Gopogopo――.
From upstream a muddy water flowed.
A few years ago, the water in the river was so clear that anyone could see the bottom, but it was contaminated due to the infrastructure that was standing right now...... It was built by a hero who appeared from another world.
The water was now so muddy that it was impossible to even see its bottom, and the garbage and wastes from every household living in the royal capital were mixed in.
The infrastructure was the basic physical structures and public facilities needed for the operation of a society.
It was to improve the quality of life.
For example, road maintenance and expansion.
The royal capital and its surrounding villages and towns. Or its neighboring countries.
By improving the roads that lead to the capital, it would help travelers to easily come and go, the number of people visiting the capital would increase, and as the number of people increased, the businesses would flourish, and as the business flourished, the industry would develop.
By improving the water supply to every household, people's lives would become easier, for example, bathing, which was only used by the special class of people such as the nobility, would spread to ordinary households. By practicing proper hygiene, it would maintain good health and prevent diseases.
With the construction of the sewer system underneath the royal capital, garbage and wastes would flow into the sewers and reduce the amount of garbage from accumulating the streets above ground.
If the amount of garbage was reduced, the number of harmful pests such as mice that feed on it would be reduced, and the spread of the disease would be prevented.
In this way, life in this world had continued to grow over the past few years, which normally would take decades or even centuries.
However, some sacrifices would be made by making people's lives easier.
One of them was this river.
In response to the fact that nature would be polluted if garbage were to be flushed down the river, a reservoir was built at the end of the river, where the water was purified using magic.
However, the river would still become polluted in this way, and even though magicians purify the water using magic, it was still not perfect.
In the first place, before the wastes reach the tank, the dirty water would deteriorate the soil surrounding the river, and dirt accumulated in places where people would not notice.
It would be fine right now.
But in the future. Decades from now. In a few hundred years.
Someday, if not prevented, the surrounding nature would end.
It would.
By sacrificing one place. It would enrich people's lives.
And once people experienced that way of life, they would be reluctant on going back to the old ways.
Instead, they would aim to improve life more, which would bring them life without great effort.
That was what humans were. That was what people were.
But――.
"Hmmー?"
That day.
There was a water tank placed far away from the royal capital.
The place where garbage accumulated had a bad smell, and no one could approach it without a good reason.
It was a place where no one would go unless they had a good reason to due to the place littered with wastes and emitting a foul smell.
The man in charge of managing the water tank made a puzzling voice as he carried a wooden stick on his shoulder to remove the garbage from the river's edge.
He was a young man, probably not more than thirty years old of age.
He was wearing a green-colored tunic and brown-colored pants.
The skin peeking out from the green-colored clothes was tanned and healthy.
The man brushed his golden hair lightly with his right hand and scratched his temple.
His gaze was on the dirty and murky water, wondering why the trash flowing in the river was getting lesser and lesser recently.
Yes. Garbage had lessened.
In the past, he would have to walk back and forth from the water tank to the drainage ditches several times a day to make sure that the garbage would not accumulate and did not block the flow of the river.
That was why the man made a puzzling voice while lowering his gaze and peering carefully into the river.
The water in the river was still dirty as usual, but there was less garbage.
Rather than less... there was almost no garbage.
That would make his job easier, as the man hoped, but the problem might be in the sewers.
If the garbage wasn't flowing into the river, it would mean that something was blocking the garbage inside the sewers.
So, not being able to just ignore it and be happy about it, the man looked at the river for a while, then turned his gaze upstream and let out a sigh.
"What should I do?"
Normally, if the garbage was blocked, he would have to go into the sewers to remove the thing that was blocking the wastes.
Otherwise, the accumulated garbage would block the water, and in the worst case, the water from the sewers may flow back to each household in the royal capital.
To prevent that from happening, he was getting a high salary to manage it, but... the man didn't feel like doing it.
It was the sewers, after all.
The water that was flowing through it was dirty and smelly enough to make anyone feel nauseous if they were not used to it.
Going into the sewers meant that he would have to be surrounded by that stench.
The thought of going to such a place made him try to avoid it as much as possible.
The man shrugged it off for that reason and stopped.
"Well, maybe tomorrow"
It hadn't been long since the garbage had stopped flowing.
The sewer would not suddenly flow back tomorrow or today.
More importantly, the fact that the sewers had been there for several years and had never had a backflow of water dulled the man's sense of crisis.
Something smelled.
It was a strange smell.
It was so strong that it almost turned his nose, but once he got used to it, he didn't mind so much.
Yes. Got used to it. If one got used to it.
People were creatures that could grow accustomed to things, both good and bad.
At first, they were confused and anxious about the change and hesitated to build a facility that they didn't understand, even though it was from the hero's words.
However, now they were not worried about the facility that would improve the quality of their life, and they were spending their daily life with much more convenience than they did a few years ago.
It would never change.
No. Rather, this world would improve more conveniently in ways they could not even imagine.
It would change.
The man thought so, and as well as the people who were living in the royal capital... everyone involved with the hero would think so.
The world would change.
The monsters were eliminated by that change and would disappear from the world.
Yes, that was what they thought.
It was a fact. From the time the Demon King was defeated, until today, the damage caused by monsters had decreased and the number of monsters had visibly decreased.
That was why.
People would forget.
They would only look at the good things that were convenient and would forget about the inconvenient things.
Their fear was fading being replaced by the fun and enjoyable moments of their lives.
Torotoro.
The dirty water bubbling was visible but he didn't pay much attention to it.
All he could think of was that he had to do some troublesome sewage cleaning.
Peace dulled their sense of crisis.
Making it impossible to imagine that kind of situation.
Peace was natural.
There were no more enemies.
One day, the world would be like that.
However, the world was not yet like that.
"Maybe I'll talk to the adventurers later."
The man walked along the river toward the water tank, repeatedly saying that it was troublesome.
If the man had been serious about his work, would the outcome have been different?
......It would not change.
The world could not be changed by just a single person.
The outcome could not be changed.
It was the hero who saved their world, but the hero was no longer in this world.
A change in the sewage system.
If he had discussed it with the authorities today instead of tomorrow.
Perhaps the worst outcome could have been avoided.
But it was too late now.
The man would talk to the adventurers about the sewage problem tomorrow. As for today, he decided to take it easy and go about his business as usual.
The dirty river... The impurity was becoming visibly thicker.
The man was oblivious to it.
The river in which all the wastes from the royal capital flow was always dirty, and even though the water was a little darker, it was the same as usual.
So, he didn't notice it.
It was becoming darker and more tainted―― it became solid with a slight sticky that was different from the usually dirty water flowing in the river.
It gets caught on a rock at the bottom of the river, changed its shape, and flowed down the river.
Not just one.
More than one soft-like body flowed down the river.
The water tank was ahead.
The wastes collection point.
For those soft body things, there was food ahead.
The man, oblivious to the change, walked along the river...... and suddenly stopped in his tracks.
"Oh"
He found a piece of trash, probably from the sewers, caught on a rock by the river.
He crouched down and reached out his hand to grab it.
The water was dirty, but that was always the case.
The man reached for the trash without worrying about it.
There was nothing to be alarmed about, just business as usual.
But――.
"What!?"
Suddenly, the dirty water rose and wrapped around the man's wrist.
The man's body stiffened in surprise, and the sensation in his outstretched hand from the wrist down disappeared after a moment.
It continued from his arms, shoulders, chest, half his body, and neck.
"――, ――――! ……"
He could not utter a sound.
He could not maintain his posture.
The man lost his balance and fell straight into the dirty river. With a loud sound of water, it splashed water and stained the ground.
It was a strange sight. The man who fell into the river was unable to get up on his own and was flowing in the river...... without going wild.
The man's body, deprived of its freedom by the paralyzing poison, could not swim, and he just floated in the river, face down.
He could not breathe.
Finally, he inhaled a lungful of the dirty river water and died.
The man's body flowed down the river...... and sank in the middle.
It was impossible to see clearly in the muddy river.
The wind blew, and the trees with fresh green leaves on their branches swayed beside the river.
Someday, the trees would die, sucking in the water from the river polluted by the flow of garbage.
It was a beautiful sight. It was so quiet and gentle that it was hard to believe that a corpse had just disappeared.
The corpse did not float away from the river.
It was eaten by the river.
Isn't that the most accurate way to describe that?
With the man gone, only a beautiful scene remained in the place.
No one was watching.
Only the quiet scenery remained.
No one was there.
Just the water flow from the polluted river and the sound from the trees and grass swaying in the wind.
That was it.
Then, a gurgling sound. An unpleasant sound echoed.
A long time had passed since the man had been swept away by the river.
The sun was setting, and the sky was turning twilight instead of blue.
There was an unpleasant sound as something crawled out of the river.
As soon as it crawled out from the river, it began to move with a slow, sluggish movement.
It was a creepy thing.
It was like a giant slug. Even though it was a slug, its body was so huge that it could swallow a man and still have room to spare.
It was probably a size larger than a domestic cow.
If someone were to look closely, its body was quite transparent.
Its body was the same color as the dirty water from the river. And inside its transparent body, there was a figure of a man.
It was the man who was in charge of managing the water tank and had just been taken by the river earlier.
He was not alive.
He was slowly being digested inside...... the slime, which looked like that of a giant slug, was not moving.
Then the slime started to move slowly.
Taking in and digesting the grass in its path.
After the slime had moved, only the ground could be seen. It seemed that it could not digest the stones, so there was only soil and stones left.
As the slime slowly made its way toward the royal capital, another giant slime crawled out of the river.
Many. More than one. There were many of them.
There were more than ten of them, each coming from different directions, but all of them were moving toward the royal capital.
Some of the slimes were trying to take in and digest wastes, rats, and food scraps in their transparent bodies.
These slimes were born from Tiana and the other women in the sewers and then absorbed the wastes from the water tank at the end of the river and the garbage that was collected by the man earlier.
Their mass was so huge that it was hard to believe that they were just newborn slimes, and above all, their appearance was horrifying.
These slimes were moving forward.
Through the world of twilight.
They had traveled about half the distance from the place they had crawled out and onto the royal capital.
Finally, the sun was completely hidden behind the mountains, and the darkness of night was upon the world.
The slimes, which were originally black and murky, blended into the darkness of the night, making it difficult to see them.
It would be difficult to see the dirty black slimes from the watchtower of the still distant outer wall of the royal castle.
They would not expect something like this.
It seemed as though the world was on the side of the slime.
The world was becoming more and more convenient thanks to the wisdom given by the hero.
However, it was also true that nature was being sacrificed in return.
Perhaps it was the reason why the world sided with monsters instead of humans.
More than a dozen slimes were moving forward.
The destination was the royal capital.
The slimes, darker and more fearsome than the darkness, moved through the world that was becoming enveloped by the darkness of the night.
