At that moment, Sama Hye shot her hand into the air.

“I’ll search the ranches for cows infected with cowpox!”

“Oh, the sooner the better.”

Wasn’t it said that the first step was always the hardest? Encouraged by the atmosphere Sama Hye had created, other physicians began to voice their contributions one by one.

“Then we must first order the warriors to isolate all physicians exposed to the patient.”

“I will prepare tonics. The patient needs strength to endure.”

“We’re running low on soap. I need to prepare a large quantity…”

It was a relief. Jin Cheon-hee sent a look of profound gratitude toward Sama Hye. In response, she mouthed something silently and waved her hand, signaling him not to worry.

He was truly grateful.

It was then.

“Is anyone there! Come out!”

The shout shattered the cooperative mood. The Bandit Suppression Bureau Chief, Ma Jonghak, along with his Head Constables and patrolmen, barged in aggressively. Startled, Jin Cheon-hee turned to find them glaring in his direction with undisguised hostility.

“Visitors must wash their hands before entering,” Jin Cheon-hee said automatically.

But there was no way they would listen.

“We received a report that a plague has broken out here!”

“It didn’t originate here.”

“Regardless, is there a smallpox patient here?”

“…There is.”

But you can’t just isolate them, you fools. We need to perform variolation!

The Empire of Hua had strict protocols for dealing with plagues. Basic measures ranged from quarantine—forbidding infected people from leaving their homes or meeting others—to completely sealing off streets or controlling entire villages. Historically, if the local official in charge possessed a violent temperament, there were cases where the entire village was set ablaze, burning the people to death to cleanse the sickness. In severe situations, an entire fortress might be sealed, paralyzing the surrounding economy.

Regardless of the method, humanity had known for a long time that isolation was the fundamental response to a plague.

They knew. And Bandit Suppression Bureau Chief Ma Jonghak knew this as well.

Ah, damn it. Why here, of all places? The White Qilin Medical Pavilion is favored by Her Highness Ju. What do I do?

Messing with the White Qilin Medical Pavilion and upsetting Wangya Ju would be a political disaster for him. The problem was, if the plague spread and the death toll rose, that would also destroy his future career.

And why does the Young Pavilion Master have to be here personally?

If it were a regular medical pavilion, he could have cajoled or threatened them into submission, but this was the White Qilin Medical Pavilion, and the Young Pavilion Master himself stood before him. They possessed too much political weight to be taken lightly.

Jin Cheon-hee gestured for the Bureau Chief to follow him to a quiet corner, sat him down, and spoke calmly.

“To get straight to the point, the White Qilin Medical Pavilion has progressed significantly in researching smallpox. If you entrust this to us, I believe we can control the spread to some extent.”

“Is treatment possible?”

“Aside from symptomatic treatment, even we cannot cure it. However, I am saying prevention is possible.”

“Prevention is possible? Do you mean variolation? If it’s that…”

Variolation. There was indeed a method to prevent smallpox even in this era. It involved inserting pus or scabs from a smallpox patient into the nose, or wearing the patient’s undergarments to intentionally contract a mild case. While this could prevent future severe infections, because it utilized the live smallpox virus, those with weak immunity often died. Furthermore, there was the risk of the preventative measure sparking the very outbreak it sought to stop.

“Yes, there are cases where methods meant to prevent smallpox actually spread it instead. However, what I intend to speak of is a different method.”

He decided to be honest. Trying to spin it with superstition or mysticism to fit the era would only make things stranger.

“The White Qilin Medical Pavilion has obtained information that those who contract cowpox never contract smallpox again, and we have conducted numerous investigations into this.”

“Do you have data?”

“It is at the headquarters. However, bringing it here would take considerable time.”

“…”

Ma Jonghak fell into deep thought. Orders hadn’t come from above; if he trusted the words of a mere physician and tried to fight smallpox only to fail, he would take the fall alone. His career would be over.

“I cannot permi—”

“Hahaha… Before you refuse, please take a look at this.”

As if waiting for this moment, Jin Cheon-hee pulled out a gold bracelet. The undeniable gleam of the Royal Inspector’s insignia pierced Ma Jonghak’s eyes.

“Gasp…?! Th-That is…!”

Seeing the token symbolizing the Emperor himself, Ma Jonghak hurriedly straightened his attire and bowed low.

“I, Bandit Suppression Bureau Chief Ma Jonghak, greet the Direct Royal Inspector.”

“I… intended to avoid using this if possible. I apologize.”

Jin Cheon-hee spoke with a genuinely regretful expression.

“If you follow my instructions and we fail, the responsibility lies with me. Do you understand, Chief Ma? If there is censure later, you may simply state that it was done under the sole authority of the Royal Inspector.”

Jin Cheon-hee’s expression wasn’t arrogant. Rather, he looked as anxious as a man who had just maxed out a high-interest credit card.

“Will you help me?”

The Bureau Chief bowed respectfully, his earlier arrogance completely evaporated.

“Please give your command!”

“Haa… Yes. Um… Please do not tell the constables. You may include it in the official report later.”

“Yes!”

Now, the die was cast. Ma Jonghak could do his job using Jin Cheon-hee as his shield, and if Hangzhou went to the dogs, it would be Jin Cheon-hee who paid the price. That Golden and Silver Highnesses (nickname given by Jin Cheon-hee) weren’t the type to say, ‘Hohoho, right. You made a mistake with the lives of my people? Let’s do better next time,’ and let it slide.

“While we’re at it, send me a few scribes.”

“For what reason?”

“Since it’s come to this, we must record whether cowpox can treat smallpox and leave it as a treatise.”

If he was going to gamble, he might as well go all in.

***

The priority was to buy a cow infected with cowpox and immediately inoculate the exposed physicians. But the White Qilin Medical Pavilion physicians, who had only learned to treat humans their entire lives, found themselves at a loss on how to acquire such a beast or even confirm the symptoms.

Thinking they should head to the cattle market first, the physicians went out in small groups. Then, they suddenly ran into a familiar face from the slums.

“Honestly, we’ve never done anything like this. How about asking someone who lives here about cows?”

At a Senior Physician’s suggestion, the Intermediate and Junior Physicians nodded. They stopped a local man and explained the situation. He nodded immediately.

“A cow? Of course, I’ll help. Hey! Cheol Meok!”

“Whaaaat?”

Someone stopped moving cargo and ran over from afar.

“The Divine Physician needs to find a cow with cowpox.”

“What? Then we gotta find one. Ah, but that means going to the cattle market… That place will cut your nose off with your eyes open. I wonder if they can manage.”

“Wouldn’t it be better to introduce them to a place that raises cows with cowpox?”

“Right. That’d be better~”

The slum residents chimed in, putting their heads together to debate whose cow had the pox or if risking the market was the answer after all. They looked as serious as if it were their own family business.

Eventually, a conclusion was reached.

“How many do you need?”

“We need one immediately, but the more the better for later.”

“Here, my grandma has an eye for cows like a ghost. If you go with her, you can’t go wrong.”

“Then where is your grandmother…”

Just then, a young man from the slums came running, carrying an old woman on his back.

“Cheol Meok’s grandma has arrived!”

Waaaaah!

“No, why are you crazy bastards screaming in broad daylight? Bullshit.”

The grandmother spoke through a mouth missing several front teeth, her voice rasping with age.

“Why buy a cow with cowpox? You should buy a healthy cow. Are you determined to get scammed?”

At the grandmother’s scolding, the physicians spoke urgently.

“We need a cow with cowpox to prevent smallpox.”

“Cowpox…? Smallpox? Why that…”

The grandmother thought for a long time, her wrinkled eyes squinting at the past, before she spoke.

“Ah… Come to think of it, I had cowpox when I was young, and smallpox never came near me. Same with Seo Hang next door. That… there was talk long ago that getting cowpox prevents smallpox, but no one believed it, so I forgot too. But the young physician lord knows that?”

“The Young Pavilion Master said it was necessary.”

“Huh…”

Intelligence finally returned to the grandmother’s dim eyes.

“That child needs it…? Then we must find it. What do you need?”

One physician offered his back in haste.

“I will carry you from here.”

“Aigoo, I’m heavy, how could you…”

“It’s fine.”

As the grandmother was piggybacked by the large physician, she began to plot.

“I just need to make sure you buy a cow with cowpox cheaply, right?”

“We need to buy it quickly.”

“Quickly?”

The grandmother fell into thought and said, “Then we should ask Chil Deok’s neighbor. That family said they needed money anyway, so if we talk well, we can buy it cheap. Chil Deok’s family is well-off, so they live far from here.”

“That’s fine.”

They hadn’t expected to meet a cattle expert in the slums. The physicians marveled inwardly.

The grace we showed the Gangho returns like this.

Mixed in the group were physicians who had badmouthed the slum people behind their backs in the past. Ashamed, they couldn’t lift their heads, their faces flushed with guilt.

It was a grateful thing. Truly grateful.

Just then, a hulking young man spoke up.

“Aigoo, the physician lord can’t even carry one grandma properly. Give her here!”

He forcibly took the grandmother onto his own back.

“Th-Thank you. Thank you.”

“Carrying a person isn’t about strength, it’s about technique. If you carry her like that, your back will give out. You call yourself a physician and don’t know that?”

“Ugh, you rascal. The physician lord’s back was prettier than yours, so I liked it.”

“Grandma, stop acting your age! Seriously!”

Grumbling, the youth took the lead. The physicians followed, tearfully grateful for the sight.

***

The inoculation itself using cowpox was simple. One just had to make the patient contract cowpox.

In the writings of Teacher Jeong Yak-yong, it was written that one should scrape the cowpox lesion on a cow with a needle, prick the human arm with it, and then rub the cow’s pus or scab over the wound. In some places, they cut a cross shape with a knife and rubbed the pus and scab into it. Of course, this method required caution against other infections like tetanus, but either way, it was something fully possible in this era.

Jin Cheon-hee improved upon this slightly by preparing several needles with forked tips. These were similar to the bifurcated needles used for vaccination in Earth’s history, and the people of the Medical Pavilion called them ‘Preventive Needles’. They weren’t hard to make, and the price was cheaper than syringes, so the cost was reasonable.

I’m worried if this will be accepted.

Even in Korea, where this method was known, variolation—specifically the cowpox method—had faced major setbacks due to the persecution of Western Learning. England, which developed the cowpox method, was the same. Despite discovering the cure first, there was a reason England remained the number one country for smallpox outbreaks for so long; fear and tradition were difficult diseases to cure.