“Broth,” I ordered.

Beside me, Slime-bro immersed himself in the liquid that Aksal had managed to stitch together: a mix of his so-called ‘magical fertiliser’, bits of mashed-up-cooking ingredients, water, and a healthy amount of sugars and salts. Within moments, he swelled up, expanding in size, before hopping out of the bucket and into a nearby beaker.

He glanced at me with a questioning look in his eye.

“Go for it,” I said, nodding.

He concentrated, his body tensing up fractionally – and then, just as quickly, a hole appeared in his side, Slime-liquid flowing out of his body and into the beaker. Once his body shrank to half-size again, he sealed it shut on his own, with far greater expertise than what he had been capable of this afternoon.

Slime-bro truly is intelligent, I marvelled.

The backdoor to Aksal’s store opened, accompanied by the sound of a low bleating of sheep. Right on cue.

“Eric! Explain to us what is going on!”

“Soon,” I promised. Right now, I had to focus. Once the first cultures were set up, there would be plenty of time to talk.

Just minutes ago, I had begun reorganising the interior of Aksal’s workspace. I moved some of his existing alchemical equipment aside, placing just what was necessary for my work. The plan was simple: I would go with a modified version of the vaccination method first pioneered by Pasteur, who had taken samples containing the rabies rhabdovirus from the saliva of rabid dogs, and infected rabbits with them multiple times, before finally using the resultant strain as a vaccine.

Likewise, I had instructed for Aksal to find me some non-human mammals to infect. Here, in the village, sheep were plentiful.

I wasn’t worried about the possibility that he might spread the infection if he left his store, despite his fears – unlike the recent coronavirus pandemic that had occurred just months before I found myself transported to Vergence, there was almost zero possibility of non-symptomatic transfer of poxviruses. It was why smallpox had been eradicated in the first place, because everyone who was capable of infecting someone else had the characteristic lesions on their skin, allowing for identification of contagious individuals and for ring vaccination epidemiological control steps and effective quarantine measures to be put in place to limit further spread.

The theory of what I wanted to do was simple, and blindingly obvious in the world of today, but was considered a truly pioneering and risky venture in Pasteur’s time, when the concepts of viruses, immunology, or evolution hadn’t truly taken hold. The principle was that by infecting an animal of a different species from where the virus normally caused a pathological state, the resultant viral progeny would evolve to become more virulent in the new host, and less in its previous host. Live attenuated vaccines, they were called.

Back on Earth, this theory had been extended to many other viruses, most notably measles, mumps, rubella, polio, and the yellow fever virus. It didn’t matter whether this putative smallpox was magical or not: from what I had seen, magic could occasionally transcend the rules of biology, but it was a temporarily, fleeting thing, as in the case of the burst of heat evolved from Fire Eel flesh. It couldn’t escape the slow and steady hand of evolution.

“Keep the sheep still,” I said succinctly, and Aksal obeyed obediently, although he was clearly bewildered at my actions. Grabbing a scalpel, I slit its internal jugular vein while it stayed in Aksal’s firm grip, letting its blood freely drain into a bucket.

It was my first time killing anything larger than a mouse, but oddly enough, it didn’t bother me all that much. I was focused, my mind set on the experimental protocol I had ahead of me. I could see all the steps that lay ahead, and I was moving in accordance with that.

It was simple logic: this had to be done, or it wouldn’t just be Arlett that might lose her life. Chances were that I, Aksal, and Prisca had already been infected, and so logic dictated that I proceeded as planned.

“I have the jelly ready,” Prisca said, having been assigned to preparing the agar from Slime-liquid earlier made by Slime-bro. “I don’t understand what you’re doing, but… you’re sure this will save Arlett?”

“Yeah,” I said distractedly, gently taking the plates of culture agar and laying them out. “I know you have questions – and you too, Aksal – but back in my world, this Blighted Curse of yours was something we first managed to reproducibly and systematically treat about two hundred years back, and eradicated forty years ago.”

“You can cure it?” he gaped. “Wait, laddie – what do you mean your land eradicated the Blighted Curse?”

“We called it smallpox, actually – just a moment,” I said, grabbing hold of a needle and ladle, the most suitable lab equipment I could find. “Prisca – hold Arlett still for me, please. I need a sample.”

She held the infant in her lap, confused and a little hesitant, but ultimately decided to trust me. I didn’t know whether it was because she believed in my words, or because she didn’t have any other hope since both alchemy and the [Clerics] couldn’t cure the viral infection, but whatever the reason was, it scarcely mattered to me. Arlett was in a restless sleep, shifting agitatedly, but I wasn’t stupid enough to think that I could obtain a sample of the virus without rousing her awake.

Carefully, I punctured one of the small papules on Arlett’s skin, a mildly viscous fluid leaking out. No pus yet, which was good - it was still early in infection, and hence there was no gross inflammatory exudate.

Immediately, she burst out into a shrill, loud cry. Wincing at the noise, I quickly smeared the back of the ladle across the fluid. I heard Prisca trying to calm her child back down, but I couldn’t spare the mental space to pay attention to that any longer. I needed to get the cultures started as soon as possible.

I cut away thin sections of skin tissue from the sheep, placing them in dozens of separate petri dishes that each had an agar base. Normally, growth of an explant by spreading would take place over the course of days, but [Bio-Acceleration: Tissue Culture] could compact that to within a matter of minutes. In front of me, there was a faint growth of the cell monolayer across the agar surface, almost invisible to the eyes.

I could feel my mana draining, as I pushed the skill harder than I did with the Slime membranes. Even then, however, it didn’t tire me out that much. From my estimate of the mana I thought I had left, I felt like I could continue on for a few more hours.

That was good, because I estimated that I would need to do something like this at least forty more times if I wanted to create a strain that posed minimal risk of causing symptomatic disease. The goal was for the final virus to be capable of infection, but still have greatly reduced virulence, which meant a prolonged period of serially infecting these sheep tissues, collecting the released viruses, and then infecting more of them until the virus adapted.

“That’s your skill?” Aksal spoke abruptly, while the cells continued to spread. “I… what is that?”

Of course, something like the concept of cells was incomprehensible to them. All they could see was a faint, reflective sheen as the thin, nearly transparent layer of cells grew out across the agar.

“I’ll explain later,” I said impatiently. The first cultures had grown enough, and so it was time to infect. I placed the other dishes of sheep tissue aside, scraping the back of the ladle across the agar of the first plate. To be safe, I activated [Bio-Analysis], looking to see if the viruses attached to the sheep-derived cells and properly infected them.

Satisfied that they had, I accelerated the growth of this culture, hastening the viral life cycle within the individual infected cells. Oddly enough, the drain on my mana felt more intense for this process than it had been with just the sheep tissue alone. With the Slimes, the mana expenditure had been near negligible, to the point where I could concurrently have hundreds of cultures under the effects of my skill.

Why, though? Was it because it was more metabolically demanding for the individual cells now, as viruses usurped the cellular metabolic machinery? Or was it because this was a more unfamiliar task to me, given that viral growth was slightly different from what I had previously done with Slime membranes?

If mana interacted with biology… the virus would be using up cellular metabolites at a greatly enhanced rate. Was mana substituting for the normal cellular substrates – ATP, nucleotides, amino acids and more – and altering reaction kinetics to hasten the viral replication process? If so, it agreed with the fact that my Slime membrane cultures had been virtually costless, since I had been using their own broths as culture media, growth conditions that were as close to perfect for that cell type as there ever would be.

In that case, then, was mana expenditure directly correlated to the complexity of the task? It was difficult to tell, because unlike a video game, there was no notion of ‘MP’, ‘SP’, or whatever nomenclature was used to denote mana quantity. All I had was a vague sense within me, in the same way that I might know whether I could carry on with another set of exercises in the gym.

I didn’t know. What I knew was that while the normal viral life cycle within the cell might take hours to days, I could probably accelerate my cultures enough to achieve the same result within a matter of minutes. For now, that was what mattered most.

Finally, with all the reagents prepared, I could afford to take a short rest, while the first round of viral infections proceeded.

I wiped beads of sweat off my forehead – had it been that tiring? I hadn’t even noticed.

“I’m beginning the first passage now,” I told Aksal. He’d been watching quietly the whole time, and at last I could begin some explanations.

The question, though, was where to start?

To even begin to understand viruses, I had to explain infections and pathogens. That required an understanding of germ theory. Germ theory built upon the fact that there were biological causes of diseases, rather than curses or hexes that altered existing normal physiology. The primordial thought behind disease transmission used to be the notion of miasma, or ‘bad air’, emanating from rotting organic matter, but that was still built upon the basis that biology could naturally go wrong without the influence of magic.

They knew of poisons, at least. That seemed a good enough place to start.

“In my world, we didn’t have magic,” I began saying. “Even then, in the past, people used to think that diseases like your Blighted Curse were caused by magic, or hexes, or some divine punishment by the Gods. Without magic, we couldn’t simply heal ourselves through a quick skill from a [Cleric] or by drinking an [Alchemist’s] potion.

“Instead, we sought to learn just what it was that made people sick. How do our bodies work? Why do things go wrong? It took us thousands of years, but eventually, we learnt a lot more about ourselves. We learnt what it was that kept us alive, and how we could keep it that way – all without magic.”

I glanced at the petri dish, performing a quick [Bio-Analysis]. The first replication cycle was about halfway done. Soon, I’d be able to harvest the virions, and seed the infection into another dish of intact sheep tissue.

“Smallpox… this Blighted Curse of yours… there are historical records of people suffering from ailments matching its description dating back to more than two thousand years ago. It was only forty years ago that it was declared eradicated,” I said. “Back on Earth, I was an immunologist. People like me studied how our bodies fight back against things like smallpox. I’m sure that even on Vergence, there are cases of people who are infected with the Blighted Curse, but manage to pull through and live?”

Aksal nodded slowly. “We call them the Repentant,” he finally said. “They, who suffered through the punishment of the Deities, live by their grace, bearing with them forevermore the marks upon their skin as proof of atonement.”

Pockmarks of survivors. It was interesting how this society attributed meaning to them. Perhaps some cultures in the past did that back on Earth, too.

“It took us a long time to advance our understanding of it, but eventually, we learnt that your Blighted Curse and my world’s smallpox are caused by something we called a virus,” I said. “Think tiny, invisible little things that attack your body. We learnt just why some people might survive it, and some didn’t. Even before we knew what it was, we observed that those who had the disease once never suffered it again.

“It’s really difficult to explain… but think of what I’m doing here as creating a weak form of the Blighted Curse, and teaching your body to fight off the real thing that Arlett is facing right now. In the same way that someone might become resistant to the effects of a poison after dealing with a low amount for long enough, smallpox can be destroyed by our own bodies.”

I glanced at him, noted his expression, and gave the barest of smiles. “You don’t believe me at all, do you?”

Aksal, who had always been amiable and friendly, was looking conflicted, filled with bewilderment and disbelief.

“I don’t blame you,” I continued on saying, returning to my work. “Heck, back on my world, the pioneers of the field were laughed at for saying such foolish ideas, even though they had the evidence to back it up.”

This was part of the reason why despite knowing how much knowledge of Biology would be helpful to the populace of Vergence, I had no intention of actively taking the time to try and spread what I knew about the subject. Beyond the fact that it would detract from my actual scientific work, my ideas would more than likely be met with flat rejection at first, if not for a prolonged period of time.

Changing such mindsets took plenty of time and effort, as the tragedy of Ignaz Semmelweis, the father of antiseptic procedures, bore testament to. In his life, despite demonstrating that hand-washing and application of aseptic technique lowered mortality rates in medical procedures, he never lived to see the fruits of his labour come true. Hell, he had been driven near-insane, and thrown into an asylum.

Some might call me selfish – but I had no intention of following in his footsteps.

All I wanted was to research and sate my own curiosity. Despite what it seemed, I had no grand ambition to take it upon myself to personally eradicate smallpox here. The first concrete effort to systematically eradicate smallpox globally on Earth began in 1950, and it was only in 1979 that smallpox was eradicated. That was even after considering that vaccination, and the practice of variolation before that, had already been well-established in Europe by that time, and that the Earth had been far more well-connected in the fifties than Vergence currently was. The logistics had been in place for monitoring and distribution of the vaccine, and they had far more talented immunologists and epidemiologists than me.

Altruism was one thing; pragmatism was another. To even try to eradicate smallpox here would take a Herculean effort. I wasn’t naïve enough to think that I would have that many decades to spend on such a task; not if I wanted to continue on with my research.

What mattered here was for Aksal to tell me what he knew about the processes involved in alchemy, and the properties of the reagents he used. For that I needed results. He could have the smallpox vaccine if he wanted; I’d clap him on the shoulder and wish him good luck with his quest to rid the world of the disease. Perhaps wrangle a bit of gold off him to fund more research, but that’d be a bonus.

“How about a trade, Aksal?” I proposed, my back turned to him. I walked over to another corner of his workspace, where Slime-bro was sitting in a nutrient mix. “If I cure Arlett’s Blighted Curse, will you tell me about your alchemy?”

Behind me, there was silence for some time.

“If you really can do what the [Clerics] cannot, lad,” he finally said, and I craned my neck to glance at him. He bore a grave expression on his face, but there was just the slightest of smiles there. “I won’t stop at just that, I’d petition the Alchemist’s Guild to tell you everything you wanted to know. The records there would reveal far more than what little old Aksal could offer you.”

…there was an Alchemist’s Guild? Now that was something I had to see. It had been far too long since I’d been a part of any scientific society, never mind a symposium or conference. What kind of discussions and knowledge would be held within the guild? How different would it be from what I was used to?

“I’ll take that as a yes to scientific collaboration, then.” I gently removed Slime-bro from his resting place, placing him on the table. “Hey, Slime-bro… you know my 2.5-micron mesh? You’ve seen me use that before, right? Do you think you can shape it?”

What I wanted was to retrieve the released virions from the first infected culture, without retaining the cells originally present there. It wasn’t exactly necessary, per se, just that I’d have impurities in the form of cells and virions that hadn’t successfully infected cells the first time without it. Good scientific practice demanded it.

Besides, Slime-bro had been showing masterful control of his membranes, and I was curious to see if it could be extended to such a use.

He tilted his head slightly, before giving a firm nod. His Slime face scrunched up tight, but within seconds, a small bleb that actively leaked liquid separated from his person. The leak didn’t bother me – 2.5 microns was far beyond the size of water molecules.

I was impressed. He would have had to selectively alter the pore size only at that site, be quick enough to release it from himself without losing too much fluid, and seal up the gap where the membrane budded off from his body all at the same time.

Something definitely had to have changed within Slime-bro. He’d shown capacity for learning over the past week, but this was far quicker than the rate he improved at any other task. Was this magic, too?

For now, though, I had work to do. A quick [Bio-Analysis] confirmed that the pores were exactly 2.5 microns in size. Gratefully, I placed him back into his bucket of nutrients, and returned back to where the first viral culture was now ready to be harvested. I added some water to the dish, swirled it about, and poured the supernatant that contained detached cells and released virions through Slime-bro’s shed membrane, where cells were trapped on the mesh while virions freely flowed through the pores.

With a second fresh ladle, I dipped it into the collected flow-through, then brushed it against the second plate of cultured sheep skin tissue. The virions on the ladle were transferred to the second culture, beginning the infection process anew. Again, I repeated [Bio-acceleration: Tissue Culture], hastening the viral replication cycle many-fold.

That marked the start of the second cycle. My plan was for 40 cycles in sheep tissue, back-crossing against a sample grown from myself every 5 cycles to confirm that human infectivity remained intact. At that point, serial passage should have been enough for sufficient mutations to have accumulated for adaptation to infection of sheep cells, and allowing it to be used as a live attenuated vaccine.

If every cycle took somewhere in the range of ten to fifteen minutes… that meant I’d have close to eight hours or so to wait.

Pretty amazing, considering it would probably take weeks if I wanted to do the same thing back on Earth. That was even assuming everything went perfectly as planned, and every good scientist knew that that was never the case.