The Blood-Demon's Bastard

The child’s name was Erika. Eri for short. I only learned this after she was forcibly dragged into my clinic by Wangcho’s rough hands and I managed to bribe her with a few pieces of bread.

“*Munch, munch.* It’s not candy, but it’s tasty, so I’ll let it slide.”

“So, Teacher. Are you saying this kid isn’t actually a Blood-Demon?” Wangcho asked, arms crossed, looking skeptical. Eri, sitting on the examination table, was still gnawing on the bread with eyes full of wariness.

“She’s not a Blood-Demon; she’s a patient. The diagnosis is Paroxysmal Nocturnal Hemoglobinuria (PNH).”

“Is that some kind of magic term?”

“Something like that.”

I assembled various ways to explain PNH in my head. An autoimmune hemolytic disease where a mutation in the red blood cell membrane makes them vulnerable to complement... Hmm. No matter how I thought about it, she wouldn’t understand. So, I gave her an intuitive analogy.

“It’s a ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠disease where the blood breaks down inside your body.”

“Blood can break?”

“Just know it that way. That’s why you have dark urine when you wake up in the morning. The blood is leaking out into your urine, so you’re becoming deficient.”

I gestured with my chin—or rather, my beak—at Eri, who was munching on her bread diligently. “Just as a beast instinctively licks rock salt when it lacks minerals, this child instinctively sought out pig’s blood because she was deficient.”

This symptom is called Pica. When humans are iron-deficient, they try to put anything in their mouths; usually, it’s dirt, ice, or raw rice. For this child, the object just happened to be blood.

“Haa... Tsk, tsk. And here I was, not knowing that.” Wangcho clicked his tongue. The realization that the child he thought was a monster was actually a pitiful patient seemed to touch the last remnants of his conscience.

Just then, Eri, still chewing her bread, asked me a question.

“Mister.”

“Call me Teacher Schnabel.”

“Doctor guy.”

Geez, this kid really can’t get her honorifics straight. I sighed and replied, “Fine. What is it?”

“How did you know the color of my pee?”

Eri’s red eyes stared right through me. “Can healers know the color of someone’s pee just by touching their belly and flipping their eyelids?”

Oh. I was inwardly impressed. She had accurately pinpointed the leap in logic in my diagnostic process, which Wangcho had simply accepted as a matter of course. She’s sharp.

Confirming PNH based solely on anemia, jaundice, and an enlarged spleen is a logical leap. It could be cirrhosis, leukemia, malaria... there are too many candidates.

“You’re smart.” I reached out and patted Eri’s messy hair. The child flinched and hunched her shoulders, but she didn’t dodge my hand.

“Actually, I was just lucky.”

“Eh. Disappointing.”

“Deduction is a series of throwing darts at a target, aiming for the highest score where the answer is most likely to be. In the end, the essence never strays far from luck.”

Anemia. Jaundice. And Pica. These three alone aren’t enough to narrow down the candidates perfectly. But I had another clue.

“Wangcho told me.”

It wasn’t Erika, but Wangcho who reacted to my answer.

“Me, sir?”

“Didn’t you say she ‘comes to drink blood every night’?”

‘Comes to drink blood every night.’ That meant the child’s anemia was likely worsening at night. If I built a hypothesis from there, everything fit together perfectly. There were no glaring contradictions in this hypothesis. If so, you just have to go for it. That is deduction.

“How about that?”

Eri’s mouth hung open at my explanation. It must be fascinating, since I was reciting it as if I’d been watching from the sidelines. Seeing that look, I felt it was worth making a bit of a stretch in my reasoning.

‘This is why medical history is important.’ It’s not for nothing that they say it’s important for a doctor to listen to the patient. A small difference in words can become the decisive clue. Well, I was a trauma surgeon, so I rarely had to listen to patients, though.

‘Honestly, it was luck, though.’ In fact, if her morning urine color had been normal, I was planning to naturally move on to another question. My next candidate would have been asking if her stomach hurt. Thanks to the power of the ‘misunderstanding trope,’ I managed to hit the mark on the first question.

“Does that satisfy your curiosity?”

After my explanation, a silence fell. ‘How about that? Pretty cool, right?’ Don’t I seem like a genius? Like Sherlock Holmes? While I was inwardly patting myself on the back, Eri nodded blankly. Wangcho burst into admiration on her behalf.

“Haa... As expected of the Teacher. Now that you mention it, it all fits perfectly!”

Wangcho clapped like a seal, his eyes shining. This is why I like Wangcho. His reactions are top-tier. Yeah. Clap more. I’m the protagonist. I’m Dr. Schnabel.

“Now that you know the cause, is it possible to treat this child?”

At Wangcho’s question, Eri’s head snapped up. In those red eyes, which had been filled with resignation and distrust, I felt a spark of hope for the first time. There was an expectation that if a doctor had unraveled the curse that had been tormenting her, he would surely have a solution.

Receiving their burning gazes, I replied nonchalantly.

“It’s impossible. It’s an incurable disease.”

“...Excuse me?”

Their expressions froze instantly.

PNH. Paroxysmal Nocturnal Hemoglobinuria. I don’t know if I remember this accurately because I was a trauma surgeon in my past life, but I remember the injections to treat this disease were incredibly expensive. Was it Solaris? I remember it being a crazy injection that cost about 500 million won per year. Even the cheaper ones were around 300 million won per year. I remember it because they said it was in the lineup of the world’s most expensive treatments. I think they said it was even more expensive than cancer drugs.

Naturally, I don’t know the ingredients, let alone the components of these treatments. And there’s no way I could reproduce them in this world. So, I said it honestly.

“It’ll probably be difficult to cure the disease right now.”

“...I see.”

The light faded again from Eri’s eyes as she nodded. The resignation that had been underlying those red eyes, which had held hope just a moment ago, returned.

At that moment, Wangcho tapped my shoulder with his finger in a hurry.

“Teacher, watch your words!”

“?”

“Didn’t you say the same thing during my gout treatment?”

“Did I?”

Wangcho clutched his forehead at my reaction.

“That habit of saying ‘it’s an incurable disease’ right off the bat, and only adding ‘you can take medicine’ much later! That’s a really bad habit!”

...Have I done that? Now that I think about it, I think I have. I think I was even pointed out for this by my seniors and residents in my past life.

— “Yunho! Stop telling the guardians the bad news first! You’ll give them a heart attack!”

— “Professor. I think you omitted the object again.”

Geez. Am I wrong? But from a doctor’s perspective, it’s correct to say it’s an incurable disease if it is one. Treatment and management are strictly different concepts. Just like no one in this world says they can ‘cure’ diabetes, it’s just a disease that needs to be managed.

“I can’t lie to the patient.”

“This is why geniuses are! But there’s an order and arrangement to speaking! If you say the conclusion first, ordinary people like us can’t keep up with you!”

Wangcho sighed. But I had a lot to say about that part, too. I was taught in school to give patients as little false hope as possible. There are no people who resign and sue, but there are many who sue out of a sense of betrayal. That’s why I tend to deliver the bad news first, but that’s usually just the conclusion.

Unaware of my inner thoughts, Wangcho turned his head away from me and crouched in front of Eri.

“Kid. You understand. That teacher is just like that.”

As his large body folded, the hyena beastman’s golden eyes became level with Eri’s red ones.

“I’m the same as you. I have a disease that doesn’t get better, but as long as I take my medicine, there’s no problem living my life.”

Wangcho looked back at me. “This kid is the same, right, Teacher? There’s a ‘but,’ right?”

It was in the form of a question, but it was closer to the nuance of ‘there better be a but.’ Under that silent pressure, I folded away the ‘180 principles of why PNH is incurable’ I had been organizing in my head and delivered the conclusion.

“As Wangcho said, you’ll likely have to live with the disease for almost your whole life. But I will give you back your daily life.”

I can’t cure it completely, but I can manage it. Actually, your daily life will be less problematic than it was with gout. Wangcho was relieved by my definitive answer. The light returned to Eri’s eyes. In addition, a slight dissatisfaction was visible. She seemed to be sulking, perhaps thinking I had played with words on purpose. I could tell without even needing to read her expression, as her lips were pouted out quite a bit.

I pushed her lips in with my finger.

“First, let’s check your blood. The symptoms are typical, but I have to confirm.”

I turned and took out tools from the examination table drawer. Wangcho looked at me, puzzled by my actions.

“What else do you have to test?”

“Didn’t I tell you? Deduction ultimately relies on luck. Unless it’s 100%, diagnosing based solely on symptoms is dangerous.”

If you suspect a disease, you have to test for it. The tools I took out of the drawer were none other than a glass, vinegar, and a syringe. I held the syringe and gestured to Wangcho. As if they knew what to do, Wangcho grabbed Eri’s arm.

“Stay still.”

Wangcho covered Eri’s eyes. In the meantime, I quickly drew blood.

“Wangcho. Press it firmly. It’s a disease where hemostasis doesn’t work well anyway.”

Wangcho pressed Eri’s arm firmly with cotton. Meanwhile, I divided Eri’s blood into two glasses. Then, I dropped a few drops of vinegar into only one of the glasses.

Ham’s Test (Acid Hemolysis Test). It’s a test that utilizes the fact that PNH red blood cells are easily ruptured by complement attack in an acidic environment. The result appeared immediately. The blood without vinegar remained red and cloudy. But the side with the vinegar...

“Ohh...! The color...!”

It turned into a clear, transparent grape juice color. It was a hemolysis (red blood cell rupture) reaction so stark that even Wangcho, who was ignorant of medicine, could tell immediately.

‘Ta-da~ Magical.’ If it weren’t for my character, I would have rattled on like this. Instead, I patted Eri’s head, telling her she endured it well. Eri stared blankly at her own blood, which had turned transparent.

“This is... what? Magic?”

“Let’s call it a trick rather than magic.”

I prepared the next step. Since the diagnosis was finished, I had to prescribe. ‘I can manage it if I do a blood transfusion.’ Even if PNH can’t be cured, it’s a disease that can be managed to some extent with blood transfusions. However, before doing a transfusion, I needed to find the most suitable blood. I pricked Eri’s finger again to get blood. And I took out the blood samples I had kept in advance. To be precise, they were the ones collected this morning. Since I didn’t have the technology to store blood, it was my habit to receive enough for the next day from a few people whenever they came for treatment.

“Wangcho, I’ll borrow some blood.”

In addition to these samples, I added mine and Wangcho’s blood to them and mixed them with Eri’s blood.

“Hmm...”

Conclusion. As a result of the Cross-matching test, Eri’s blood type matches mine.

“Right. Let’s do the transfusion when the blood is ready the day after tomorrow. Until then, just control your nutrition at the clinic for the time being.”

“Trans...fusion?”

Eri tilted her head at the unfamiliar word. I left her alone and said to Wangcho,

“Take care of Eri. Until the transfusion in two days.”

Wangcho nodded.

***

Two days passed, and the promised date arrived. In the meantime, washed red blood cell preparations were completed with 200ml of my blood. The reason I processed it into washed red blood cell preparations was that if a PNH patient receives blood as it is, a hemolytic crisis can occur. However, the journey to make this preparation was a bit complicated. Drawing blood, making Wangcho’s subordinates spin it around tied to a string to separate the heavy and light parts, throwing away the light side, rinsing it with salt water, spinning it again, rinsing it again...

‘I knew it, humans really did build the pyramids.’ Sufficient labor can replace technology. And that labor can somehow be bought with sufficient capital. According to this formula, if you know the principles, you can reproduce 21st-century medicine to the level of 19th-century civilization.

‘It seems to have been completed well.’ Just in case, I shone the washed red blood cells under the magic stone lamp. A clear and clean red color. Pass.

“Alright. Let’s start.”

I laid Eri on the examination table. Thanks to feeding her for two days, there was a bit of color in her face. That’s the natural result if you feed her that much iron-rich food. Any beast becomes gentle when its belly is full. Unlike two days ago, Eri, whose personality had become rounder, asked,

“...Does it hurt?”

“It’ll sting a little. But bear with it.”

I stuck the needle into Eri’s arm. There was no amateurish mistake of searching for ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠the vein multiple times. I’ve lived off surgery for a long time, after all. Finding veins is something I can do even while dozing off. The red liquid flowed slowly into Eri’s veins. One minute. Five minutes. Ten minutes.

“....”

Eri was staring blankly at the ceiling.

“How do you feel?”

“...I’m not sure.”

No problems. Check. “If you feel dizzy or short of breath, tell me.”

Come to think of it, it’s been a really long time since I’ve done a blood transfusion myself. After finishing my residency in my past life, I never had to find veins. The residents or nurses did it all. An hour passed ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠like that.

The transfusion ended safely. 200ml. It’s not a large amount, but it was enough considering this child’s physique.

“Rest well today. Let’s decide whether to add more tomorrow after checking your condition.”

Eri nodded. As Eri got off the bed, I asked her for confirmation.

“How is it? Do you still have a thirst?”

“A little less.”

“That’s good.”

Pica is also easy to correct. It’s a symptom that disappears quickly once iron and red blood cells are replenished. In a week, she probably won’t be looking for blood anymore.

“Let’s get regular transfusions like this. You’ll probably be like this for the rest of your life, but that alone won’t interfere with your daily life.”

Of course, it’s impossible to make Eri’s disease disappear just with transfusions. If that were the case, those multi-hundred-million-won injections wouldn’t have been developed. Furthermore, PNH is a disease that requires additional management by a doctor while receiving transfusions. However, I didn’t bring that up in the hopeful atmosphere. ‘Managing those risk factors is something I’ll take care of anyway.’

Living her daily life won’t be much of a problem. Now, she doesn’t have to bury her head in a bucket and greedily drink blood. There will be no reason to be pointed at as a Blood-Demon, and she won’t be kicked by people like Wangcho anymore.

Maybe it hasn’t hit her yet. Eri fiddled with the bandage on her arm. Perhaps still unfamiliar with her body, which had started to circulate warm blood, the child repeatedly clenched and unclenched her fist. Then, she looked up and met my eyes.

“...Why are you doing this much for me?”

“What are you trying to say?”

“I don’t have any money.” Eri muttered in a voice that was fading away. “All I have is these clothes. Mister... no, Teacher Schnabel, I don’t have the ability to repay what you’ve done.”

The child knew the physiology of this back alley better than anyone. There is no favor without a price. Especially in Limbus Pit, kindness without a reason usually demands a more terrible price later on. Distrust and anxiety were visible in her.

Usually, sincerity wasn’t what was needed to clear this away.

“Then run errands for me.”

“What?”

Usually, what’s needed in this case is give-and-take. I pointed to the clinic floor with my finger.

“You have to be managed by me regularly anyway. So, you’ll work here. I’ll take care of your meals and lodging.”

“...Here?”

“I happened to need an errand runner. Receiving medicine, contacting patients, and cleaning occasionally. Can you do it?”

“...Okay. I accept.”

The motion of her nodding was stiff. It was a nod like stamping a seal on a pledge. But compared to just a few seconds ago, her wariness had clearly faded.

‘It’s a strange thing.’ Just by changing a favor without a price into a transaction, a person’s wariness crumbles this easily. Whether it’s zero won or the price of a cup of coffee, compared to the quality of the treatment, it’s practically free, but just by setting up this threshold that’s better than nothing, the reaction changes. They said it’s like that in Korea, too.

“Wangcho.”

After finishing the transaction, I called Wangcho, who had been waiting outside.

“It seems this child will be the new errand runner starting today. Can you tell her what she needs to do? Just like the other kids did.”

“Understood, Teacher.”

Wangcho gave Eri’s back a light push. Eri looked back once as she crossed the threshold. When I gestured for her to go, Eri turned her head and left. As the two of them went out, I was left alone in the treatment room. While organizing the transfusion tools, I ruminated on the conversation from just a moment ago.

— ‘All I have is these clothes. Mister... no, Teacher Schnabel, I don’t have the ability to repay what you’ve done.’

“Well. I don’t think so.”

I muttered to myself, where no one would hear. Erika is evaluating her own value only that much, but my thoughts were different. Now, let’s organize this once. It’s a rare disease. A rare disease that I’m the only one in the whole world who can diagnose. To make matters worse, her blood type matches mine. Even though it’s a disease that requires periodic blood transfusions.

Question here. Would anyone who has read a few web novels consider this child an ordinary extra? No way! ‘Who knows if she’s a dragon that polymorphed somewhere?’ Maybe she’s a future Sword Saint, or a childhood friend who becomes the strongest in the world. In other words, this is an event. A low-point buy-in event.

‘Well, maybe not.’ Of course, she’s not the first child I’ve caught after saying things like this. A year ago, it was testicular torsion; eight months ago, phenylketonuria; half a year ago, congenital clubfoot; three months ago, congenital diabetes... Various children passed through my hands. I treated and hired them every time, and explored their talents. Among them, there was no SSR or 5-star I wanted.

‘Still, the feeling is a bit different this time.’ It’s just something different. It’s hard to explain specifically. But what if I say all this and it’s a dud again? It’s just a pity, what can you do. They say you keep holding a rain ritual until it rains, anyway.

‘For now, shall we start with errands?’ Just like the other kids did. If I keep at it, one or two talents will eventually turn up. I hope it’s the talent I want, though.