Also known as turtle shell rot disease, this condition is surprisingly common among fish and other aquatic animals.

Commonly referred to as water mold infection, it describes fungal growths that form on injuries or parasite-damaged areas, caused by fungal spores. While the specific causative agents can vary, when this condition affects turtles, it’s known as Shell Rot.

A compound word—Shell, meaning shell, and Rot, meaning decay.

It’s a very intuitive name.

In fish, the disease manifests as visible mold or infection on the body, but in turtles, it causes literal rot of the shell.

Symptoms vary. In some cases, the entire surface of the carapace or plastron becomes thinly infected and turns whitish with rot. In more severe cases—like with Elder Geumdo—localized areas rot deeply into the shell.

Elder Geumdo had said his back began to sting before he could no longer move, so the rot was clearly deep.

It had probably started on the shell and penetrated inward, even affecting internal organs.

As I checked the extent of the damage, Hwa-eun approached while holding her nose and asked,

“So-ryong, do you know what it is?”

“Yes. This is shell rot disease—turtle shell rot.”

“This stench... it’s really from decay, isn’t it?”

“That’s right, Hwa-eun.”

“Can it be cured?”

I nodded.

If left alone, Elder Geumdo would’ve died eventually. But now that Spicy Fabre was here, it was like meeting Hua Tuo himself—the greatest doctor in the Central Plains.

I’d actually treated this condition many times in my past life.

‘Elder, you’re going to live easily for another hundred or two hundred years.’

“Of course. We’ll dig out the rotten area, clean the wound with medicine, and let you sunbathe.”

“Dig it out?”

Hwa-eun’s eyes widened.

Probably because this was a time without modern surgical procedures. I explained:

“Yes. The shell has no pain receptors, so it’s best to remove the rotted areas. If left alone, the rot will spread to other parts of the body.

If untreated, it could be fatal, so it’s definitely better to remove it.

And the shell will grow back, so there’s nothing to worry about.”

Shell rot, if left untreated, can be fatal—but treating it isn’t difficult.

This case looked deep, but if we removed the infected tissue, disinfected it properly, and provided food and sunlight, recovery was guaranteed.

Since this was a spiritual beast, food wasn’t necessary—disinfection and sun were all we’d need.

“Oh, and I’ll need your help too, Hwa-eun.”

“My help?”

“Yes.”

But we had to be cautious in choosing the right disinfectant.

Typically, antifungal agents or povidone-iodine are used to treat shell rot.

Especially for disinfection, povidone-iodine is essential.

It’s widely used and trusted, and although someone might think alcohol could be a substitute—never use alcohol inside the body.

Turtles cannot metabolize alcohol. Using it internally could actually kill them.

So, without povidone-iodine available, we needed a different herbal disinfectant—and I was counting on Hwa-eun’s expertise in poisons and medicinal plants.

She’d know something useful.

“Do you know of any herbs used to treat pus or inflammation? I’m sure the infection has reached internal tissues, and we’ll need to wash it out with medicine.”

Strike while the iron’s hot—I brought it up now. After thinking for a moment, Hwa-eun answered:

“For pus and inflammation? We could use dandelion and fish mint.”

“I’ve heard of fish mint. What about dandelion?”

“It’s a weed that grows in the fields and mountains. It blooms white or yellow flowers, and when it seeds, you blow on it and the fluff scatters in the wind.”

“Ah, that’s dandelion!”

So Hwa-eun meant dandelion and fish mint.

Perfect. We’d either boil them and use the decoction to cleanse the wound, or extract their juice and use it topically.

“Then let’s remove the rotted section and rinse the internal tissue with the decoction made from dandelion and fish mint.”

“Thank goodness. I’m so glad it can be treated. This creature carries the legacy of my ancestor—or rather, maybe I should say Elder?”

Hwa-eun beamed with relief as I explained the treatment plan.

But even though treating the shell rot was simple, what came after was the bigger problem.

“But treating it is the easy part. What comes after is the issue.”

“What do you mean?”

“I’ll explain while we talk to Elder Geumdo. Cho, Yeondu.”

As Hwa-eun tilted her head, confused, I called for Cho and Yeondu to take us back to Elder Geumdo’s head.

Once we arrived and Cho called him, Elder Geumdo’s urgent voice immediately bubbled up.

—Brgrrr.

『—Tssrr! (So? Can it be cured?)』

Cho, acting like a proper elder interpreter, even mimicked an older tone.

It was adorable—I almost laughed. But I quickly sobered up and spoke with all the seriousness of a doctor addressing a patient.

“Yes. It can definitely be cured.”

—Brgrt!

『—Tssrrrt! (Really!? That’s a relief!)』

Elder Geumdo was visibly overjoyed.

Of course he was—he probably thought he was going to die, only to be told there was hope.

But now came the real issue.

‘The hard part comes after.’

“However, even if we cure you, I’m still worried.”

—Brgrt?

『—Tssrt? (Worried? About what?)』

This translation is the intellectual property of Novelight.

“Because the real risk of this disease comes after treatment. If the environment doesn’t improve, it could come back.”

—Brgtt!

『—Tssrrr! (Come back again!?)』

In the darkness, Elder Geumdo’s golden eyes opened wide.

He was clearly shocked.

In turtles, the main causes of shell rot are stress, lack of sunlight, and deteriorating water quality—all of which lower their immune system and allow mold to fester in wounds.

Given the current conditions, Elder Geumdo likely developed it due to lack of sunlight and filthy water.

A back buried in sand and the muddy waters of the Yellow River.

A terrible habitat for a turtle.

People assume turtles are so docile and hardy they can thrive in any condition, but water quality is absolutely critical.

So even if we treated the disease, if the environment stayed the same, it could easily return.

“Yes.”

—Brgrrrrr.

『—Tssrrrt. Then what should I do!?』

At Elder Geumdo’s question, I looked down at the murky river beneath us.

“First, you’ll need to move. The Yellow River isn’t good for turtles. And all that sand on your back—it needs to be cleared off.”

—Brgrt? Brgrrrrr.

『—Tssrrrt. (What? Move? And remove all this sand too?)』

Cho echoed the elder’s surprise in his voice.

It was clear Elder Geumdo was startled.

And then, the explanation came—why Elder Geumdo had stayed here and carried so much sand on his back.

—Brgrr. Brgrt.

『—Tssrt. Tssrrtssrr. (As I grew larger, people kept spotting me. They tried to capture me, rip off my shell, so I could only come out of the water at night.)』

So Elder Geumdo had wandered around, avoiding places where people gathered, and eventually found this muddy riverbank and decided to live here.

The muddy water kept people from noticing him. He’d piled sand on his back to avoid catching human eyes as well.

If the Tang Clan had released him, he would’ve been in the Yangtze River... So why had Elder Geumdo ended up here, in the Yellow River? Now I understood.

With that appearance, it was no surprise.

A golden turtle—anyone would lose their mind at the sight.

Even if it wasn’t real gold, a shell from a long-living golden turtle would be seen as a priceless medicine by anyone.

I nodded and spoke with a trusting, sincere expression.

“Elder Geumdo, if you’re willing, why don’t you come with me? Of course, I’ll treat you, but you’ll still need care afterward. You’ll need a clean place to recover, and someone to help maintain your health and large body.

I have no other intentions.”

And truly—I didn’t.

I had no selfish motive in inviting Elder Geumdo.

I simply wished for his recovery.

This was entirely for the patient’s healing and the elder’s wellbeing.

Elder Geumdo blinked his large eyes once as he looked at me, and then spoke.

—Brgrr-brgr.

『—Tssrrrt. (If you’d really do that for me, I’d be grateful... but may I ask you just one favor?)』

“A favor?”

At the sudden mention of a request, I perked up and listened carefully.

A golden turtle asking for a favor? That was rare enough to be exciting.

‘What kind of favor? I’m actually looking forward to this.’

As I waited, filled with anticipation, Elder Geumdo nodded slowly and said, with a slightly anxious tone:

—Brgrr...

『—Tssrrr. (It’s just... your eyes reminded me of Hwaseong back in the day, and I wanted to ask—by chance, you’re not going to rub your face against my shell, are you? It really gives me goosebumps... As long as you don’t do that...)』

‘What!?’

My eyes shot open.

That was literally the first thing I was planning to do if he agreed to come with us, and now it was off-limits!

Tang Hwaseong... what a troublesome man.

Had his fun, and didn’t consider the future generation at all!

‘No sense of consideration for those who came after!’

***

With Elder Geumdo agreeing to join us, dawn approached.

Since people were beginning to stir, I hurried back to the inn.

We’d covered the wound with dirt for now.

“So-ryong, do you remember what Elder Geumdo is officially called?”

Once we returned, Hwa-eun asked the question while gazing out the window.

“Of course. I memorized that part of the Twenty-Four Venom Beasts list last time. He's called the Millennium Golden Turtle, isn’t he?”

“Correct.”

The official title was Millennium Golden Turtle.

One of the Twenty-Four Venom Beasts, holding the seat of Yellow among the elemental symbols.

Said to start off the size of a fist and grow into the size of an island—judging by its current size, this was likely its fully grown form.

And with this, my Heaven-Earth-Black-Yellow set of the Twenty-Four Venom Beasts was complete.

Heaven: Flying Heavenly Gentleman

Earth: Earth-Swimming Divine Serpent

Black: Silent Black Noble

Yellow: Millennium Golden Turtle

That made four collected in total.

‘Heh... is °• N 𝑜 v 𝑒 l i g h t •° this a completed set now?’

It felt like filling in a page of the achievements screen.

With a proud smile inside, I said,

“We’ll need to begin treatment first thing tomorrow. He can’t move, so we have to hurry.”

I needed to inspect the wound directly, but since he couldn’t move, there was no time to waste.

But at that, Hwa-eun’s face turned worried.

“But So-ryong... if we treat him at night, what if people see us?

Chipping at his shell will make noise, and if his golden body is exposed, it could cause a frenzy...”

She was right. If Elder Geumdo’s shining golden body became visible, the people of this village would swarm like ants.

Just for a chance to snatch a chunk of what looked like gold.

Whether it was real gold or not didn’t matter.

So we needed help.

Someone who could supply what we needed—tools, herbs—and wouldn’t ask too many questions.

Someone who’d even thank us and hand over money for the privilege of helping.

“I’ve got an idea for that.”

Ding.

I pulled the cord in the room, and a small bell chimed.

When a servant arrived and asked what I needed, I smiled and said,

“This is urgent. Could you summon the Gold Guildmaster? Just tell him it’s very urgent.”

“Huh? Understood!”

The servant, not understanding the situation but hearing “urgent,” ran off.

And a moment later, the Gold Guildmaster himself burst in ahead of the servant, panting.

He didn’t look like he’d just woken up, so he must’ve been up early—but he looked genuinely surprised at the emergency call.

“Y-Young Master So! What’s happened? You said it was urgent? Ah—but you’ve recovered?”

At his question, I smiled and gestured him toward the window.

Then I pointed out the window—at Elder Geumdo, the sand island—and asked,

“If I get rid of that, how much would you pay me?”

Honestly, if I thought about it, this was a golden opportunity:

Treat the Millennium Golden Turtle—

And make a profit at the same time.