this had stepped up the attack during the third and fourth days which we fought back-to-back. So what had happened on the second day before that? I didn't even need to check with Maxwell: the Leviathan had gone on a rampage and started a major fire at the industrial complex.

If that had motivated the intensified attacks, then this would work. They didn't want any kind of major fire in the city.

But to settle this, I would need an even large conflagration than that. We had already proven that a fire in a single industrial complex was not enough to bring them down from the heavens.

So it came down to numbers.

If one was not enough, we just had to make even more.

"The density of carbon monoxide in the air is rising. Be mindful of the wind direction."

The black smoke rose into the sky. So would the carbon monoxide riding the updrafts created by the fires. The blowing wind would spread it out, so there would be no gaps once it arrived high in the sky. The black smoke rising from multiple fires grew as thick as a coat of paint and finally transformed the entire sky into a field of death which could not be inhaled.

Things were pretty bad down on the surface, but it had to be even more h.e.l.lish up there.

"If my calculations are correct, the sky is now a danger zone."

"…So it's about time."

The Siren was an Archenemy - an immortal. Since the extreme low temperature and limited oxygen of the sky was her home, she had to be far tougher than humans like us.

But you aren't invincible.

The Leviathan said you Sirens belong to the ocean but live in the sky. That means you can't live a purely aquatic lifestyle. I don't know if a silver bullet or consecrated knight's sword would work on you. But while it might be on a different level, you'll still "suffocate" without air to breathe, just like a human.

So come on down.

Come down from those black-stained heavens and prove it.

Prove you've been sneaking around behind the Leviathan as the true culprit! Prove you're the piece of s.h.i.+t that dragged the entire city into this and harmed my stepmom…my family!!

"Warning."

"Kh."

When Maxwell warned me, my head jerked up to look at the sky instead of my smartphone.

Some kind of golden light broke through the thick black clouds.

No, wait.

It wasn't just falling. It was headed this way!?

"Brace for impact!!" warned Maxwell.

"That won't be enough!!"

I didn't have time to hesitate.

As soon as I jumped out of the rubber boat, the falling golden Archenemy tore through the rubber boat and smashed it to smithereens.

I had fallen into the rapid current.

Without the boat supporting me, I was swept away. That filthy water was full of dangers, like those strange parasites wriggling through it

"Ha ha."

But I still laughed.

I reached for the wall of a building rising from the water and I clung to it.

"I found you, Siren! I've revealed the true villain!! Ha ha ha ha!!"

The Leviathan hadn't been lying. It hadn't been tricking us and hurt my stepmom. That was enough to make me laugh uncontrollably.

And I had brought the real villain down from the heavens.

I had successfully shoved their face into the same waters that had swallowed up everyone else.

Why was it?

I couldn't stop the dark laughter rising from the depths of my gut. I felt so much accomplishment from the filthy action of hurting someone. It felt just like clearing the brutal dungeon in an RPG that appears only after defeating the final boss.

"Warning," said Maxwell. "User, this is no time to be crying. Please stay focused."

Crying? Me???

Wasn't that just the rain? I didn't know what that was about, but I didn't have time to find a mirror and check my face.

She was here.

Archenemy Siren.

The villain behind it all.

She had torn through the rubber boat and plunged into the water, but she had floated back up to the surface. She indeed seemed to have trouble moving in the water. But the sky was filled with the black smoke and carbon monoxide carried there by the updrafts created by the heat of the fires. As a result, she could not go up or down and could only float at the middle area where I could reach her.

This was a rare opportunity.

She was finally in reach. If I did not settle this here, it would be difficult to turn things around again.

And yet…

"Wha-…?"

My eyes widened when I saw the person frozen place as if ignoring gravity and standing on the water's surface.

They had a partially-matured body that seemed on the borderline between girlhood and adulthood. She had some loose white cloth wrapped around her, but there did not seem to be any clear sleeves or hems. She may have been more half-naked than anything.

Her wings were combined with her arms. It would be more accurate to say the long, long blonde hair growing from her head was wrapped around her arms to create a silhouette that resembled golden wings. A Siren was apparently a lot like a Mermaid or Lorelei. This may have been similar to how Kuroyama Hinoki the Mermaid created the shape of a tail fin from her long black hair.

But that was not the issue.

I recognized her.

I also knew that long, long blonde hair from somewhere. It was usually worn up in some kind of cabaret girl style I didn't know the name for, but when let down, it would probably reach past her waist and to her ankles.

I spoke the name of recognition that would not vanish from my mind.

"…Himatsuri…-san…?"

Demons reside in women's hair.

Surprisingly, that legend can be found all around the world. As an example, there is a widely followed ritual of cutting one's hair after heartbreak to purify the hart and bring an end to a bad influence.

On the other hand, it is said evil power resides on a woman's hair after it takes in a demon. As an example of that, there is the Greek legend of Medusa whose long hair became venomous snakes and who became a symbol of something impregnable that cannot be approached from any direction. She is most famous for being a monster with petrifying eyes, but while her eyes could only face forward, the snake hair left her with no blind spots in any direction.

While it is not as extreme, the later legends of Western Witches and Succubi said they seduced men with the power residing in their hair.

…Now, the editorial department of Monthly Chu Chu can't just overlook this! It might seem a little soon, but now's the time to get started! For Halloween this year, I'm definitely using my long hair for a great transformation!! I'll turn myself into a cute witch that would even shock those French n.o.ble ladies who used to place models on their head to turn their hair into something like a diorama. Have faith in Lady Gonzou's feminine power after 30 years of Onee[1] life!!"