Inside the Cave of Obscenity

"Kuaah..."

Kara woke up to the bright light coming through the window and stretched out on the couch she was using as a bed.

Her body was limp.

Her head was heavy.

It was not that she was sick, it was just that she hadn't been sleeping well.

It had been seven days since she got the slime's core.

The refugees from Fonteau and Jenna, as well as the bishops who promised to support them, had told her to find an effective countermeasure as soon as possible, and it was the result of working her head almost day and night without a break.

But, well, that was not so different from what she had been doing so far―― it was the usual thing, she thought vaguely, and Kara, the owner of the room, sluggishly raised her body.

Before she knew it, a white coat instead of a blanket fell on the floor.

"Hmm?"

It was a white robe that she didn't remember using. It was clearly bigger than her size.

Rather than wondering whose it was, she first got up from the couch and stretched her body.

Blouse on top, shorts and black stockings underneath, the usual outfit for ease of movement, was illuminated by the dazzling sunlight coming through the window.

The dazzling sunlight shone through the window and she could see her white blouse through her legs that was lacking of flesh.

The woman was in her twenties, but her breasts were small and she was short.

That was one of Kara's problems.

She had a talent for swords and became a warrior priestess but the reason she was now in a position to oversee the researchers in the tower was that she enjoyed experimenting.

The fact that she was able to draw out unknown effects from what was already there―― something that no one had thought of before―― was what made her twist her brain every day instead of swinging her sword.

And so she came up with new potions, tools, and weapons that may or may not be useful.

It was interesting enough when someone would use something that she had thought of.

The people around her think that she had a research-oriented way of thinking, but she also had her own problems.

(Because Jenna-sama said strange things...)

Kara stood in front of the only mirror in the room, shaking her sleepy head and bedraggled hair.

Her long hair hid her eyes, and it was unkempt. Even if she tried to comb it, it would get entangled and would not go through.

When she put on her favorite black-rimmed glasses, there was a woman standing there with a dull appearance.

But the other day.

It had been almost a week now, but Jenna, who had helped her for a little while, saw Kara like that and understood that she would be cute if she was well-groomed.

(Me?)

It was the first time she had ever received such an evaluation.

No, when she was still using the sword, she had kept her hair short because it got in the way and was easy to maintain, and she think she had taken care of her appearance that time.

She tried to remember herself back then, but it was many years ago.

"I wonder if I should cut my hair... but it's too much trouble."

It wasn't that it would interfere with her research.

Kara muttered as she plucked up a tuft of her bangs in front of the mirror, but then thought better of it.

As she said, it was just too much trouble.

It was the kind of thing that lead to Kara's reputation as a "beauty when done right" to this day, but she guessed that was up to the individual.

A dozen minutes later, Kara was thinking and looking at her usual self, assessing her appearance in front of the mirror with a simple touch up. She was calm.

"Well, it's research time again. Research."

She eventually settled down there and muttered that in a slightly lively voice.

There were times when she think she wanted to get married someday, but it was only "someday".

She thought that it didn't have to be now and didn't mind being single for a while.

Being alone had benefits.

She could wake up whenever she wanted, work whenever she wanted, and sleep whenever she wanted.

She didn't have to eat food she didn't like, and she didn't have to do things she didn't like.

That kind of relaxing way. Or should she say, not her body but her mind was relaxed?

Thinking about that, she combed her unkempt hair with her hand and picked up a document on the desk in her room.

It was a document containing a progress report on an experiment that was currently being conducted in the research tower that she managed.

"Hmm... after all, having a real, living monster made the experiments go much faster."

It was simply convenient to be able to conduct experiments that would normally take weeks or months to complete due to lack of materials, but with the infinitely multiplying monster cells at hand, it was possible to shorten the time.

It was visually unpleasant to have the slime as a material for the experiment, but there was a big difference between having the material and not having it.

She was researching tools and weapons that were effective against the bodies of monsters born from the Demon King's mana.

If it worked on the slime, she could try it on the cells of other monsters, or ask adventurers and warrior priests to try it on living monsters.

The most important thing was that it was a living monster, which pleased Kara more than anything else.

Even if she made a potion to disintegrate the cells of a dead monster, she didn't know if it would work on a living monster.

The fact that it was alive and active meant that it was resistant, just like humans were.

A dead piece of flesh could be destroyed, but a living cell may resist and endure.

There were warrior priests who had died in that way―― but what they were using now in the research tower was a living slime cell.

It was a rare existence that was imbued with mana and resisted magic and poison.

Kara thought that a tool or potion that could destroy that kind of monster would have a certain effect on any other kind of monster.

Originally, the demon king's mana―― monsters were born only from the demon king's mana, which no longer existed because it was defeated by the heroes.

"All right, let's work hard today."

Every day was fun for Kara.

She was able to obtain new research material, which continued to multiply infinitely as long as she fed it.

She could do a lot of experiments with it.

How could she make the mucus body disintegrate?

How could they neutralize the magic it used?

How to find its nucleus efficiently? How to lure them. How to put them to sleep.

There were so many things she wanted to do.

Even though it was the one that destroyed a country, for Kara, it was only one of the research materials.

……Suddenly, she noticed a bottle mixed in with the documents.

It was a bottle that contained a light purple liquid.

At first, she couldn't remember what it was, but.......

"Ah."

Before... the priests who actually ruled the holy city Lishlua. One of them asked her―― it was a prototype of the "potion" she was asked to do.

A drug that would arouse those who would take it. In other words, it was an aphrodisiac that would force the user to go into heat.

Kara let out a sigh, remembering that when she had asked him why he needed such a thing, he had gone on and on about how it was necessary to have excellent offspring.

"That reminds me, I need to finish this one too."

She said that in a tired tone, a change from when she was thinking about the slime.

The reason was simple.

It was not fun.

First of all, there was no such thing as an "aphrodisiac".

It was a drug that was supposed to elevate one's mood and make them think that they were in heat unconsciously.

If anything, Kara thought it was more like a painkiller.

So, this "aphrodisiac" that she made was just a mixture of several kinds of herbs that sharpened the sensations, numbing the mind, slowed down the thinking ability, and by adding the divine power from the goddess Fasalina, it would enhance its effectiveness. It was just that.

It was not available anywhere, but anyone could make it if they want to. That was about all there was to it.

"Hmm……"

She scratched her unkempt hair wildly.

The scale in her mind was definitely tipped in the direction of the slime research, and to be honest, she didn't have the slightest interest in creating an aphrodisiac.

Theoretically, it was complete.

The only thing left to do was to test it on a human body―― of course, she had already tested it on a guinea pig, a laboratory animal, to make sure it was not life-threatening.

However, the guinea pigs got excited just by smelling it, and when they ingested the liquid, they were in heat for a whole day.

Kara had made it as a drinking potion, but apparently, the goddess' divine power had a stronger effect than she had imagined, even by smelling it...... injecting it was also effective.

What was the difference between drinking it and pouring it on the skin? Was it safe to use on a human body, and what were the effects of using it?

It was the only way to find out, but who would really want to try a suspicious potion like a prototype aphrodisiac?

"In the end, that's the problem, right?"

The reason why the aphrodisiac was not completed was because of that. There was no one to test it on.

And there was no way that such a suspicious potion could be given to someone who was in charge of the country.

"Kara-sama, are you awake?"

As she was remembering the process of developing the aphrodisiac, there was a knock at the door.

The voice sounded familiar, it was one of the researchers.

"Yes, I'm fine. What's wrong?"

"The slime cells are gone, may I give it some "food"?"

"Hmm―― I'll go with you."

Feeding the slime―― different from that of livestock, and Kara responded in a tense voice.

When she left the room, she saw a man with tired eyes standing there.

He had dark circles under his eyes, and his expression was lackluster. However, his eyes were bright and shining, as though he was looking forward to the upcoming experiment...... His eyes were like those of a child.

He was about the same height as the average adult male.

And Kara was only about the height of a male researcher's chest.

(It's not that he was a big guy...... it's just that I'm too small.)

"What's wrong, Kara-sama?"

"No...... Anything unusual, then?"

"No, not really. The slime's nucleus is isolated in an iron box, and several warrior priests were present when feeding it, and were wary of unforeseen circumstances."

"Good. Even with just a nucleus, it is still a monster that has destroyed an entire country."

"......Even with such a small nucleus, it's terrifying when you put it like that."

Despite saying that, the man's eyes still shined happily.

However, Kara chuckled to herself that she would have the same look in her eyes.

The two of them walked quickly―― at the same pace as usual―― to the laboratory on the third floor of the research tower.

Normally, the main function of that room was to test the potions they had prepared on the second floor on guinea pigs, but now the guinea pigs were transformed into slime cells, and in the center of the room, the slime's nucleus was kept in a metal box.

There were always three warrior priests standing around the box.

"Good morning, everyone."

Kara greeted, and the researchers and warrior priests in the room greeted her back.

As she listened to them, Kara walked over to the iron box.

The size of the box was such that even the petite Kara could easily hold it up in both hands. The only thing inside was the nucleus of the slime―― a round sphere about the size of the tip of her index finger, so even a light poke would cause a dry, rolling sound to come from inside the box.

"With a steel box, you can't see what's inside, so it's troublesome."

"If it's glass, there's a risk of it being broken from the inside."

One of the warrior priests responded to Kara's muttering in a disciplined manner. It was a woman.

Unusual, she thought. It was a rare occasion that Kara's attention was drawn to something other than her research subject.

"I haven't seen you around."

"My name is Alp, and I was assigned here yesterday. I would like to thank you for your cooperation, Kara-sama."

A priestess with striking peach-colored hair greeted her and bowed.

Her ponytail fell from her shoulders as gravity pulled it down, and her big breasts, which far exceed those of the saint, Jenna, swayed so lavishly with just that gesture that they almost make a plopping sound.

It was a magnificent bulge that even Kara, who was of the same sex, could not help but follow with her eyes.

When she raised her face, she saw that the white and blue vestments of the warrior priests were distorted at her chest.

She looked down at her own breasts, but then remembered that there were people around her and cleared her throat.

"I haven't heard anything about replenishing the warrior priests, but......"

It had been about ten days since the refugees from Fonteau gathered at the sacred mountain, and the slime that destroyed the country began to appear around the holy kingdom of Lishlua.

Kara had heard that the warrior priests had gathered around the Goddess' barrier and were being sent out to take down the slime―― or so they called it―― on guard.

The peach-haired priestess, who introduced herself as Alp, had a slightly clouded expression on her face as she thought about the fact that there should not be enough manpower to put a new guard of warriors in the research tower.

"That... it's hard to say, but I'm terrified to stand on the front lines."

"What for――."

――Why did you become a warrior priest, Kara was about to ask, but then she remembered something.

"Oh, Alp. You, are you the priestess who encountered the slime?"

Hesitant to say the word "attacked" as a woman, Kara spoke to Alp, choosing her words unusually carefully.

Alp understood what Kara was trying to say and nodded, her expression was slightly clouded.

"It's unusual. The bishops respected the will of an individual."

But that was the end of the conversation.

Kara took her gaze off of Alp and once again turned to the iron box that contained the slime's core.

(The first woman to be attacked by the slime in this country, huh?)

When she opened the iron box, she found a black sphere inside. It was lying at the bottom.

When she shook the box, the sphere hit the wall of the box and made a dry sound. The sound was light. It was evident that the sphere itself was light.

However, it would take in anything they feed at it and turn it into its own body.

(Isn't it accurate to say "body"?)

It was not flesh, it was liquid.

At first, Kara and the rest of the research team wondered how to increase the number of slime cells, but that problem was easily solved.

"Well then, let's take guinea pig number 27 for today."

"Yes."

The guinea pig was a small mouse that had died because it could not withstand the experiments.

If they gave it a carcass, the sphere would extend its few remaining tentacles and devour the carcass, absorbing it.

What was given to number 27....... it was a poisonous potion that was effective against goblins and lizardmen.

It was not a powerful poison but it could be fatal by ingesting it.

Goblins and lizardmen were carnivores, and if they couldn't get food, they would kill each other and eat even their own race.

The potion turned the flesh of those who ingest it into poison.

When the goblin's flesh was poisoned, then when it returned to its nest and was eaten by its companions, it would kill them―― a poison named "Nest Killer".

"By hearing the effects and experimenting so far, this "mutant"......, which we call it because it is difficult to call it just a slime, it absorbs the characteristics of the beings it has taken in, but―― Will it take in the properties of the "nest killer" and destroy its own kind?"

"I placed the hourglass."

In order to time the predation accurately, Kara and the researchers used an hourglass.

There were no tools to measure time as accurately as in Fonteau, where the knowledge from the hero flourished, and time was calculated with an hourglass, which was recognized in this world.

At the same time, a male researcher behind wrote down Kara's words on parchment, word for word.

Kara threw the carcass of the guinea pig affected by the Nest Killer into the iron box.

The three warrior priests became tense.

In particular, Alp, who had been attacked once, had already removed her mace from her waist and was clutching it with both hands. The other two also had their hands on the hilts of their swords.

"I'll turn over the hourglass."

"Hmm... no change. Do you not like the poison of "nest killer"?"

(Until yesterday, it was immediately reaching for the poisoned meat she gave......)

When Kara thought so, a tentacle extended from the slime's nucleus, as though in fear.

It was small tentacles.

A dozen or so tentacles, like that of a sea anemone, extended into the guinea pig carcass.

The tentacles entwine around the corpse when they realize it was meat, and countless more thin tentacles extend from there, swarming and swallowing the rat carcass, which was many times the size of a sphere.

"Ugh..."

The three warrior priests groaned in unison.

When it came to Alp, she turned her face away and held her mouth.

"Are you not good at tentacles? If you feel uncomfortable, you can stay downstairs."

"N-no. I'm fine."

She didn't seem to be all right, but her sense of duty as a warrior priest kept Alp from going out.

If she was out on the front lines and made a blunder there, she could be disqualified from being a warrior priest.

Because the reason for her dislike―― being attacked by the slime and watching it prey on her companion would be painful for a normal human being―― Alp was still young. She was too young. Kara thought that she might be feeling pessimistic.

Well, that didn't mean that she would stop her research.

"Alp... -san? Can I call you Alp?"

"Ah, yes. Of course, Kara-sama."

"Alp, do you know the difference between this mutant and normal slime?"

While the slime took in the guinea pig and digested it, Kara, who was bored, spoke to the newcomer Alp.

"The difference, is it?"

"Yeah, the difference."

Alp didn't understand when she was suddenly told that.

In all honesty, she shook her head and replied, "No."

"First of all, they take in the abilities of what it took in―― this "abilities" is special...... I suspect that it also absorbed the "experiences" humans have such as the understanding of magic and swordsmanship."

"Experience?"

"I heard on the refugees from Fonteau that this slime used magic of various attributes and easily defeated a knight with excellent fighting skills. Humans can only use one to three spells, depending on their affinity. I remember hearing that even the Queen of Fonteau, who is a half elf, can use four or five."

"But" Kara paused.

"This slime is more than that. Moreover, it is said that its total amount of mana is different from that of human beings, and even the queen of Fonteau, a mage who was said to be comparable to the demon king, was defeated―― even though it is supposed to be a slime that cannot use magic. Based on that, we can expect that it has absorbed as much magic knowledge and even mana from the number of beings it has taken in."

She predicted.

"But there is no sign of this slime's nucleus using magic. Based on that, I expect that the amount of liquid in the slime is proportional to its mana―― in other words, the bigger it is, the more powerful it is, the more mana it can use."

As Kara finished speaking, there was a change in the slime inside the box.

To be precise, to the tentacles swallowing the guinea pig.

The guinea pig carcass in the mucus, its body hair melted and its skin exposed. Then its skin melted and blood began to ooze out.

"Then there's this growth rate. The mucus, which earlier was only thick enough to restrain the guinea pig, now wrapped around its entire body."

When Alp heard the explanation, she looked inside the box with a sense of dread.

The sight of the guinea pig melting―― while it was a nauseating sight, but certainly...... its mucus was increasing.

Fast enough that one could see.

"There is a limit to the amount of mucus a slime's nucleus can control. Until now, it was usually the size that fits in the palm of one's hand. And at best, it can attack livestock. It never grew much larger than that. But this mutated species is different. According to the refugees, some of the slimes are as big as a two-story house."

After comparing the information and studying the biology of the slime, Kara's words sent a shiver down Alp's spine.

An unpleasant sweat flowed down her face.

She was aware that her cheeks were twitching.

"Now, how to get rid of such slime――? It's not just about defeating the slime. This might be the one that we have to destroy."

She then put on a pair of gloves made of thick leather.

She then proceeded to collect the newly multiplied liquid using a metal spoon, which the slime's mucus could not dissolve.

"According to the information, this mucus should have absorbed the "Nest Killer's" poison―― Alp, do you think it's possible for slimes to kill each other?"

Alp couldn't answer.

A mutant slime that multiplied, grew and absorbed without limit. It was all she could think about.

"I don't think it's possible with this poison. Slimes absorb each other. And they share information. A good example of this is when countless slimes use multiple spells. I believe that whatever poison is mixed in there, they will deal with it."

"Then, isn't this research meaningless?"

"No. Research is a process of eliminating possibilities one by one and arriving at a few correct answers. It's not pointless―― we'll gain some information even if this poison doesn't work."

Kara laughed with some sense of accomplishment.

The eyes peeking out from between her unkempt hair were serious though, not smiling at all.

"So I'm going to flip that. To be precise, I will mix the slime's cells with the power from its natural enemy and turn it into something it can't absorb."

"Unabsorbable?"

"It's the power of the goddess Fasalina. There is no greater poison for monsters than that, but there is a limit to the miracles of the goddess that an individual can use. It's our job to make up for that."

Monsters were born from the power of the Demon King, and the Demon King and the Goddess were opposites.

The power of the goddess was poisonous to the demon king's monsters, and the power of the demon king was also poisonous to the human race, the goddess' children.

An existence that repelled each other.

That was why Kara's experiment could be the only natural enemy of the slime.

Thinking that it was the way to break through, Kara dripped a few drops of beautifully clear liquid into the slime's cells she had just collected.

"That is……?"

"I dissolve the herbs that can only be found at the top of the sacred mountain, and squeeze out a small amount of juice from them―― This herb contains the divine power of the goddess, and only a few drops of the liquid from the herb can modify the effects of a mere poison to a deadly poison against monsters."

"???"

Alp, who was not familiar with research, tilted her head, but she sensed something in the liquid that was even more powerful than the miraculous power of the goddess used by the priests.

"I think this will prevent the mutants from taking in their own cells....... At least, the poisons we developed until yesterday have been reported to have some effect on the slimes surrounding the Goddess's barrier. Now, all we have to do is try out some new poisons."

Inside the metal box, the little guinea pig was already dissolved to nothing but bones, with pieces of flesh floating in the tentacles of the slime.

It would only be a matter of time before it was completely melted.

"How many times did you turn over the hourglass?"

"It's four times."

"It was slow to stretch its tentacles earlier, but the melting time is the same as before"

Kara said and filled a test tube with the liquid she had collected.

She gave it to one of the warrior priests who was watching them.

"Give this to the front lines. When they use it, tell them to keep an eye on the mutant for a full day to see if there are any changes."

"Understood."

"Well, then. Next―― let's use guinea pig number 36."

Not paying attention to the warrior who hurriedly left the lab, Kara gave the next guinea pig to the slime.

The next thing she knew, another warrior entered to replace the one who left. Then, Alp and the two warriors tensed up, wary of the slime while Kara experimented on it.

It was repeated.

The guinea pigs that died from poison were absorbed and the slime's cells were harvested to produce a poison against the mutant slime, the Black Ooze.

Until they created a "poison" that was truly effective to the slime.

For the slime, the act was not painful.

It was only natural since it didn't have any sense of pain in the first place.

Trapped in a metal box, fed, deprived of its cells, and then trapped in a metal box again.

The cycle repeated.

There was one thing that Kara and her team, who were experimenting with the slime, were not aware of...... If they hadn't missed it, the research would have been completed.

If she was intelligent enough, she could have created a poison that would kill the Black Ooze.

Because it had already ingested a poison that was effective against the Black Ooze.

It just took a while for the effects to manifest themselves, and the information from the front lines had not reached them.

That was why.

With a few more days, Kara and the others would have known about the "poison".

From there, they could have mass-produced it.

If only...... they had known that these slimes had wisdom.

"Next, guinea pig number 19."

"Yes."

The slime was listening to the voice.

A female researcher named Kara.

The woman who created the "poison" that stimulated the instinct of the Black Ooze. The woman who made "something" that the monster's instinct could not go against.

Her name, her appearance, her information. The slime was sharing it.

A young warrior named Kuryuel and a middle-aged warrior named Oteria, who had been taken in the other day. It was the information it had gotten from the two of them.

The slime was looking up at the woman through the small nucleus.

It was looking up at her.

It was looking up.

It was looking――.

It was――.