Erysichthon Protocol (Complete)

Crack. Crunch.

The creature’s beak punched through the window frame. I snapped back to my senses, snatched a dry towel to cover my mouth, and grabbed the metal skewer.

One. Two. Three. I cracked the window open. The thing shoved its head inside.

Thud.

The bird blinked. Its skull was thicker than I expected; the skewer hadn’t punched all the way through. Still, I hurled the whole assembly out before the blood could spill. Then I slammed the window shut.

“Kwaaaaaah! Kiiiaaaaaah!”

Damned crow head. It had finally realized what had been done to it.

Even as it drove the skewer deeper into the dirt, the creature kept flapping its wings.

As if it could still fly. As if it were begging the sky for one more chance. All that pomp for a mere bird.

It finally vomited a stream of dark blood like crushed grape juice and collapsed with a wet thump.

Then the sky darkened.

I glanced up, thinking it was a cloud.

But it wasn’t.

A mass of storm clouds was surging in, fighting the wind, crawling straight toward me. Writhing, squirming, yet stubbornly, relentlessly advancing.

They were birds.

A flock of birds.

A murder of crows that swallowed the sky faster than I could blink.

A living thunderhead that screamed caw instead of thunder and shed feathers instead of rain. The trees were already trembling; they knew what was coming. This clearly wasn’t their first rodeo.

I stepped back from the window and yanked the curtains shut. I gripped my gun and knife tight, pressed myself to the wall. I would not react to the noise. I would only smash anything that stuck its head inside, then retreat deeper into the room.

Caw! Caw! Caw!

The sound hammered my eardrums harder than any earplug could have blocked.

Savage shrieks. Desperate howls. They were the voices of zombies. The frantic beating of wings, the thud of undead bodies slamming into tree trunks as they fled in panic. They traded eyes for wings, flesh for broken beaks.

Sometimes your ears see better than your eyes. This was one of those times.

Sound design is useful in any situation. In a world where every noise is information, where every rustle can be the difference between life and death, my brain had been trained to sort through the chaos. The scene outside was clearer to me than if I had been watching it with my own two eyes.

I had to focus.

I couldn’t afford to chase every single sound. It was like driving. Everything had to stay in balance: how hard you pressed the pedal, when you touched the brake, the movement of the car behind you, the one ahead, when the light would change, whether someone might suddenly dash out from that alley.

If you tried to track every variable at once, you’d have a nervous breakdown. So I kept the whole picture in mind while narrowing my attention to what was right in front of me.

I breathed. In. Out. My mind could not be allowed to wander.

I ignored the wingbeats. I ignored the tapping on the window ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠frame. I ignored the metallic clatter of the skewer falling. I even ignored the fact that another flock of crows was already tearing apart the corpse of ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠the one I had just killed.

Out of the crashing wave of information, I seized one clear thought.

This world’s virus can infect animals, too.

Erysichthon Protocol let players set different transmission vectors for each playthrough. You could even add options that allowed the parameters to change mid-game.

The vectors themselves varied wildly: airborne, waterborne, physical contact, droplet transmission within a certain range, contaminated food. The most vicious settings were “completely random transmission” and “multi-vector infection.” Respiratory and waterborne could be active at the same time. Every vector could be enabled simultaneously.

That was why I needed to know how it spread. ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Only then could I decide what I was allowed to do and what I must never do.

If it was respiratory, I would need a mask at all times and firearms would be mandatory. You had to shoot before they got close. But firing a gun revealed your position, so the entire game shifted toward base defense and territorial conquest.

If it spread only through water, the playstyle opened up dramatically. Boil and disinfect your water and you could survive being scratched or even bitten. In that scenario you could move like a thief, kill like an assassin.

But I didn’t know this world’s rules. Even if the locals had figured something out, I couldn’t take their conclusions at face value. They might have missed critical details. The virus might have mutated since their last observation.

That was why, until now, I had relied on burning the bodies or setting the infected against one another.

And just now I had found another piece of the puzzle.

Zoonotic transmission enabled.

It meant the virus could jump between humans and animals. Pathogens that cross species barriers are notoriously difficult to eradicate.

No matter how strictly you declared a Human Non-Protected Zone, how ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠did you control the birds in the sky? Even if you banned animals from certain areas, how could you stop vehicles coated in the virus from moving freely?

Zoonotic infection made total containment or eradication almost impossible. You could vaccinate every person and every farm animal, but the wild ones would still carry it. The virus would keep leaping across those gaps until it finally breached the immune system.

Yet something even worse existed: infinite mutation. Temporary dominance won through endless competition between variants, followed by inevitable rebellion. Just like the word “temporary” suggested.

Viruses, like humans, will do anything to survive. The problem is they know their odds are low.

So they do exactly what I would do.

Just as I mass-produced traps because I knew zombies rarely fell for the same one twice, the virus never stopped experimenting. It kept mutating, constantly trying to increase its transmissibility and lethality.

After all, there were countless hosts—humans and animals alike. The testing ground was more than sufficient. It was an infinite regression: raise a specimen carefully from level one to the highest level, then send it to the next stage to see if it could survive.

When two regressors meet? They fight to the death, or one consumes the other. The survivor, the one who proved its superiority, becomes the seed of the next generation.

If zoonotic transmission was active, the “rapid zombie-virus mutation” option was probably active as well. The two usually came as a set.

If not, the solution would still be relatively simple.

But if both were on, the destruction of this world was all but guaranteed.

This world’s zombie virus would continue evolving. It would advance just quickly enough to keep pace with humanity’s limits, testing exactly where those limits lay.

And the moment humanity finally showed weakness, it would smash through like a tank through a paper shield. It would never stop. Not until it ruled the world completely.

People cling desperately to life. The virus would do the same. Its survival strategies had already been proven through countless real-world battles.

And I had enjoyed exactly this kind of survival game more times than I could count.

“Either way… isn’t this exactly the kind of game I loved?”

When I thought of it that way, it didn’t seem so bad.

It was a long while before I finished packing and stepped outside. The silence was deep, tranquil, and pleasant.

Just as I had expected.

The birds had stripped the zombies clean. The corpses, now nothing but bones and sinew, lay slumped like puppets with cut strings.

Even the lighter parts—fingers, toe bones—were gone. Only the heavy pieces remained: rib cages, skulls.

Everything else had been neatly devoured. Or carried away in beaks. The cloud of birds I had seen leaving had flown noticeably lower than when it arrived.

I finally understood why there had been no insect sounds in the forest and why the zombies had moved in packs. They had learned that survival required it. Not intelligence. Pure instinct.

Eating is instinct, not intellect. There was no noble zombie philosophy of “strength in numbers.” If blood flowed and something looked edible, they would happily devour the comrade who had stood beside them moments earlier.

It was simply natural law. Like seeking shade from rain, sleeping when tired, eating when hungry. They instinctively knew that gathering in groups raised their individual survival odds. Even with their higher reasoning paralyzed, that automatic survival program continued running.

Humans really are tenacious creatures.

I returned to the container. Everything was exactly as I had left it. I had half-expected at least one looter, but judging by the current situation, surviving alone here was harder than it looked.

Of course, I was not an ordinary man.

Before leaving, I quickly skimmed the forest keeper’s meticulously kept scrapbook. I had brought it hoping for useful information. Even if it proved worthless, it would make good kindling, so I folded it carefully.

The most valuable entries concerned Hampton City—the very place where I was supposed to meet that man named Hans. Since it was the largest city closest to this area, the clippings about Hampton were numerous.

Articles about the relatively cheap old town, the massive corruption scandal that had erupted during postwar reconstruction and forced the mayor to resign.

There was even an article with a red pencil circle around the winner of a children’s speech contest that fiercely condemned violence by Elza Liberation Movement members. Next to the child’s photo were the words Our granddaughter.

Other entries were circled in black with curses scribbled beside them. They detailed the frequent violent crimes occurring on the road between this forest and Hampton. One of them concerned a biker gang.

Combat veterans who don’t do a single worthwhile thing and only waste bullets.

The final article was about the sudden quarantine order. Due to concerns about a recent infectious disease, a lockdown had been imposed on Hampton City.

The fingerprint scanner on the briefcase was still blinking red. If that con artist had been telling the truth, I was currently being tracked. The fact that these messages were reaching me inside a dead zone suggested this phone might have been hacked as well.

Actually, that was perfect. The more public the auction, the higher the briefcase’s value would climb.

Vrrrr.

Right on cue. A new message.