A single breath of air in the Serenitea Pot made the throat sting with heat. The grayish-white soil of the experimental plot cracked open in ferocious fissures, greedily swallowing the last drops of moisture. The Chisui Double-Resistant No. 3 corn seedlings that had stood tall and proud just days ago now drooped listlessly, their leaf edges withered, yellow, and curled, their vitality ebbing visibly before the eyes.
Limeng crouched on the edge of the field like a frozen statue. His fingertips pinched a dry lump of earth, and with the slightest pressure, it crumbled into powder between his pads, sifting down in a rustle. A shortage of water. The prelude to a system crash. An engineer's instinct locked his brow into a tight frown, subconsciously running through troubleshooting protocols in his mind—though here there were no circuit boards, only the splitting earth.
The background noise was a web woven from whispers of despair. Before the public water collection point, the winding dragon-like queue stretched endlessly. Murky, muddy water dripped sluggishly from an old pipe opening, splashing into the broken bowls held by refugees and kicking up tiny specks of dust. Every single drop was as precious as oil. The cracked lips of the people moved silently, their eyes numb and hollow. Ganyu hurried past carrying a thick ledger, her usually gentle horns seeming exceptionally heavy in this moment, a shroud of dark worry across her face. Every step she took trod on the razor's edge of the clean-water hub's production capacity limit—a limit that acted like an invisible noose tightening around everyone's throats, growing steadily constrictive.
"Make way! Everyone make way!" A sharp voice, like sandpaper scraping across sheet metal, pierced the sluggish despair.
The crowd was shoved roughly aside by two bulky bodyguards with fierce, fleshy faces. A well-dressed Sumeru merchant with a slightly protruding belly strolled out, wearing a look of condescending arrogance. Holding something between his thumb and forefinger, he raised it high like a rare and priceless treasure—a standard water purification filter core. The crystal mineral fragments at its core were wrapped in a thin, almost transparent hydro-spirit condensate gel, emitting a faint, ghostly blue glow that symbolized hope.
"Take a good look, everyone!" The merchant drew out his tone, his gaze sliding like an oil-coated brush across one parched, despairing face after another. "One standard filter core, traded for ten catties of Chisui corn! Fair trade guaranteed, no deception!"
The crowd exploded instantly.
"Ten catties?! That's the food that keeps us alive!"
"Black-hearted thief! You're taking advantage of our crisis!"
"Millelith! Do something about him! Is there no law left?"
Waves of angry shouting rose and fell, hoarse with the sound of the dying. The Millelith soldiers maintaining order tightened their grips on their long spears, their knuckles turning white, their expressions grim, and their lips pressed into straight lines. They could suppress a disturbance, but they were powerless to sever this naked greed. The smile on the merchant's face deepened, carrying the smugness of charity as if he were looking at a flock of lambs waiting for the slaughter.
Limeng stood up. His movement was not fast, but it carried an unquestionable, piercing momentum. He pushed past the people blocking his path and walked straight up to the merchant. There was little expression on his face, save for the focus and calm of an engineer facing a stubborn bug. He held out his hand. His voice was not loud, but it cut clearly through the din like cold metal: "Let me see the filter."
The merchant raised an eyebrow, seemingly surprised by his composure. Hesitating for a moment—perhaps figuring the man posed no threat—he handed over the filter with a hint of contempt. "What? Do agricultural experts lack these things too?"
The filter felt cool in his hand, carrying the characteristic hard texture of crystal minerals. Limeng's gaze was as sharp as a blade, instantly entering "disassembly and analysis" mode. The structure of the crystal minerals, the way the gel wrapped around them, the nodes of energy flow... His fingertips unconsciously stroked the rough casing of the filter, feeling the minute bumps and ridges. At that exact instant, a familiar, mild wave of dizziness violently struck him.
The fragments of modern knowledge in his mind suddenly churned and collided! No longer vague concepts, they formed a clear picture: honeycomb-like black particles riddled with micro-pores. A massive, labyrinth-like adsorption surface area. In the laboratory, turbid, blackened industrial wastewater flowing through that unassuming layer of black particles, instantly turning clear and transparent...
Activated carbon!
The term cracked open the fog before him like lightning tearing through chaos!
"Activated carbon..." he muttered to himself, as if confirming a long-awaited answer. His gaze abruptly shifted away from the filter, shooting toward the edge of the field like a precisely targeted probe—there, piled like mountains, were the golden corn cobs. Basking in the sunlight, they gave off a dry scent; they were the waste left over after the Chisui harvest that nobody wanted, deemed too smoky even to use as firewood! "Corn cobs... can be used to make activated carbon!"
The moment the thought arose, his body sprang into action. An engineer's decisiveness was on full display. Without a second thought, Limeng grasped the filter core and turned on his heel, moving with clean, crisp efficiency while completely ignoring the startled and angry shouts behind him: "Hey! What are you doing?! My filter! Are you a robber?!"
In a few strides, he rushed up to the nearest on-duty Millelith soldier, shoved the filter into the man's hands, and spoke at the speed of a rapid-fire crossbow: "Register it into storage! Emergency use! Don't give it to that profiteer!" Before the words had even faded, he was already sprinting like an arrow released from a bow toward the direction of the abandoned Millelith barracks. Piled high within those walls were mountains of corn cobs—his only raw material of hope at this moment.
The corner of the abandoned barracks instantly transformed into a temporary laboratory crackling with primitive human industry. The mountain of golden corn cobs was brutally smashed and crushed by Limeng using stones he found lying around. Working with nimble hands and feet, he used clay to fashion a crooked, rudimentary crucible, packing the crushed corn cobs thickly inside and pressing them down firmly. Sweeping his gaze around, he picked up an abandoned Millelith shield with a rolled, battle-scarred edge—this would be his blower fan.
Oxygen-deprived combustion. Controlling the temperature was the key. They couldn't be burned to ash; the pore structure had to be preserved! He recited the key points to himself, took a deep breath, and swung the heavy shield with all his might.
Whoosh! Whoosh!
Thick black smoke carrying a pungent, charred odor surged into the air like a ferocious black dragon, stinging his eyes with tears and sending him into a fit of coughing. Sweat quickly seeped out, mixing with the falling charcoal dust to streak his face with disheveled black trails. He paid it no mind, keeping his gaze locked on the faint red glow visible inside the crucible, as focused as someone debugging a precision circuit board. Every swing of the makeshift fan used every ounce of his strength, and though the muscles in his arms ached fiercely, he ignored it entirely.
A few passing Sumeru scholars, attracted by the bizarre sight and thick smoke, stopped at a distance and pointed.
"What is he doing? Burning those useless cornstalks?"
"Good heavens, this method... it's so barbaric! He acts practically like an uncivilized Hilichurl!"
"This smoke... smells a bit strange..." A gray-haired older scholar wearing thick glasses frowned, sniffing hard. A flicker of bewildered uncertainty flashed in his cloudy, aged eyes as he muttered, "There's a hint of... special charcoal in the burning smell? Why does this... why does this somewhat resemble the scattered records of the 'Black Stone' ancient purification method from that tattered manuscript, *Sumeru Ancient Water Purification Studies*?" He pushed up his glasses, his steps drifting forward involuntarily as his murky eyes revealed a researcher's intense focus.
The open space beside the experimental plot. The crowd had long since been drawn in by the odd, dense smoke and the commotion, packing the area three deep and leaving the air as taut as a drawn bowstring. Anxiety, suspicion, and a fragile spark of forcibly ignited hope intertwined across every weary face. The Sumeru merchant was squeezed out to the periphery, his complexion as ashen as a rusted copper coin. Clenching his remaining few filter cores, his knuckles popped, and his eyes—as sinister as poisoned needles—were nailed straight onto Limeng, who was busy at work in the center.
Limeng paid no heed to the surrounding clamor. Working deftly with a few rotting wooden boards and several rusted, mismatched waste metal pipes, he cobbled together a crude, funnel-shaped apparatus. The bottom layer was lined with sand and stones washed clean from a nearby ditch to roughly filter out large impurities. Then, he carefully scooped out the still-warm, pitch-black, roughly textured, irregularly shaped corn cob activated carbon particles from the crucible—the spoils of his battle amidst the thick smoke and sweat—and spread them evenly across the middle layer. Finally, he capped it with another layer of washed sand and stones for protection.