The Celestial Observatory

The instant I sensed killing intent, my brain stretched time of its own accord. Through that sticky, endlessly elongating stretch of time, every thought I had rushed past.

Only World Government agents had ever been taught the Killing Style. Outside the Execution Unit and other direct agents, there was no one who even knew how to use this sword.

But why would a World Government agent be at the Vatican? And right before a Gate opened?

No matter how I looked at it, something was wrong. Gate openings were random—natural phenomena beyond humanity's control.

That should have been the case… and yet the other party was waiting at the entrance of the Celestial Observatory as if they already knew something would happen here.

Something was off. That conviction hit me hard.

And so, even after sensing the killing intent, my reaction came a fraction late—late enough to hand them the first move.

"Ugh…!"

Three streaks of light tore in like a beast's claws. There was no room left to keep thinking. I drew my sword in a flash and leveled it toward the depths of the dark.

My whole body like a bow. The sword like an arrow. The vast mana I had raised coiled around the blade in the shape of an arrow. Without hesitation, I drove that gathered power straight down.

A circular shockwave spread outward, and then a pillar of crimson light split the darkness.

The three ferocious slashes shattered, and beyond them the agent was run through by the flash and collapsed. A limp thud—the sound of a life going out—echoed through the dark cavern.

A dog tag stamped with the number 13 clinked as it hit the floor.

"Haa…"

Only then did I let out the breath I'd been holding and look up—toward Clara, who would still be waiting at the entrance of the obelisk.

"Come down! It's safe here for now!"

"H-How, though?!"

"Jump down this way! I'll catch you!"

I poured mana into my sword and drove it into the floor to mark the spot. Through the pitch black, red mana began to burn like a signal flare.

Even so, it was a drop of well over fifty meters.

It looked high even from below, yet Clara leapt into the dark without a moment's hesitation—as if she truly trusted me.

Not wanting to disappoint that trust, I gathered mana in my legs and sprang.

"Hkyah!?"

"Hold on tight, Saintess."

I caught Clara mid-fall and pulled her into my arms. For someone who'd been clinging all day, she seemed embarrassed the moment she was actually held—a cute little sound slipped out of her.

I smiled at her, then gathered wind beneath my feet. The dizzying fall slowed by degrees until, when we reached the ground, I could set us down lightly.

"W-Wow…"

The dizzy freefall. The warm embrace that met her in the middle of it. The mortifying princess-carry. Hit by that triple combo, Clara was still flustered—I left her to recover and drew my sword, scanning the surroundings.

…It really was nothing but darkness.

Even my excellent senses struggled to properly orient. If I fully liberated my brain's functions I could find the way without much trouble, but I didn't want to do that yet.

Pushing my senses past their limits is more painful than people think. You end up knowing everything—things you don't want to hear, don't want to feel, information you never wanted.

And what has to process all that data is a human brain, not a supercomputer. Enough information to make an ordinary person collapse bleeding from every orifice.

With a decent guide right beside me, there was no reason at all to endure that pain.

"Feeling better now, Clara?"

"Ah, um… Y-Yes…"

Finally free of the earlier shock, Clara slowly pushed herself up. She looked at me once, flushed pink all over again, then shook her head cutely side to side.

Don't tell me… she's trying to shake off the embarrassment? Does that even work? I swallowed the question and simply watched until Clara, restored to her usual self, came over.

"It's really dark in here, isn't it?"

"Yeah. Do you know how we're supposed to get in?"

"I don't know exactly, but… it's fine! I can see well even in the dark."

Soft fingers wrapped around my left hand. Before I could even ask, she pulled me along as she kept explaining.

"The underground of the Vatican Obelisk. Entrance Number One of the Celestial Observatory is a trap—a prison for people without clearance. Inside here, no electronic devices and no magic tools work at all."

"So that guy we just saw…?"

"Yes. He probably wandered in on his own and got locked in. Meeting you of all people was just his bad luck, sis."

In the absolute dark, Clara strode forward with confidence, chattering away.

"Still, I am a Saintess, so I did receive clearance for the Observatory. First time using it, though… It's amazing, seeing through the dark like this."

We walked another two minutes or so. With quick little steps, Clara went ahead and operated something. A thick steel door appeared out of the darkness.

A blast door marked A-1. A door that suddenly materialized from empty air without warning was rather fascinating.

"I'd like to explain this too, but things are urgent, so… I'll open it for now?"

With a heavy metallic rumble, a door that looked a full fifty centimeters thick swung open. I pushed Clara behind me and waited for it to fully open.

I didn't know exactly what was happening inside the Celestial Observatory. But making a rough prediction wasn't hard.

Cardinal Veneto, who'd gone silent. The unidentified World Government agent who'd been wandering the trap of Entrance One. And… as the door opened, the corridor of the Celestial Observatory beyond, filled with the light of red warning lamps.

"From here on, stick right behind me."

"Yes…!"

Winter Sword drawn, I stepped into the Observatory.

"Blow that damn corridor open already!"

"Impossible! We still haven't seized control of the internal turrets!"

"Fuck, what the hell are the hackers doing!?"

The underground of the Celestial Observatory. The pure white corridor, looking like something out of a sci-fi space battleship, was filled with shouting, gunfire, and explosions.

The Incineration Unit and the Observatory's defense systems. The Holy Knights guarding the interior. Both sides were equally desperate.

"Buy as much time as you can! We can't let those World Government bastards take the Observatory data!"

"What the fuck are these assholes even doing!? You can't break through that? If we don't get through in time we're all fucking dead!"

"Gyaaaah!?"

Thoom—!

A savage blast shook the corridor, and a B-rank Awakener who'd charged in boldly behind a shield evaporated.

"Fuck, before you lecture us, do something about those damn turrets! We have to close the distance before we can carve up those Holy Knight bastards!"

"We need time! We haven't even fully seized the Observatory's internal network yet!"

"You useless pieces ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠of shit? Do you know how much that gear you're carrying costs, and you can't even handle something this simple!?"

After several of the vanguard were chewed up by the Holy See's specialty penetrating rounds, the ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠engagement settled into a tedious stalemate of cover fire.

It couldn't be helped. The main forces of the Incineration Unit and the Execution Unit were still locked in battle with the Order of Holy Knights.

Having handed their main strength over to the main force, a detached unit that had come back purely to cut down the time had no power left to punch through the interior.

In the end, it was the Incineration Unit whose nerves were fraying. Once the data was uploaded and the World Government's invasion of the Vatican was exposed, this would no longer be a simple problem.

Just when they were considering throwing every remaining trooper into the breach—

"Hey, you idiots over there. Still haven't broken through?"

A variable appeared on the battlefield that had been holding its strange balance.

A cloak fitted with a shield generator and thick reactive armor. A tactical helmet with a solid black visor. The long sword at the waist, half-visible through the cloak. The elite of elites—the Execution Unit—had arrived on the field.

"Tsk. This is why I hate Holy Knight bastards. Nothing special about them, but they're ridiculously tough~"

A mocking ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠voice, completely out of place on a battlefield of flying bullets, shells, and magic, drifted out.

"Those turrets—we just need to take them out, right?"

"Ah, yes… that's correct!"

"Okay. Hey, everyone clear out!"

Whirrr—

The turrets that had been spitting fire sensed the change. The enemies lining the corridor all fell back at once, and about a dozen figures stepped forward with complete confidence.

The turrets' muzzles swung toward the would-be suicide cases who had so boldly presented themselves. Blue fire spat, and shield-penetrating rounds poured down like rain.

Tudududududu—!

Small grenades detonated, and dark smoke billowed up. In the blink of an eye the corridor was blanketed in black smoke, and the turrets—mistaking the silence of their targets—ceased fire.

That was when everything changed.

"That's all you've got?"

"!?"

Where the smoke cleared, a man stood tall with a blue shield still active. Judging they hadn't landed a solid hit, the turrets targeted them again.

"Number Three, clean up those toys."

"Yes sir~"

Machine tones and a modulated male voice crossed. The moment the turret miniguns spun up was nearly the same moment the man called Number Three took hold of his sword.

Pit—

A red thread of light cut across the corridor.

A half-beat later, a chain of explosions swept the passage. Turrets burst, lights shattered, and darkness so thick you couldn't see an inch ahead crashed down.

Explosions and footsteps. Machine warning tones and the emergency lights' backup generator spinning up. Amid the chaos, one Holy Knight opened his mouth.

"Holy Knights, all draw—gurk!?"

"Tsk tsk. This is why people who've lived peaceful lives on the inside don't cut it."

That was his cause of death.

To the Execution Unit, used to chaotic free-for-alls with no clear sightlines, a Holy Knight yelling at the top of his lungs and announcing his own position was nothing more than a convenient target.

"You… bastard…"

"You lot, sitting pretty at the Holy See, have no idea how fucked Siberia is. The first idiot who screams like a moron in front of monsters is always the first to die."

Crunch. The long sword twisted, and the Holy Knight's chest plate crumpled. The resisting man's body collapsed limply.

From the generator coming online to the emergency lights switching on took ten seconds.

More than enough time for the fifteen Holy Knights holding the corridor to be wiped out.

And more than enough time for a single girl to punch through the enemies occupying each corridor of the Observatory and descend to its deepest core.

"…"

Looking at the traces her ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠own created sword art had left on innocent Holy Knights, the silver-haired girl murmured quietly.

Vivid killing intent painted the girl's eyes red.