Chapter 6
‘Where am I?’
Nereia muttered, struggling to hold on to its consciousness as an immense impact hammered its entire body, threatening to knock it out.
Pitch-black darkness.
Pressure weighing down on its entire body. And a sticky liquid, too.
Nereia had resigned itself to death the moment the thing swallowed it, but let out a sigh of relief at having somehow survived.
In any case.
‘Am I inside its stomach…?’
That was the only conclusion Nereia could reach.
After all, its last memory was of being swept up by the suction and dragged into the thing's mouth.
It was then, as Nereia slowly looked around and considered its situation.
Sizzle-!
An ominous sound came from somewhere.
At the same time, Nereia flinched as it felt terrible pain and the sensation of its body melting.
Could this be…!
‘Stomach acid-!’
To think a creature barely 3 cm long could secrete stomach acid.
No, it caught prey with its mouth. Naturally, it would have a stomach to hold what it ate, and stomach acid to dissolve its food.
Unfortunately, Nereia had no time to calmly analyze the situation.
A system window appeared in the corner of its vision, issuing a warning.
【Warning! Your body is melting due to a powerful acidic substance!】
【If you don't escape right now, you might be in danger?】
Even without the system window's warning, Nereia knew better than anyone that it was in danger.
If only its Primitive Carapace were still intact, it might have been able to resist to some degree, but it had been shattered long ago after being grazed by the creature's tentacle.
At this rate, it would melt away completely and be absorbed as the creature's nutrients.
It had to escape before that happened.
But how?
Its Primitive Carapace, which could protect it from the creature's stomach acid, had long since been shattered. And even if it tried to tear through the creature's stomach and escape, its Primitive Erosion Tentacle, which could have done the job, had long since been torn to shreds.
No matter how hard it thought, it couldn't find a way.
On top of that, the fear that it might die kept it from thinking straight.
Was this it? Was it going to die just like this?
No. I don't want to die. I don't want to die yet!
I can't die pointlessly like this!
As the fear of approaching death grew, its reason began to run wild like a horse that had broken its reins.
Instead of thinking of a way to escape, Nereia could do nothing but struggle, thinking only that it didn't want to die.
Just then, something it had forgotten in its fear of death stirred.
【Primitive Mana Organ is activating.】
Primitive Mana Organ…?
Nereia managed to shake off some of its fear at the system window that had suddenly appeared in its vision, and wondered.
【The Primitive Mana Organ is supplying mana to the damaged Primitive Carapace.】
【The Primitive Carapace is regenerating through the mana supplied by the Primitive Mana Organ.】
Another system window appeared, explaining the situation.
Somewhere in its body, its Primitive Mana Organ moved the mana it had left and supplied it to the Primitive Carapace.
The Primitive Carapace greedily gulped down the mana supplied by the Primitive Mana Organ as it regenerated.
Though the mana efficiency was poor, this allowed it to withstand the Deep-Sea Predatory Larva's stomach acid, at least for a while.
With a little breathing room suddenly granted to it, Nereia desperately racked its brain.
‘If I can regenerate the Primitive Carapace with mana, couldn't I regenerate the Primitive Erosion Tentacle, too?’
There was a chance.
However, there was a problem.
To regenerate it, Nereia would have to divert some of the mana being supplied to the Primitive Carapace over to the Primitive Erosion Tentacle.
If it diverted some of its mana to the Primitive Erosion Tentacle while it was barely holding on, the Primitive Carapace would regenerate more slowly. Then it would melt away in the creature's stomach acid in no time.
In other words, all Nereia could do right now was keep regenerating its Primitive Carapace with what little mana remained and escape.
Having sorted out its thoughts, Nereia first charged at the creature's stomach.
But unfortunately, it was impossible for Nereia to break through the creature's stomach and escape.
It didn't know why the creature was built like this, but its stomach felt like solid muscle when Nereia rammed into it. No matter how hard it pushed its body against it, it didn't break or tear—instead, Nereia was pushed back.
Considering that the stomach walls of other organisms consisted of a mucosal layer, submucosa, muscular layer, and serosa…
The creature's stomach, which seemed to be made of muscle from the very start, was certainly strange.
That meant that, now that it couldn't use its Primitive Erosion Tentacle, directly tearing through the creature's stomach to escape was impossible.
But going deeper inside it was dangerous, too.
The stranger the creature's stomach was, the more likely it was that its digestive system was unusual as well.
If it went deeper, it would likely end up in an even more dangerous situation than it was in now.
And so, trapped in the creature's stomach acid and unable to do one thing or the other, Nereia once again thought through its options.
What should it do?
How could it escape this damn stomach?
What could it do…?
‘Ah…?’
As it considered the problem, Nereia let out a low murmur.
Come to think of it, why had it only been thinking about escaping?
Could this be the perfect opportunity to hunt the creature?
After all, the creature's outer shell was so hard that even its Primitive Erosion Tentacle couldn't pierce it while intact.
Which meant that even if it latched on and began feeding, it wouldn't be able to dissolve the creature's outer shell.
Right, just like the Deep-Sea Carapace Microbe it had first eaten at the hydrothermal vent.
But this place was different.
This was inside the creature's stomach. No matter how much the stomach itself was made of solid muscle, unlike the outer shell, it was nothing more than living tissue.
In other words—
‘I should be able to eat it, too.’
Even if it couldn't eat all of it, it should be able to eat some.
No, it had to eat it.
Its chances were fifty-fifty.
It couldn't be sure it would be able to eat it, but it was at least worth trying.
Better to do something than sit here, melt away in the creature's stomach acid, and become its nutrients.
So.
‘Please! Please! Please!’
Nereia poured all of its remaining mana into the Primitive Carapace and swam up through the stomach acid.
It reached the stomach wall in an instant.
Clinging to the creature's stomach wall, which was still spewing stomach acid and writhing madly, Nereia began feeding.
Its mana was depleted. The Primitive Carapace it had forcibly regenerated began melting in the creature's stomach acid once again.
There was no turning back now.
If it couldn't eat through the creature's stomach wall, it would die.
So.
‘Please-! Let this work-!’
Shouting those words inwardly, Nereia desperately began feeding.
How much time passed like that?
At the instant the Primitive Carapace melted away without a trace in the creature's stomach acid…
【You have devoured the biological tissue of a Deep-Sea Predatory Larva.】
‘Ah…!’
The system window told it that it had succeeded in eating the creature's stomach wall.
Nereia cheered inwardly in delight.
The more of the creature it ate, the more its depleted mana replenished, and its body and Primitive Carapace, melted by the stomach acid, regenerated. In addition, its damaged Primitive Erosion Tentacle and Primitive Propulsion Organ returned to their original forms.
With that, Nereia no longer had anything holding it back and began devouring the creature in earnest.
It broke through the stomach wall and devoured all the flesh beyond it.
Crawling forward with its fine cilia and greedily devouring the creature, Nereia soon realized that it was thrashing wildly.
It didn't know whether this was from pain or from the terror of being slowly eaten away from within.
‘I won.’
Nereia was certain of its victory.
The creature had made a mistake.
If it was going to swallow Nereia, it should have chewed it thoroughly until it was unrecognizable. Or it should have secreted stomach acid right away and melted it without a trace.
The arrogant belief that it was a predator and Nereia nothing more than prey…
‘…has brought about its own downfall.’
As Nereia continued eating its way through the creature's body, it sensed something.
This is…
‘Mana?’
It was mana. An immense amount of mana, sensed through 「Mana Sensitivity」.
But it wasn't only mana that it sensed.
Something else accompanied the mana. Clear. Pure. Like a flawless white untouched by even a speck of dust—what was this?
The moment it sensed that unknown something alongside the mana, Nereia moved toward it as if entranced.
Without eating any more of the Deep-Sea Predatory Larva it had been greedily devouring, Nereia moved solely toward it.
And then, Nereia finally came face to face with it.
The identity of the unknown thing it sensed alongside the vast mana.
It was a small fragment.
The moment Nereia saw something about the same size as itself, it instinctively thought of a gemstone.
But it wasn't any ordinary gemstone.
Something rarer. More beautiful. And of far greater value.
This was…
And this was none other than…
‘A biological core.’
Nereia instinctively realized that the thing before it was the biological core it had to eat in order to evolve.
At the same time, it devoured it.
The moment it came face to face with the biological core, it rushed at it without the slightest hesitation and swallowed it whole. Then it began to digest and devour it little by little, taking its time.
‘Ghk-!’
As it digested and consumed the biological core, Nereia groaned at the pain of an immense amount of mana and that unknown something surging into it like a dam bursting.
It hurt. It hurt so much.
It was a pain like its entire body was on fire. And like thousands of ants were crawling through its blood vessels, biting it wherever they could.
But—despite the terrible pain, Nereia did not stop devouring the biological core.
It knew, even without the system telling it.
If it stopped devouring the biological core now, it would become some ambiguous half-formed thing, neither one thing nor another.
It had to endure the pain and devour the Deep-Sea Predatory Larva's entire biological core to advance to the next stage.
And so, after forcing down the terrible pain and devouring every last fragment of the biological core, a system window appeared before Nereia's eyes.
【You have devoured the biological core of a Deep-Sea Predatory Larva.】
【Evolution requirements have been met.】
【Evolution Requirements】
＊Body size of at least 2 mm✓
＊At least 5 traits✓
＊Devour the biological core of a Lesser Predator or higher✓
The system informed it that by eating the Deep-Sea Predatory Larva's biological core, it had met all the evolution requirements.
At the same time.
【Unique Trait 「Mutative Evolution」 has been activated.】
【Analyzing the information in the devoured biological core.】
【Analyzing possessed traits.】
【Analyzing current environment.】
….
【Analysis complete.】
【■■■■ system user has deviated from the standard evolutionary lineage.】
【Calculating compatibility with the existing evolutionary lineage.】
【Compatibility: 0.7%】
【Warning. The current individual's evolutionary direction has deviated from the species' standard evolutionary range.】
【The evolutionary lineage is being reconstructed by the Unique Trait 「Mutative Evolution」.】
【Discarding the existing evolutionary lineage.】
【Generating a new mutative evolutionary lineage.】
【Searching for an evolvable organism.】
‘What? What the hell is this supposed to mean?’
Deviated from the standard evolutionary lineage?
Compatibility with the evolutionary lineage is a mere 0.7%? No, more importantly, there was such a thing as an evolutionary lineage?
Discarding the existing evolutionary lineage?
And creating a new one?
What the hell was this supposed to mean?
Looking at the system windows that appeared one after another, Nereia couldn't hide its confusion.
It couldn't understand at all what this damned system was babbling about.
But whether Nereia understood or not, whether it accepted it or not, the system seemed not to care. It simply continued saying what it had to say.
【Search complete.】
【Beginning the mutative evolution of ■■■■ system user.】
The system abruptly announced that its search was complete and unilaterally began evolution, leaving Nereia completely flustered.
But before Nereia could react, just as the system had said, evolution began.
It melted. Its body melted.
The body that had been transformed by the traits it had acquired by devouring various deep-sea creatures began to melt.
The fine cilia that let it move more smoothly through the deep sea.
The Primitive Mana Organ located somewhere in its body. The Primitive Carapace that had provided sturdy defense.
The Primitive Propulsion Organ and Primitive Erosion Tentacle, created by fusing two or more traits.
And everything else that made up its body began to melt and blend together.
But that wasn't the end.
【Absorbable biological tissue detected nearby.】
【Absorbing biological tissue.】
‘What is this now…!’
Nereia, struggling to hold on to its consciousness as it felt itself being flung far, far away, shouted in surprise at yet another system window appearing in its vision.
Absorbable biological tissue?
The only thing nearby was…
‘The Deep-Sea Predatory Larva, right? Don't tell me it's going to absorb that?’
Nereia's guess was right.
The Deep-Sea Predatory Larva's corpse began to be sucked into Nereia, whose body had already melted and blended together.
This insane system was even using the corpse of the already-dead Deep-Sea Predatory Larva as fuel for evolution.
In the end, Nereia couldn't endure the process and lost consciousness.
But even though Nereia had lost consciousness, the system did not stop the evolution.
Eventually, the Deep-Sea Predatory Larva's corpse, being absorbed through Nereia's evolution, shriveled and contracted like a dried-up mummy.
Before long, the shriveled corpse of the Deep-Sea Predatory Larva split open, and something slowly emerged from within.
At the same time.
【Evolution complete.】
【Growth stage increased.】
【Congratulations. You have evolved into a new species.】
【A new evolutionary lineage has been applied to ■■■■ system user.】
【Species: ???】
The system announced that evolution had ended successfully.