Chapter 59: Mutual Threats

"About... the Arius Branch School?"

"That reaction—so you did know after all."

"…!"

Sensei quickly shut his mouth, as if realizing he’d slipped.

"It’s fine. I hadn’t mentioned it earlier because I didn’t want to stir up any unnecessary sympathy... but I figured someone like Mika would end up leaking information anyway."

Though, as it turned out, that wasn’t the case.
I’d already probed Mika several times since then, but there was no sign she’d contacted Sensei outside my supervision. Even the Intelligence Department reported nothing.

In other words, Mika truly hadn’t spoken with him—an unusually restrained move for her.

So then… who told Sensei about Arius Branch School?

"Sensei. Did you come into contact with the ‘traitor’?"

"…"

"Let me be clear, to avoid any misunderstanding. Are you aware of the ‘Trinity traitor’s’ identity—and did you conceal that from me? Or worse, have you been swayed by them?"

In other words, Nagisa was probing to see if Sensei had met with the so-called “Trinity traitor,” gathered information, and perhaps even conspired with them.

The identity of that traitor—according to Asiri and Mayumi—was Shirasu Azusa.
But there was no proof, and Azusa herself had never once mentioned Arius Branch School by name.

"I… don’t know yet."

Sensei did feel sympathy toward Arius Branch School. He also cared deeply for Azusa.
But that didn’t mean he condoned attacks on Trinity or the destruction of the Eden Treaty. To him, that was an entirely separate matter.

"Then who told you about Arius Branch School?"

"I can’t say. You’d only end up suspecting that person, wouldn’t you, Nagisa?"

"I see. Then that’s fine."

Nagisa returned a polite, fixed smile—one that was clearly forced.

Anyone who knew about Arius Branch School yet lay outside her awareness… was suspicious by default.
Leaving them unchecked would’ve been the truly foolish choice.

"Well, I have a few leads. Even without your cooperation, I’ll find out soon enough."

"Nagisa... please, listen to me. I have no intention of being your enemy."

"…"

"You’ve thought long and hard about this, haven’t you? You’ve struggled, and this is the path you chose—along with the resolve to bear it. But still…"

Sensei couldn’t finish. Not because he couldn’t find the words—
but because he saw Nagisa’s face.

It wasn’t the same expression she’d worn before—the rigid smile she used to preserve Trinity’s order like an iron mask.

"Sensei..."

"…!"

It was the first time Nagisa had spoken with such emotion.

"How much do you actually know about Arius Branch School?"

"…"

But the tone soon faded.

"Nagisa…"

"Please answer."

"I heard… it was a school that was persecuted when Trinity was first founded."

Pressed by Nagisa’s intensity, Sensei couldn’t ask anything in return.
The only thing he was sure of… was how frail Nagisa looked in that moment.

"Are you aware of what happened last year?"

Last year… he recalled what Mayumi had told him.

"I heard Trinity was attacked… and…"

"And?"

"Just a rumor, but… apparently the culprit was Arius Branch School. A girl named Seia was seriously injured."

"I see."

Nagisa let out a deep sigh—part exasperation, part relief.

So, Sensei didn’t know the truth.
He hadn’t grasped the real danger of Arius Branch School. That, at least, explained his earlier attitude.

"Seia was indeed attacked. But the reality is far worse than you think."

"The reality…?"

"Seia was killed—by a member of Arius Branch School."

"…What?"

"They used some kind of special method. After all, the only sound heard from Seia’s room that night was a single explosion."

Sensei blinked, doubting his ears.
Here in Kivotos, for students who possess halos, the concept of “death” is almost unimaginable.

But it wasn’t as if he didn’t understand what that could mean.

—Ten years ago, during the civil war… there had been casualties. There were people whose halos had been literally destroyed.

"Ah…"

It clicked.
Arius Branch School—and the notion of “death”—finally connected in his mind.

"You remembered something?"

"…"

"Well, there’s no need to answer. It’s better if you haven’t. But now you understand, don’t you? Just how dangerous Arius Branch School is."

"…!"

He understood all too well.
If what Nagisa said was true, then it was no wonder she was so desperate to find Trinity’s traitor—anything less would’ve made no sense.

"And that’s not the worst of it. I’m talking about their combat strength."

"Combat strength…?"

"At the time, we assumed they were just a small group."

As she spoke, Nagisa recalled the reports from a year ago.

"And that assumption wasn’t entirely wrong. With Trinity’s full force, they could’ve been easily suppressed. The problem was… their individual strength."

"Individual strength…?"

That night—those monsters from Arius Branch School who displayed power beyond nightmares.

"Even Mika, who rivals the Chair of the Justice Realization Committee, could only hold them off for a short while with several allies. Those people… must have undergone some kind of special training."

"That strong…?"

It was a shocking story even for Sensei.
Still, compared to the idea of actual deaths, it didn’t seem quite as threatening.

"It would’ve been fine if that were all. We could’ve overwhelmed them with numbers. But…"

"…"

"Among them was someone whose power rivaled even Tsurugi’s."

"…!"

"Do you understand now, Sensei? Just how great this threat is?"

A method capable of killing students. Alone, it might have been countered by a powerful enough student.
But if you add someone as strong as Trinity’s top fighter into the mix…?

The implications were terrifying.

"That single student defeated most of the Justice Realization Committee members sent to intercept them, temporarily neutralized Tsurugi herself, and even forced Hanekawa Hasumi to retreat."

Nagisa recited the report as if retracing the shock she’d felt that day.
That shock had left her utterly convinced—the attackers were from Arius Branch School. If it had been any other academy, they would’ve been identified immediately.

The fact that they weren’t meant only one thing: the enemy was Arius Branch School.
Not that this realization brought Nagisa any comfort.

"And after facing Mika, they escaped. Since then… there’s been no sign of them."

Nagisa’s eyes hardened as she stared directly at Sensei.

"…A white coat, and equally white hair. Short in stature, wearing a black mask, with their equipment concealed beneath their clothes. They reportedly used ropes braided from hair, moved with explosives, and attacked with a shotgun. Because of that appearance and ability, some have even called them 『the White Devil of Arius』… Does that ring any bells?"

"…Could it be… Azusa?"

"……"

Nagisa’s silence was answer enough. Sensei fell into thought, then slowly shook his head. No—that couldn’t be right.

Azusa’s fighting style relied on guerrilla tactics with an assault rifle. The short stature and white hair matched, but the mask she wore was a gas mask, not a black one.
As for “moving around with bombs,” that had only happened once—when she was cornered by the Justice Realization Committee. And if she truly possessed that level of strength, she never would’ve been cornered in the first place.

"…At the very least, I don’t think it’s her."

"…Are you sure?"

"Yeah. I swear I’m not lying. I’ve seen her up close, and there are clear differences. I’m convinced they’re completely different people."

"…Then, during the recent incident—the Second Special Academic Exam—did you see anyone resembling that individual?"

Sensei shook his head. Nagisa studied his face closely, but he didn’t seem to be lying.
She didn’t believe him completely, yet there was no reason to keep pressing. She forced herself to cast aside the suspicion clouding her mind.

"…Then you understand now, don’t you? The extremely dangerous situation Trinity is facing."

"…Yeah."

"I owe you an apology for not speaking to you sooner, Sensei. But I needed time—to see things clearly for myself."

Though distrust still lingered in her heart, Nagisa extended her hand toward him, palm up, trying not to let that feeling show.

"I… we don’t want to lose anyone—or anything—ever again…"

And as she whispered that small fragment of truth, her voice softened.

"Sensei, please. For the sake of all the students who live within Trinity… take my hand, and lend us your strength once more."

"……"

Sensei hesitated. Deeply. From the bottom of his heart.

If he took Nagisa’s hand now, it would mean turning against the Remedial Class—perhaps even driving them toward expulsion.
But if he didn’t… innocent students might die.

As a Sensei. As an adult. What could he do? What should he do?

"…Nagisa."

He had his answer now. The decision was made.

"I…"

"…!"

Nagisa’s eyes wavered. He held her gaze, ready to speak his resolve—

"—!? What was that sound?"

BOOM!
The thunderous explosion and the shockwave that followed drowned out his words completely.

Nagisa’s mind raced.
The explosion had come from this building. If so, further blasts could cause a collapse. An attack by Arius Branch was highly possible. In that case, the optimal course of action was clear.

"Contact the Justice Realization Committee! Sensei, it’s dangerous here! You need to evacuate immediately!"

"R-right!"

At Nagisa’s sharp command, the tension between them vanished. Sensei flung the door open.

They ran.
And after covering some distance—

"…That sound… someone’s fighting?"

"Yes. And judging from the impact… two extremely powerful individuals."

In an instant, Nagisa reached a single conclusion.
She didn’t know the details, but there were only a handful of people capable of producing such devastation—and standing against it head-on.

"The White Devil of Arius…!? M-Mika!!"

"Hey, Suou-chan. Mind if we talk for a bit?"

"—!! Wh… why…!?"

Why… why is Mika here…!?

"What do you mean why—oh, you mean the 'contract'? You did say not to act on my own, didn’t you, Suou-chan?"

There’s no hostility or anger in her tone.
It’s not because Seia was hurt, or because she lost her temper in the moment.

More than anything, that timing, that explosion—Mika’s actions were clearly deliberate.

"But you also said this, right? 'If your physical or social safety is at risk, you must prioritize your own protection.'"

"…!!"

"If everyone thought Nagisa was dead, my position would be in danger, right? So attacking you here counts as self-defense—prioritizing my own safety."

"That’s not it…!!"

"…?"

No. That’s not what I wanted to ask.

"Why… did you attack me…!? To take that!?"

"Ah—so that’s what you meant."

Why does she look so calm, so casual…
Like she’s just realized something obvious.

She’s taking the bomb—the one meant to destroy the Halo, the one we were told to use to kill Nagisa.

"Hey, Suou-chan. Do you remember what happened last year?"

"L… last year…?"

Does she mean Seia’s assault?
But no, Mika accepted that I didn’t kill her—

"Back then, do you remember what you did to convince me?"

"I…"

…The bomb to destroy the Halo.
I tried to blow myself up with it.

"If I hadn’t stopped you, you really would’ve done it, wouldn’t you? Even though you could’ve died."

"…!!"

"And that wasn’t the only time. That was just the start. I’ve been watching you all this time—this whole year, Suou-chan. Every move, every moment."

…To think she’s been watching me all this time.
I never noticed.

"You were careful, you always thought things through… but more than that, you were reckless. You never cared what happened to yourself.
I even heard about your plan—to send the kids to the Shanhaijing and then flee to the Abydos District, right?"

"…"

"I don’t think it’s a bad plan. I’ll help as much as I can. But… it’s risky, isn’t it?"

"…!!"

How… how did she find out!?

"The pursuers from the Arius Branch. And if you really intend to violate the Eden Treaty even once… the Valkyrie Police Bureau will come after you.
You know better than anyone how powerful those two are."

This is completely beyond what I anticipated—far beyond my calculations.

This girl has thought it all through. Considered it, predicted it, foreseen it…!

"And the Shanhaijing kids aren’t completely safe either. Everyone knows the risks. Everyone’s accepted that.
But still, I just can’t believe you’d go through with it… hey, Suou-chan."

…Ah, I see now. I’ve done it again.

"…Suou-chan, what were you planning to do?"

"W-what are you… talking about…?"

"You were planning to sacrifice yourself to save everyone else, weren’t you?"

"…!!"

Again. My thinking, my assumptions, my predictions—all wrong.
I miscalculated… I failed again.

"Well, maybe I was wrong—but judging by that reaction, I wasn’t.
So from here on, let me handle it."

"…What do you mean?"

"I mean everyone’s getting rounded up together. We’ll all sit tight in a Trinity cell for a while!"

"!!"

She’s coming. No time for regret or guilt—those can wait.

Getting captured… fine. I’d already considered that possibility.
But the timing’s bad. There’s only a little time left before I’m supposed to meet with the others.
I need to send a message—make sure they get away…!

"Hah—!!"

"…A smoke screen, huh?"

To do that, I need to escape… even if just for a moment…!

"Hey, Suou-chan."

"Ugh…!!"

…But even that seems impossible right now.

"Under normal circumstances, escaping from me might be easy for you, Suou-chan."

"…!!"

"But do you really think you can run in this situation?"

It’s far too threatening. Far too overwhelming… Misono Mika—this wall…!!

"…Squad leader’s late, huh."

"Yeah. I’m starting to get a little worried."

In a quiet spot on the outskirts of Trinity—far from the crowds—the Eighth Squad had gathered together to secure an escape route.

"That idiot’s not someone who can be taken down easily. No need to worry too much."

"…Well, that’s true. Not that I’m worried or anything."

Saori gave a faint smile at Misaki’s usual cold tone, but her expression faltered as a thought crossed her mind.

"That explosion… that sound just now…"

"I-it was pretty loud, wasn’t it…?"

"Yeah. Way too loud."

But was that sound really just a bomb?
Suou could’ve easily caused something of that scale, but would she have done it without a reason?

Before anyone could dwell on it further, another sound cut through the silence—smaller this time, yet still heavy and unmistakable.

"…!! Hey, that just now…!"

"Yeah… no doubt about it…!!"

It wasn’t an explosion this time. It was the sound of walls breaking, the ground being torn apart.

A sound they’d been forced to hear far too many times last year.

"Misono Mika… she’s fighting…?"

"Hey… could it be…?"

A small, cautious seed of unease began to sprout in every member of the Eighth Squad.

"Suou…?"

The thought of her flashed across their minds—a dangerous, yet strangely gentle and dependable madwoman.
For her sake, their feet began to move on instinct.