[August 25, 1300 – Terre]
I wake up on a wolf fur bed. It's soft, but not as comfortable as you'd think. It's still a little damp from the night dew sneaking through the gaps in the wooden house. Outside, I hear some bird chirping—a species that definitely doesn't show up in any high school biology textbook. I'm too lazy to open my eyes at first, but eventually I drag myself up.
First thing: brushing my teeth. The toothbrush is made of wood, with bristles from either coconut fibers or some kind of grass—I'm not sure, but at least it works. The toothpaste is truly "organic"—a mashed-up herbal mixture tasting like fresh mint blended with clay. No fluoride, but whatever, my teeth are used to it by now.
I wash my face with well water that I drew up last night, stored in a clay jug. The cold water splashing on my face feels like taking the derivative of sleep itself. After stretching my back a bit—because that bed has zero bounce—I throw on a light cloak and step outside.
In front of me lies a path paved with square stones, each about 25 cm on each side, fitted together like a giant puzzle. This city sits in the western part of Mikhland, a major trading hub, and carries a strong Islamic flair: pointed domes, onion-shaped roofs, stained-glass windows, and rows of pillars carved with a mix of Runes and Arabic script. Everything is so symmetrical I can't help but suspect some geometry-obsessed architect was behind the city's planning.
I walk a few hundred meters—around 243 steps, according to my habit of counting—to a food stall by an intersection. The owner is an old man with gray beard, wearing a turban and speaking a strange blend of Turkish and Old Latin. I nod a greeting, hand him eight copper coins—each coin weighs about 9.5 grams, 2.7 cm in diameter, 0.3 cm thick, I've measured them—and receive my meal.
It's flatbread, a type of mashed beans that tastes like mung beans mixed with sesame, and a piece of grilled meat that I can't quite identify but it's definitely not chicken. I sit down on a stone bench by the stall, eating silently. Nobody pays me any attention—which is exactly how I like it.
Just the morning sunlight, the streets slowly filling with people, and inside my head, numbers quietly shifting.
Like an unfinished equation in a world still looking for its solution.
After finishing my meal, I brush off my hands and head back to my wooden house. On the way, I mutter simple math expressions to myself. It feels weird if I eat breakfast without calculating something.
Once home, I pull a stack of papers from the desk drawer—financial reports from Facility I, the enzyme production plant Aldo runs. Aldo handles the ideas and controls the supply chain, but when it comes to cash flow and numbers... they always land on my desk. He once said, "Math and Minh go together like rice and fish sauce." Sounds about right.
I glance through the numbers.
This week's total revenue: 28 gold coins.
I nod slightly—nice number. But then I look at the profits... only 3 gold coins. I let out a quiet sigh.
Taxes are no surprise. 10% revenue tax, 3% environmental tax. It's the 3% that's annoying. What greenhouse emissions? Enzymes made from fruits, naturally fermented, cleaner than making homemade yogurt. But because "every factory must pay environmental tax," we still have to pay up. Regular as an arithmetic sequence—no escaping it.
And the real reason: Aldo sets the enzyme price super low—just barely above cost. He wants the market to get used to the product first, then raise prices later. I get the strategy, but seeing profits like this... well, the numbers look nice, but my heart doesn't feel great.
I fold the papers and set them aside. It takes me about 20 minutes to run all the necessary calculations—truthfully, mental math is faster than using an abacus at this point. Sometimes, I even take derivatives and integrals just for fun, though they don't really apply to cash flow.
Then I grab a small cloth pouch, stuff in a few coins and my notebook, and step out of the house. Today's lesson is logarithms.
The city library is on the second floor of an old mosque, with a high vaulted ceiling and natural light pouring through stained glass, scattering colorful patches across the room. It's so quiet I can hear the soft flipping of pages from another table.
I find a math book written in the local language but using familiar notation. The content looks solid—seems like a copied version of old Earthling materials. It starts with the basics: common logs, natural logs, base change rules... then moves onto properties.
I settle into my usual corner, pull out my pen and notebook. My handwriting is neat, lines spaced evenly like graph paper. After the theory section, I dive into basic exercises—mostly log transformations, solving for x, that kind of thing. For the advanced section, I pick problems involving hidden variables inside logs, which require switching to exponential form. Honestly, solving logs by hand without a calculator is a bit rough, but I'm used to it by now.
Finally, I pick two hard problems—the kind you'd see in a provincial math competition—though that province is now at least a few dozen light-years away in scrambled time units.
As I write the solutions, the name of the high school I once got accepted into flashes through my mind—the best school in the district.
Back then, when I got the acceptance letter, I imagined myself standing in the school courtyard next to the honor roll board. But before I even set foot in the place... boom, I get summoned here. No graduation, no semesters, no roll calls, no teachers, no school bells.
Just enzymes, environmental taxes, and logarithms.
I look at the page in front of me, frowning slightly.
"That's rough."
But I keep studying. Because math is the only thing I've been able to hold onto, completely intact, from the old world.
I tear my eyes away from the messy logarithm symbols in my notebook and glance out through the arched window. On the golden-brown stone-paved street, sunlight spills down the gentle slope like a smooth gradient, each passerby's footsteps like a data point in some chaotic nonlinear function.
And then I see them—a group of skinny children, their small shoulders straining, each carrying bundles of firewood twice their size. Their clothes... well, calling it "fabric" feels a little optimistic.
A man—dressed in the traditional Islamic style of the Tarif region, with a long robe, a headscarf, and a hoarse, rough voice—shouts loudly at them. He uses a curved stick to jab at the children's legs, making them stagger, one almost falling.
I frown.
Child labor has been banned in Mikhland for a few years now, after a "civilization reform" campaign the nobles bragged about to please their allied nations. Slavery still exists, sure, but children—those not yet of "adult age"—are, in theory, not supposed to be forced into heavy labor.
I remember something Aldo once said: "Fifteen is the age of adulthood here. If you make kids work before fifteen, that's illegal."
But then Joon-soo had argued back, saying something like, "Depends on the region. Tarif usually uses fourteen because their coming-of-age ceremonies happen when boys can wield a sword and girls can cook."... Back then, I just thought of it like how some rural areas in Vietnam let kids start first grade at five while others wait until six.
But right now, I'm staring at a bunch of kids clearly underage... being whipped along with bundles of wood in the street.
I mean to turn back to the half-finished problem in my notebook—a nightmare involving log(cosx), tan(logx), and endless recursive transformations like a reversed series. I'd already torn out a whole page from messing up a single transformation.
But then...
A group of slaves sprints across the street. Running like someone cracked open a door of hope—but so briefly they can't even catch a full breath.
One of them gets struck hard in the shin by a slaver and crashes onto the stone pavement, blood trickling from their forehead.
The guards see it. I think maybe they'll intervene? They do—but not to help the fallen.
They charge in, slam the escaping slaves into the ground, tie their hands and feet with leather straps, stomp on their backs, and drag them away like sacks of grain.
I let my pen fall.
My eyes, without thinking, follow them.
On one person's hand... I catch a glimpse of a small tattoo, a strange symbol I've seen before in the mirror when I first arrived in this world.
Earth slave.
No mistake. That's the identification mark reserved for Earthlings who were illegally summoned and later "owned."
The people just tied up... are my people. They're Vietnamese.
For a moment, my heart freezes.
I recognize a few faces. Faces I glimpsed back when I was living at that farm near the northern forest—the one where so many people fled and then disappeared. And if my memory's right... they're not going to have a good time after this failed escape.
My head starts to ache a little.
The scene in front of me seems to drain of color, turning black and white, leaving only raw geometry—human figures pinned to the ground, leather cords stretched tight, whips arcing through the air.
I stay calm.
I try not to let my face react too much. I close my book, gather my papers, cap the inkwell.
And then I leave the library.
Without saying a word to anyone.
A gentle breeze blows, but it doesn't do anything to ease the tightness in my throat.
I lift my head toward the sky—a brilliant blue, with slow-drifting white clouds, like a derivative-free function. It looks exactly like the sky on Earth.
I stare off into some vague direction, into some undefined distance.
Like the distance between me and my old high school.
Like the distance between me and the friends I used to have.
And now... the distance between me and the people from my homeland being dragged across the stone.
I let out a long breath.
Earth... what time is it there right now?
I stroll down the stone-paved road. The sun is out, but not enough to scorch my skin. The wind slips between a few large-domed Islamic-style buildings, their walls hand-painted with floral patterns, all colored in a hazy desert palette—like a third-degree polynomial that hasn't been normalized yet.
At a hidden corner—where the main street splits into a narrow alley with a Teretian fish sauce shop (yes, really, "fish sauce")—I spot a bunch of guards rounding up a gang of bandits. They wear light armor, panting hard; one of them is still trying to crawl away but gets yanked backward by the collar like a reaction force vector.
I glance over. Arian bandits. Heard about them a few times—mostly known for shaking down elf merchants or illegally selling slaves.
Gotta admit—the Tarif guards are efficient. Over a week here and I haven't run into any crime, except for a few old guys price-gouging at the market. Only now do I get a proper look at what "urban security level: slave state" really means.
I keep walking, mumbling inside my head, watching my steps—this stone is slippery; if I'm not careful, I'll slide like a second derivative losing its extremum.
"What kind of fantasy world even is this..." I think.
Sure, there's magic, there are swordsmen, there are teleport gates. But the vibe? It's not much different from some post-colonial state mixed with fascism. Even the tech is stuck way behind—no phones, no computers.
Yeah, there are non-humans too.
At the slave market, I spot a few elf ladies—around 1.7 meters tall, sharp ears, long white hair, and... well, I'll skip the rest—not really appropriate for a middle schooler like me who's supposed to be busy studying instead of analyzing "space mass."
Then I hear the news—the Tarif authorities announce a case where an elf kidnaps a boy and raises him just to breed later at night... In El'mr—the all-female Elf Kingdom—rumor has it that men there are considered national treasures, worth more than pure gold. Sounds like some fanfic nonsense back home, but here it's an official government announcement, sealed with royal wax and posted right in the center market.
I also once ran into a Succubus. I remember that day clearly—we had just escaped the slave labor camp with Aldo's group, and while walking around, we see this girl with black hair, violet eyes, a short skirt, floating like she's weightless. She smiles at me. I almost step right toward her, if Hai hadn't chucked a flask of HCl straight at the demon's face just in time.
Hearing the Succubus scream and vanish into thin air still sends chills down my spine.
Lately, I miss home terribly.
I miss Vietnam.
I miss the bánh chưng my mom makes every Tết. I miss the old electric fan rattling away during summer naps.
I miss those 2 a.m. League of Legends matches where I screamed over getting a pentakill—even if there was a math test the next morning.
I miss... the world where functions only exist in textbooks, not in how I have to see this messed-up society.
I keep walking, head down. Above me, white clouds drift across the sky, looking like a sine graph sliding out of phase.
I wonder if somewhere out there, someone on Earth is looking at the sky the same way I am?
Still wandering, eyes flicking at clouds, mind drifting between memory and the now, I hear a shout.
"Damn it, stop right there!!"
I whip around. An Arian bandit. Enchanted shoes—I recognize them right away because the heels glow brighter with each step, like an exponentially growing function flipping backward.
He's holding a shamshir—its curved blade twisted like an off-centered square root graph.
He charges straight toward me—not aiming for anyone, probably just trying to jump the street and escape.
In that split second, I remember—the Strays, Aldo's group, and me too—back then we didn't even have a cool name. Just a bunch of runaway kids, stealing food, hiding, faking identities, broke enough to eat rice mixed with wild leaves.
We once wiped out an Arian outpost in central Mikhland. It was a rainy night—I was providing backup, drawing derivative path graphs to guide enzyme bombs Aldo made, while Veritas armored up into a bulldozer charging through. Joon-soo... yeah, that guy was a monster—slicing down from the camp roof like a vector tearing through every resistance.
Back then we were so broke, none of us could afford an inn. That outpost became our home—until we got hunted for, you know, torching someone's base.
The bandit is about to rush past me when—
Swish!
Three guards leap out from the alley like it's all pre-programmed. One draws a sword to block him, one sweeps his legs, and the last one dives to tackle his head.
"Drag him straight to the stone cell!" one of them shouts.
I barely have time to blink.
The bandit screams "You dogs!!" before getting dragged across the road like a yanked, jagged graph.
I sigh. Gotta say, the Tarif guards are impressive—hard-working, fast, and... a little ruthless.
I keep walking. I'm done thinking about fantasy.
My eyes stay on the ground, but my mind drifts back home.
I miss the grassy field behind the school, where we kick around a worn-out ball that Đức "Fatty" digs out from a trash bin. Every afternoon, they call out, "Wanna play?" and just like that, I ditch my homework, slip on some flip-flops, and end up being the goalie by default.
Some days, we jab at the school's water pipe, flooding the open drains. A week later, moss grows, fish and shrimp swim around—and even... leeches. The braver kids bring jars to catch the fish and raise them at home. I just stand there, wondering, "Is this what a secondary ecosystem looks like?"
I miss the nights at the net café too. Playing League of Legends until midnight, Tín would yell, "Man, the other team's such noobs!"—right before his mom storms into the café with a broom to drag him home.
And I miss those team math study sessions. We gather in our old classroom, the blackboard packed full of equations: functions, 3D geometry, complex numbers—each of us tackling a different set of problems, then teaming up to solve problems from Hanoi-Amsterdam High School, or the gifted schools of Hanoi and Nghệ An... Brain-meltingly hard. But back then, I just feel... warm inside.
Nothing special to adults. Nothing grand.
But to me, that is life—ordinary, close, and precious.
Something that now... feels like a luxury.
I'm walking down the main road of East Tarif—a neighborhood known for being peaceful, clean, and sleepy—when I bump into Hải.
"Hey! Minh!"—his voice comes before my brain even registers who he is.
I turn around. It's still Hải, my old Chemistry-Physics buddy, a guy full of antics, always looking like his brain's about to explode from some chemical reaction. His face is still the same as when we were on the national team: grinning wide, his chin jutting out like a vector arrow shooting toward an uncertain future.
"What are you up to these days?" I ask after a few greetings, our laughter echoing through the street like the air here is free of slave dust and magical residue.
Hải laughs and scratches his head, "Uh... oh crap, I forgot." And just like that, he turns around and bolts like an electron getting excited to a higher energy state.
I'm left standing there, brain still buffering, until fifteen minutes later, he jogs back, panting, hands on his hips.
"Uh... I'm out looking for herbs. For making medicine. It's crazy hard to make money these days."
"What about adventurer work?" I ask.
"Restricted," Hải grimaces. "The government's posted a bunch of notices: 'Monster breeding season. No hunting allowed to protect the ecosystem.'"
"This fantasy world's biology logic is more complicated than an International Ecology Olympiad question…" I mutter.
"Yeah, and that's not even it. I've been sweeping up all the easy quests near the guild. Made all the newbies so mad their balls probably exploded. Now I'm banned from taking jobs within 5km. They call me the 'Quest Vacuum.'"
I almost choke laughing.
"So now I have to go into the forest, pick some herbs, brew a few potions... sell to merchants. Trade for food. A few days ago, I even had to mix up some acid to... chase off a succubus."
We both burst out laughing.
Just when the atmosphere is as light as a sine curve, Hải suddenly switches tone:
"Oh yeah, Joon Soo's calling the team together."
I freeze. "Team? What team?"
"What else? The Strays."
My eyes widen. This is the first time I hear anyone talk about gathering the team in one place. Normally, each of us is scattered like magnetic poles pushing each other away.
"Where? Where are we meeting?" I ask, my voice shooting up like a free oscillation frequency.
"Cherry Blossom Forest."
I blank out.
"What?"
"Cherry Blossom Forest," Hải repeats, like it's as normal as buying bread at the market.
"This place is all desert, wheat fields, and dry forests. How the hell is there a cherry blossom forest?" I ask, my eye twitching like a fluctuating electric field.
"Shinji planted it," Hải says.
I'm stunned. "That Japanese guy? The one who wears that 'Demon Slayer' style outfit but in green?"
"Yeah. Fire element, forest-growing maniac, ultra Japanese."
I think it over...
Well... it's Shinji. Makes no sense and yet, somehow, makes perfect sense in this open-ended-logic world. I don't even know which natural law to trust anymore.
"Come on, let's hurry! First full assembly ever!" Hải yells, then bolts off again.
I glance down at myself. Regular clothes, no weapon. Look at Hải—same deal.
"No gear?" I ask.
"Whatever."
I nod. Whatever.
After all, it's the first time The Strays are fully summoned.
Maybe something big is about to happen—or maybe we're just meeting up to... play cards.
Either way, my heart's pounding like I'm about to solve a national math exam problem—and buzzing with excitement, like the first time I turn on my PC after a week-long blackout to finally play League of Legends.
Hải and I are sprinting through a temperate forest, our feet catching on all kinds of roots, dry leaves crunching under our heels like they're protesting us ruining their afternoon nap. This forest isn't beautiful in that fairy-tale kind of way either — it's more like... dark, messy undergrowth, with almost-bare branches looking like derivatives that keep getting differentiated until nothing's left.
I leap over a tree stump and—bam!—trip over something, flying forward like an object that just lost all momentum, and land anything but gracefully.
"Holy sh—"
"Hey, Minh! You good?" Hải rushes over and hauls me up. I'm dusting off my shirt, about to curse out loud, when my eyes lift... and I freeze.
Across a small ditch—right where I faceplanted—is a completely different scene. It's like this little trench is... the border between two worlds.
On the left, there's the gloomy temperate forest, all grayish-blue, draining every ounce of energy out of you.
On the right—it's a cherry blossom forest.
Cherry trees are bursting with pink flowers, petals drifting through the air like slow-motion confetti in some cheesy Japanese music video. The sunlight sparkles so much it makes me wonder if there's a 3D shader effect going on here.
"Who the hell dug this trench and made it the world border? It's like they just turned this place into a data partition or something..." I mutter, hopping over.
Hải glances around, clicking his tongue: "No idea where the exact path is. Shinji's so stereotypically Japanese. Looks pretty, but not a single GPS marker in sight."
We stumble around the forest. I almost step on a glowing mushroom. No clue if eating it would boost my attack damage or just nerf my IQ.
After a while of dragging our exhausted selves forward, we run into... someone sitting on a rock sketching something.
Wearing leather armor, bandages wrapped around the arms, a dagger strapped to the back, one eye covered with a black cloth, and hair spiked up like he just stuck a fork in a socket.
I recognize him instantly.
"Kỳ?"
"Huh? Minh? Hải?" — his voice is the same as ever, rough and crackly like a busted public loudspeaker.
I yank him up, and the three of us high-five before immediately diving back into humanity's most important topic: League of Legends.
"Dude, I swear, the new female champs' skins are insane. That Spirit Blossom Ahri skin? Straight-up Canadian ghost magic."
"No way! Seraphine's the real MVP. Beautiful voice, can flex between support and mid, tons of skins, easy item builds."
"But have you noticed? Everyone around here kinda looks like Ahri—hair floating around, and they talk like Tumblr quote bots."
We shoot the breeze for a solid 20 minutes, laughing like maniacs, even though deep down... we all know we haven't forgotten why we ended up lost in this world. But screw it — at least we're still laughing.
After that brilliant League meta analysis, the three of us go back to stumbling around aimlessly.
Still no clue where this "group call" meeting spot is supposed to be. Shinji didn't leave a sign, a map, not even a vague trail. It's like he wants this meetup to be some kind of terrain IQ test.
Then—BOOM!
The whole forest shakes like a boss monster just slammed into the ground.
The wind flips, cherry petals scatter everywhere, dust clouds swallow our vision.
"Which direction?!" Hải yells.
I scramble up, pulling out the manual mana tracker Veritas built for me: "Southwest! About... thirty kilometers!"
"What the hell???"
"To be exact... 30.2 km."
Kỳ gets up, slinging his dagger over his shoulder, grinning wide: "Then what are we waiting for? Let's haul ass!"
Hải puffs out his cheeks: "Tch. Typical Shinji, turning everything into open-world meta crap... Whatever, let's go."
The three of us—no real armor, no solid plan, no clue what we're even running into—still sprint like it's the only real thing left in this chaotic world.
The first time The Strays are summoned.
And apparently, the party kicks off with an explosion.