Astor 

Amid the universe, there exist countless worlds that all share the same timeline, but do not interfere with or affect one another—the multiverse. A great thinker from a certain world was the first to propose the idea. Each of these countless worlds continued to walk its own distinct history, closed off from any others. However, this immutable law eventually began to crumble.

World Erosion. A phenomenon that visited worlds where this law was broken. As the term implies, the worlds were eroded away as if by wind and water, headed toward their own destruction. No matter how unreasonable, those who lived in these worlds at the brink of destruction had no choice but to accept it.

However, one sole organization tried to fight back. Its name was Logos, the Dimension Inspection Agency—an organization with the power to intervene in many worlds that enforced justice behind the scenes. Following the principles of absolute justice and absolute spacetime, they cast a watchful eye over many worlds in order to stem World Erosion.

Astor was a young enforcer who had achieved top marks at Logos. Given the power to intervene in other worlds, she wielded her sword to stop the rampant World Erosion phenomenon.

Astor's duty was to travel between Otherworlds—the term for the other worlds seen from Logos's home world—and deal with the World Erosion detected in each one. Erosion phenomena manifested in different forms from world to world.

They varied widely, from paranormal and unexplained phenomena to objects and life forms that shouldn't exist in those worlds. Some were observed by headquarters, others by on-site investigators.

Phenomena had been observed by headquarters in the world the newly appointed Astor was headed to.

"—Verified. Eliminate erosion phenomena."

Astor looked between the creature in front of her and the marker displayed on the device in her hand. Once she confirmed that it was an erosion life-form, she put the device in her jacket. It was a humanoid insect that had wandered through a hole to the Otherworld and underwent abnormal evolution from the drastic change in environment. It had evolved so far from whatever type of insect it used to be that it even had its own language.

"—rrr—Θ*'—!"

In response to its orders, all kinds of native insects came flying in toward Astor. Aster drew her sword from the sheath hanging from her ivory-white jacket—and the next moment, the abnormal specimen lay in two halves on the ground. She swung the sword from above her head down toward the ground, sending the yellow-green liquid stuck to the blade flying.

"Hardly felt a thing from this one either."

Astor let out a sigh and began disposing of the remains of the abnormal specimen she just dealt with. Since she was appointed the proud role of enforcer, she carried out all the duties that came her way in an instant.

"Maybe the investigators thought it would be strong..."

The specimen she defeated had a hard outer shell that deflected bullets, but she was able to slay it easily. As excited as she was to meet a strong opponent, barring extreme circumstances, Astor would probably never meet the type of being she was looking for. She shook her head as she thought about it.

"It's pointless. Makes it sound like I'm hoping for the world to collapse, huh?"

It was a wish born out of pride. Enforcers must discipline themselves. Mumbling that she had to be stricter, Astor resumed her work.

After finishing the disposal and confirming that she had prevented erosion in the area, Astor sent a report to HQ through her device. Just then, she noticed HQ had sent her a message. Apparently, she had new orders.

Her new orders were to handle a case of an investigator going missing in a world where no erosion had been detected. Such a thing was not unheard of, but it was quite rare. Naturally, Astor had no experience with it.

"...Hm?"

At the end of her instructions was the name of the enforcer she would be working with.

"Clayg? What's a senior enforcer doing in this Otherworld...?"

What reason could they possibly have to dispatch him to that world? Or rather, did they think a new recruit who only eliminated abnormal specimens couldn't handle a survey mission? Whatever the case, she would only find answers on the scene.

"There aren't many chances to work with a senior enforcer. I've got to learn from him."

Astor, who lived by a code of quick and decisive action, entered the specified coordinates into her device and stepped through the Otherworld portal that deployed in front of her.

Astor teleported to the backstreets of a city. Logos enforcers could generally walk around the city so long as they didn't act conspicuously. Still, having to teleport out of sight was something of a hassle.

For now, she would look around to assess the situation. Everywhere she looked, Astor saw buildings like heaps of scrap iron that looked ready to collapse at any moment. She looked up at the sky only to see a hazy fog in the air, making it hard to tell the time of day. A red light blinking at regular intervals looked down from the wall towering behind her.

"...It's uncomfortable."

The first thing Astor felt was displeasure with this city called Neon Nebula. For Astor, with her excellent hearing and love of quiet places where she could calm her mind, the information overload of Neon Nebula was just plain uncomfortable.

"The places I go aren't always places I'll like. I have to get rid of my personal feelings to be a good enforcer."

"Precisely, Astor."

Astor heard a sudden echoing voice and automatically reached for her sheath, standing ready. She took steady breaths and looked ahead intently, where she saw a person leaning back against the wall, wearing a gray coat and a hat that bent toward the sky. A bluish-white light peeked through their metallic armorlike head, flickering gently.

"Sorry, I must have startled you."

"Are you...Mr. Clayg?"

"That's right. Apologies for my appearance."

After a bit of conversation, Astor gathered that Clayg wasn't a very strict person, in contrast to his appearance. She got a strange impression from his flat, unemotional manner of speaking, and his attitude that was the exact opposible of her instructor at HQ.

"We'll be partners on the same mission," he said. "Our mission is only to investigate and quickly resolve the problem. If you have any good suggestions, I'd like to hear them."

"Understood."

After setting up a shared channel for the mission on their devices, they got to discussing the particulars.

"Mr. Clayg, wouldn't it have been better to set our coordinates to the survey location to begin with?"

Astor had realized that the location they had lost contact with the missing investigator was far away from them, and questioned Clayg about it at once. He seemed to understand that, too.

"This 'Neon Nebula' is a bit special. I thought it might be troublesome to suddenly teleport into darkness."

"Darkness?"

"It would be best to see it for yourself," Clayg said, then jumped up high. He placed a hand on the starcase that zigzagged up to the top of the outer wall, and began to climb.

"W-Wait a moment, Mr. Clayg!"

When Astor caught up with him, she saw a world of darkness extending as far as the eye could see, in sharp contrast to the dazzling city. No light shone, apart from the area lit by light filtering out of Neon Nebula. There were no light sources in the sky, such as a moon or stars.

"I guess this might have been confusing," she said.

"Well then, let's proceed with the investigation at once."

"Understood."

The two headed into the dark land to pursue the missing Logos investigator.

The moment she left Neon Nebula, Astor felt a paralyzing chill. Her bodysuit automatically regulated her body temperature, but her face completely stiffened up. Just then, a silver liquid floated out from Clayg's coat sleeves. It swirled around and transformed into smooth spheres. One floated alongside Astor, and the other by Clayg.

"What's this...?"

Astor stared curiously at the silver sphere. Looking closer, its surface was a thin, stretched-out film, glowing and illuminating its surroundings by some indiscernable principle. The spheres' light was so powerful, one might even think it was midday. Strangely, the light wasn't blinding.

"I'd heard you could manipulate a silver fluid, but—wow, you can do anything with it."

"That's right. It's very versatile."

He stopped speaking and continued forward. Before long, the pair arrived at a dam-like structure. The signal displayed on the device was close by. They followed the illuminated walkway atop the wall that held back the upstream water, where they discovered three men lying on the ground. One of them was a Logos investigator. The people next to him were most likely staff who managed the dam. They had no external injuries, nor were there any signs of a fight. Just as Astor tried to get closer, an alert sounded from the device in her pocket.

"An erosion signal!?"

"They seem to be eroded bodies."

"Eroded bodies" referred to those whose bodies were taken over by Lemures—life-forms that appeared across the multiverse, regarded by Logos as the utmost threat. They had the horrifying ability to get inside a person's body and take over their consciousness. The discovery and elimination of Lemures was an important task given to Logos members.

"Seems like a fairly weak reading," Astor said.

The danger level shown on her device was much lower than typical values detected from eroded bodies. Astor had never heard of another case like this.

"Just who did this?"

"It at least looks as though we won't find any further clues from them," Clayg said, lifting up the three bodies with ease. His gaze was fixed on the end of the path, where there was some kind of administrative building for the dam. "Let's investigate there."

The pair went to look at the administrative building near the dam where they found the eroded bodies. It was a two-story building with a guardhouse on the first floor and a control room on the second. There was no sign of anyone inside, nor were there any erosion signals. There were no traces of a fight, either. Most of the operation appeared to be automated. The only personnel were the three eroded men. As Clayg flipped through a journal left in the guardhouse, he heard Astor's voice from the other room.

"This way, Mr. Clayg."

He headed over to see her with her hand on an ordinary-looking wall.

"I felt air flowing. There must be a path to somewhere beyond this," she explained.

Astor had noticed the slight breeze with her sharp hearing. Then, for some reason, she reached for the sheath hanging from her coat. She drew her sword with imperceptible speed and smashed the wall apart in an instant. At the same moment she sheathed the sword, the door lost its support and toppled backwards.

"All right, let's be quick," she said.

Clayg immediately reached out with his silver liquid and supported the broken halves of the door so they wouldn't fall over.

"Mr. Clayg, what are you doing?"

"You're a bit lacking in composure sometimes, hm?"

"What?"

Clayg's eyes shone with a faint light, as if analyzing her. "I guess that drive is what led you to becoming an enforcer."

"What are you trying to say?"

Astor raised her voice somewhat, but Clayg continued matter-of-factly, "You're worked up right now."

He had accurately pointed out her condition. Astor was speechless as he calmly pressed further.

"Your duty and your personal feelings might one day land you in a dilemma. Furthermore, recklessly making a show of incredible strength may give rise to unforeseen dangers."

"Then you think using that liquid of yours isn't worth it?"

"That's right."

Clayg moved the sphere following him to the palm of his hand, and it began changing shape.

"You still don't know what this can and can't do."

It was just as he said. Enforcers each had a special power. Astor's was exceedingly straightforward—superhuman physical abilities specialized for combat. On the other hand, she had a sneaking suspicion that Clayg hadn't even shown a glimpse of his power. Those he fought would be forced to devote their attention to his unknown abilities. Astor just had thought of him as an enforcer who could control a silver liquid, but much like a flower floating at the water's edge, she only saw what was at the surface. She couldn't have imagined just how deep that flower's roots grew.

"..."

Between his unreadable expression and his unknowable nature, Astor's breath caught in her throat. "I'll...be more careful from now on."

"That said, I think your power is harder to hide."

"I-I already knew that much!"

A correction—he did seem to have a mischievous side to him.

"Well then, why don't we find out what you've discovered here?"

Clayg continued into the room behind the hidden door. The room contained a spiral staircase leading deep underground. Clayg once again formed the silver liquid and tossed the sphere to the center of the stairwell. Then, perhaps because he couldn't be sure the stairs were safe, he jumped straight down.

"Are we supposed to be cautious or not!?" Astor groaned, before jumping down the stairs after him.

Through the passage that continued beyond the spiral staircase, they arrived at a facility. Countless pipes ran along the walls and ceiling of the spacious interior, each connected to a tank or machine. The room was filled with a unique smell and the sound of water running underfoot.

Astor furrowed her brows and uttered, "This must be...where Neon Nebula's wastewater goes."

"Hmm, let's have a look."

Clayg activated his device and instantly scanned the room for threats, but there were no readings of note. It was unclear if all of the wastewater treatment occured here, as the facility's considerable scale meant it was divided into sections for each step of the process.

They found a staircase leading down and headed farther underground. As they went down and continued checking the area, they found a strange signal coming from one level. The room's shape displayed on the device was different from the other floors, and one part was colored black on the device. The pair nodded to each other and headed for the uninvestigated area.

What they found was a huge cylindrical machine. Both ends had clear windows through which they could see inside. Astor brought the silver sphere closer to see inside the liquid in the tube.

"!?"

Inside, a living creature with a translucent body floated—

—Beep! Beep!

A sudden alarm rang out, and something rushed into the room. It was a sphere that emitted a pale purple light. It rolled to one side, then made strange sounds and began changing shape—before long, it transformed into something with the upper body of a human and many legs, like a centipede.

"This must be the defense system," Clayg said. "We've found the dark underbelly of this city."

The living weapons of the defense system appeared before Astor and Clayg one after another. Their arms were equipped with rapidly spinning circular blades, making an unpleasant sound as if they could slice a person to ribbons in an instant.

"Mr. Clayg. How would you handle this scenario?"

"Logos is an organization that excises erosion. We mustn't get involved in anything else. If our technology leaked to Otherworld inhabitants, they could evolve in unforeseeable ways."

He spoke calmly as the living weapons continued to surround them. Their insectlike legs were designed so that they could move freely around pipes and machinery. Whoever had created them was an excellent engineer. The swarm of living weapons regarded the pair as enemies and began moving all at once. Just then, Astor stepped forward.

"I'll handle them."

"Would you like my help?"

"None needed."

Astor exhaled sharply—and vanished without a sound.

Shing.

A metallic scraping sound came from nowhere. It was the sound of Astor, now far away from Clayg, sheathing her sword. Without changing her expression, she declared, "It's already over."

A gust of wind had swept through the room, and the many living weapons were all sliced in half.

"Fine work, Enforcer Astor."

As the thin sound of his applause echoed around them, Astor remembered what he had said about her earlier.

"Senior Enforcer Clayg."

"What is it?"

"It seems it's better for me not to hold back my power."

"Is that so?"

"My apologies for disregarding your advice."

When Astor said that to him, Clayg showed no signs of concern and simply replied, "I don't mind. I think the organization is stronger for bringing together those with different mindsets."

"Uh, right."

He truly was an inscrutable person. Though he talked about the organization's pros and cons, his words were emotionless, so whether or not he was serious, Astor couldn't tell.

Astor and Clayg quickly left the treatment facility, wary of additional reinforcements. Normally, they would have eliminated the life-form in the cylindrical machine here. However, it was possible the facility was deeply connected to the city's functionality, so they could not execute it immediately.

When they returned to Neon Nebula, Astor turned to Clayg as they overlooked the colorful neon cityscape from a rooftop and asked, "Shouldn't we let HQ know about this situation?"

Clayg shook his head. If HQ intervened, then at worst, this Otherworld would cease to exist entirely.

"This Otherworld is still on a lower layer. Whether we call them or not, our efforts here won't change that."

"But I don't think we can take out the mastermind without impacting the social system on a broad scale."

"We can."

Astor held a small object up to the neon lights between her fingers. There were three marks engraved on it.

"This must be the name of the factory that created those living weapons."

"IDC. One of the corporations that rules Neon Nebula," Clayg said.

Ibis, the head of that corporation, seemed to be the mastermind behind the scenes of this massive city.

"I see. So then we assassinate the head, and that solves it."

"Don't be too hasty. We won't have our solution until we find out who's behind the erosion phenomenon."

Clayg turned his gaze once again to Neon Nebula's cityscape. Beyond the shining blue light he stared at was a tall building that stood out from all the rest.