The Gate. That was what he called it.

In a man-made, unnatural room, green and red lights were flickering. Two men were fixing their gazes to numerous lined up gauges.

One was in his early forties. He wore a white gown. At a glance, his appearance would look like that of a scientist. However, any effort to keep a cool composure still couldn't hide his nervousness. Frequently combing his hair and pushing up his glasses didn't help, either.

One was a little younger. He was in his late twenties. He didn't give a single speck of what he was thinking or anything resembling emotions. His eyes were locked on the gauge's reading.

"On the Azure Grimoire, the Prime Field Device Type Zero, Murakumo Unit..."

The man with glasses, who was watching the gauges, lifted his face. His eyes were sharply narrowing at the sight that had spread before him.

There, a particular glass panel had been installed to one of the walls. On the other side of the glass, something was clearly visible.

What could be seen was something that looked like the crater of a volcano. Thick red liquid was burning furiously. It was squirming within the hole of the solid rock surface.

It could also be seen as the pulse of an unreasonable creature.

"This definitely falls to an unconventional category... But having come this far, it feels like any common sense would be meaningless, yes?"

The voice was directed to the expressionless young man by his side. But the young man didn't even glance to where the voice was coming from. The side of his face looked like it had been hardened with wax. Within it, only his cold, apathetic lips moved slightly.

"... The Kusanagi is..."

"What's wrong, Relius? To completely purify Kusanagi, a little bit more time is necessary, but..."

The gentleman with glasses had begun speaking, but he was interrupted. The wax-faced man called Relius, who had been sitting the entire time, suddenly rose up from his chair. Then he hurriedly went out of the room.

The man with glasses who had been left behind also hurriedly chased after him.

They went inside an elevator from the corridor and finally descended to some place. They were in front of the object that looked like a giant crater, which could be seen across the special glass panel from before.

The two men who had been running around were standing around the vicinity of the crater.

"Relius! You were the one who said not to do any unnecessary intervention to the "Gate", weren't you!?"

Rushing up, the man flinched from the overwhelming heat. The man with glasses raised his voice to compensate for it.

Whether because of the might of the whirling flames, or perhaps because he had no intention to turn his face from the beginning, the other man stared down the gigantic cauldron-like object.

"What's the meaning of this...? There is no response from Kusanagi. There is something from deeper within...."

"Hey! What's going on, Relius Clover!?"

"This is... I see. The opposite side of the Boundary—"

Suddenly, black mist gushed out from the crater.

Its violent force swallowed Relius' words, then instantly engulfed him entirely.

"Wha...!?"

Something was happening.

The black mist spread endlessly in front of the wide-eyed and shocked man with glasses. The force was drastically growing greater and the heat increased the pressure of the atmosphere.

Relius was nowhere to be seen. Any trace of him being swallowed had also vanished.

"Uh... Ah, ah..."

Something was happening.

It was beyond the man's comprehension.

A phenomenon no one had witnessed before was swirling about. It was stretching and squirming, as if taking some sort of a form.

Slowly, something had appeared, raising its crooked neck upward... it was somewhat similar to a snake.

Before long, the enormous body had reached its critical limit and began trembling. It burst and flew out in an instant.

"UWAAAAAAAAAAAHHHHHHH—!"

Even the man's scream was swallowed. The mist demon, roaring and causing tremors, was spurting out, and then it surged as vigorously as ever.

Trampling all kinds of logic, it kept growing higher and higher.

Thus, there were almost no remains left.

Only the eroded wall ruins of the measurement room and an unnaturally silent cauldron were left behind.

The silver full moon hung on the sky.

It was a place that was connected to everywhere, yet could be reached from nowhere.

It was a place where everything looked like illusions drifting about.

Thick ivy covered the entire sides of the old castle's walls. Within one of its room, there was an aging white haired man sitting alone. His body sunk deep within his profound seat.

With his youthful but wise eyes, which matched his piling age, he stared at the water's surface, similar to a mirror from a stretched silver tray.

All that was occurring in the world was projected there.

...As well as dismays and sorrows.

"Clavis-sama."

A voice was raised behind the aged man. It was the voice of a man with deep composure.

Without turning his head, the aged man glanced to where the voice came from. He answered while lightly molding his hand to support his cheeks.

"Valkenhayn, isn't it? ...I assume you bring bad news."

"In accordance with the international summit meeting held not too long ago, the resolution to launch a nuclear strike on Japan has been confirmed. Judging by the current circumstances, I fear it will be carried soon enough."

"I see..."

The aged man's eyes were clouded with grief before dropping down their sight at the reflective water surface.

"It can no longer be avoided, then. If that was their decision, then there is nothing we can do... I am but only a mere observer."

What sort of outcome would their decision make? A better future? Or complete destruction?

The constant questions within the aged man's mind grew silent, as well as the projections of all of the world's incidents on the reflective water.

Without warning, black mist gushed out from within the earth. It took the form of a gigantic serpent with numerous heads. Mankind called that mist demon, which appeared so suddenly, the "Black Beast".

The Black Beast's only instinct was to destroy.

Anything and everything, it destroyed entirely.

The elusive beast could not be matched by anyone's powers, nor could it be hurt by any kind of strength. In the end, humanity decided to destroy the land where the Black Beast appeared.

It was surely the very last measure that could be taken.

However... the being didn't die.

The Black Beast leaped from the scorched earth and spread all over the world.