Fabre in Sacheon’s Tang Novel - Chapter 497

Chapter 497
The simultaneous presence of pufferfish and shellfish toxins made me cock my head in puzzlement.
This was a natural reaction. To the best of my understanding, no poisonous animal employed both venoms concurrently.
‘If it’s from a pufferfish, the agent must be tetrodotoxin. And if it’s from shellfish, and the Tang Clan elders have verified it… then it’s likely saxitoxin, not Vibrio.’
Tetrodotoxin is unquestionably the poison found in pufferfish—nearly every toxic variety contains it.
Concerning shellfish, the options are narrowed to either Vibrio bacteria or saxitoxin. However, if the Tang elders classified it as a lethal poison, then Vibrio was probably not the cause.
This period in time does not make a clear separation between poisons and bacteria, but unlike Vibrio, which cooking neutralizes, saxitoxin remains potent even when heated. Therefore, if they declared it a deadly poison, it was almost certainly saxitoxin.
‘If the Tang elders labeled it lethal, the situation must have been grave.’
So why was I so adamant that no creature uses both?
Although tetrodotoxin is most famous for being in pufferfish, numerous other organisms also utilize it—blue-ringed octopuses, certain marine snails, some crabs, vipers, newts, toads, frogs, starfish, and specific flatworms.
Some manufacture it themselves, while others gather it from symbiotic bacteria residing on their skin.
Saxitoxin, however, even though detected in some shellfish, is not generated by the shellfish or their symbiotic bacteria.
It comes from marine dinoflagellates. Shellfish and crustaceans collect it after consuming these toxic algae, and humans are poisoned by eating the tainted seafood.
So, if an individual eats cooked shellfish and dies?
Then it is almost surely due to saxitoxin.
This indicates there are no documented instances of any creature actively using both toxins.
One is a defensive poison employed by marine and amphibious animals.
The other is environmentally accumulated—stored within the body, not created by it.
No known creature aggressively uses both poisons.
Yet, if we consider the parallels between them, there is reason to believe they were mixed by design.
“The victims succumbed to heart failure, is that correct?”
“It is.”
“Because both toxins cause the heart to stop?”
“Yes, Hwa-eun.”
My adoptive father verified this, and Hwa-eun appeared to acknowledge the toxins’ impact.
Indeed, both tetrodotoxin and saxitoxin immobilize the heart—they are neurotoxins.
As neurotoxins, they induce paralysis, which eventually stops the heart and results in death.
Comparing their strength: the median lethal dose for saxitoxin is 0.57 mg.
For tetrodotoxin? Approximately 2 mg.
That is a difference in potency of over four times.
Nonetheless, their method of operation is alike.
The human body operates on minute electrical currents.
To transmit signals for muscle movement, sensory input, and heart rhythm control, the body depends on sodium ions.
Both tetrodotoxin and saxitoxin attach to sodium channels and prevent sodium from entering.
This ceases neural communication, paralyzes muscles, halts respiration, and finally leads to fatal cardiac arrest.
And here is the intriguing part—when combined, the outcome is instant and fatal.
‘Essentially, a neurotoxic mixture.’
This led me to conclude it was probably not a new poisonous beast or spirit creature.
The flawless cooperation between these two poisons indicated it was the deed of an individual with profound knowledge of toxicology.
I inquired of my adoptive father,
“You couldn’t locate the perpetrator, but you presumed it was a new Five Venoms Sect creature because of the pufferfish and shellfish toxins?”
“Yes. That was the elders’ conclusion. There was no evidence of any animal, but the poisons matched those from venomous creatures. So they suspected a new breed.”
As I anticipated.
This era is unaware that saxitoxin originates from dinoflagellates and builds up in shellfish.
They probably assume the shellfish generate it themselves.
From that, it’s simple to suppose a new venomous beast or spirit creature was to blame—particularly when no animal traces were discovered.
I shook my head.
“It could have been a human.”
“A human? But there were no witnesses—not a single clue.”
My adoptive father had ruled out a human culprit due to the lack of evidence.
So I clarified my reasoning for believing a person was more likely.
“Yes. If it were a Five Venoms Sect beast or spirit creature, it would likely be one of their artificially altered venomous kinds. And those are always derived from existing poisonous animals, correct?”
“Yes, that is true.”
“Correct. And based on my knowledge, no creature uses both pufferfish and shellfish toxins together.”
“What if it is a creature you are unaware of?”
He raised the possibility that one might exist beyond my knowledge.
But I considered that highly improbable.
“The chance is virtually nonexistent. And I have another reason to suspect a human. Both tetrodotoxin and saxitoxin share a characteristic—they numb the extremities, stiffen the body, and ultimately stop the heart.
But when used in combination, they produce a powerful synergistic effect.”
“Synergy?”
“Yes.”
“Is that truly accurate, So-ryong?”
Even Hwa-eun seemed astonished—this was apparently information even she lacked.
In the realm of venomous creatures, toxins are usually employed singly for strength. And the Tang Clan prefers its own specialized concoctions.
But when mixed, these two poisons cause rapid death.
To where?
To the next world.
Both poisons disrupt sodium ion movement—but through different mechanisms.
Tetrodotoxin obstructs the exterior of the sodium channel.
Saxitoxin blocks the interior.
So when both are present, the signaling network collapses entirely—no nerve signals can pass.
This phenomenon has been examined in contemporary studies.
‘Why would someone combine the two? I suppose this world has many inquisitive minds like mine.’
Reflecting on it, I surmised another curious individual had done the same.
“Yes. Pufferfish toxin and shellfish toxin both cause bodily paralysis. Saxitoxin operates from the inside, while tetrodotoxin works from the outside. Together, they result in immediate paralysis and death.”
“I was unaware of that. I believed they were merely alike.”
Hwa-eun looked impressed as she comprehended, and then my adoptive father spoke again.
“So you are suggesting… it is highly probable a human was responsible?”
“Yes. My estimation is that it was someone at the Flower Realm tier.”
“F-Flower Realm!?”
My adoptive father started at the words.
This was only natural—it signified an expert master had appeared on the enemy’s side.
To my knowledge, a Flower Realm master is equivalent to the Three Sovereigns and Five Emperors of the martial world.
And our side had no such figures present here.
“Then this is grave. We must notify the Murim Alliance and urgently call for at least one of the Five Emperors…”
He meant we needed to summon someone powerful enough to pursue this foe.
But I smiled and comforted him.
“There is no need for excessive concern. We already have two Flower Realm masters here.”
“Two!?”
My adoptive father was astounded.
Well, technically it is three.
But I chose to keep that to myself.
***
As foreseen, the wedding was delayed.
With people dying and the front lines falling back, if I were to marry now, it would only destroy morale.
Life is unjust, certainly—but when one person perishes in combat with nothing but soil in his hands while another, born to privilege, celebrates a marriage? Of course morale would plummet.
So we determined to conduct the wedding after this issue was settled.
How?
Noblesse oblige.
A moral duty that accompanies status.
I would assume the responsibility to intervene.
Only after I ended this crisis in a dramatic manner—and when people acclaimed my name—would I hold the wedding.
Because I am a man for the people, am I not?
“Right, if there are two Flower Realm experts here, even if the adversary is at that level, it should not be difficult to defeat them. I will inform the Murim Alliance that you have both attained the Flower Realm and will be taking action. That ought to lift morale.”
“Understood, Father.”
Before proceeding to the bamboo outposts constructed for night watches, Hwa-eun and I went to inspect the bodies.
I had not planned to go—but Hwa-eun demanded to see everything personally.
Merely to be certain, she said, we should validate the precise poisons used.
‘The elders already managed it. I am sure they were thorough. Hwa-eun’s attentiveness is nearly extreme.’
Still, I had no option but to accompany her. Even though the thought of confronting corpses disquieted me.
We reached the site, guided by Tang Clan elders who appeared less than pleased, their faces stern.
“These are the bodies.”
“Thank you for your efforts.”
“It was nothing. I heard the tidings—you reached the Flower Realm?”
“Yes.”
“Congratulations. We always had faith you would achieve greatness one day.”
“Thank you.”
These elders were watching over the bodies, and from the grins on their faces, it seemed the news had gotten to them via the warriors of the Venom Blood Squad.
Hwa-eun, however, stayed cool and detached.
‘They were so dismissive of her for being female before…’
‘Release it, Hwa-eun. It is all history now.’
She was likely still harboring some bitterness, so I attempted to soothe her wordlessly.
But irrespective of her sentiments, Hwa-eun was ever meticulous. She tested the corpse with a needle and affirmed the poison type.
“It is unmistakably pufferfish toxin and shellfish toxin.”
“The proportion?”
“There is a far smaller amount of the shellfish toxin.”
“How much less?”
“There is roughly four times more pufferfish toxin than shellfish.”
“Then it is nearly confirmed this was a human’s work. Pufferfish toxin is about four times less powerful than shellfish toxin.”
Since saxitoxin is four times more potent than tetrodotoxin, employing them in this ratio signified the poison had been precisely calibrated to a 1:1 lethal dosage.
That is the proportion that kills most effectively.
And no creature can measure dosage like that—unless it is human.
‘This only supports my hypothesis.’
I was growing increasingly convinced it was a person.
Just then, while inspecting the body, Hwa-eun seemed to notice something.
“Hm? What is this?”
She indicated the corpse’s mouth, now pallid in death.
Why was she even inspecting the mouth?
Scowling, I bent closer—and glimpsed something white within.
“Appears to be leftover noodles.”
“Does it?”
A mass of sodden noodles, partly decayed, was lodged inside the mouth. I flicked it away absently and covered the body once more.
I did not wish to continue gazing at the corpse’s face any longer.
For some reason, the mouth was fixed agape and the eyes had remained open, implying the body was discovered long after death. It was profoundly disturbing to observe.
“Everything is confirmed, then. Exactly as we were told. Let us capture the villain tonight and exact vengeance for them.”
“Yes, So-ryong.”
‘We will avenge you. May you find serenity in the afterlife.’
I pledged it quietly.
***
Night descended swiftly.
We advanced quickly toward the border area, now accompanied by Gun Hye-rin.
Naturally, we also brought Sister Jeokwol, Cho, Yeondu, Hyang, Hongdan, Moji, Soji, and even Heukhwa and Baekhwa.
When we arrived at the region we had reconnoitered earlier that day, we observed the bamboo towers ascending along the border.
In my previous life, these would be watchtowers. I concentrated my inner vision—and could discern warriors moving anxiously inside the outposts.
The Murim warriors who had earlier withdrawn had now reclaimed them, likely to lure the enemy out.
No one had been slain during daylight, so they had seized the chance to regain the guard posts.
Hovering in the air, I gestured downward and signaled.
[We are almost at the area we surveyed earlier. As arranged, let us proceed to our separate hiding places.]
[Understood.]
[Received, So-ryong.]
We would each hide in a designated spot nearby.
The zone we selected for tonight’s ambush was among the bamboo towers along the border—specifically, the section directly before us, where prior deaths had happened.
To the left flowed a broad river; to the right rose a mountain.
No deaths had taken place at the outpost on the cliff across the river. But between that river and the mountain, in twelve outposts—people had died.
So we resolved to conceal ourselves in this sector.
Upon reaching the Flower Realm, the first significant change is enhanced Qi perception.
If another Flower Realm master materialized, we would undoubtedly detect it.
We divided the twelve affected towers into three sets of four—each set monitored by a team from our group.
I alighted near the mountain, setting down Gun Hye-rin and Yeondu in the grass.
[Remember, if the enemy appears, your task is to contain them—prevent their escape. Then summon the others.]
[Understood. But I borrowed a sword. I do not anticipate requiring assistance.]
She had borrowed a sword—presumably because she anticipated battling a Flower Realm master.
She delivered a correct response… but her tone implied something clearly:
She completely planned to manage this on her own.