When absolute darkness descended across the wilderness, only two sources of radiance endured in the entire block world: the silver moon high above, and the sprawling silhouette of Redstone Tech City.
Beyond the walls, the distant forest blurred into an unbroken ribbon of shadow, shifting like a living tide that rolled steadily toward the perimeter.
Ryen cast a knowing glance toward Ningguang. Meeting his eyes, she stepped forward onto the battlements, her voice ringing out crisp and clear across the ramparts.
"Ignite the beacons!"
In the very next heartbeat, dense pillars of pure light erupted from the heart of Redstone Tech City, piercing straight into the upper atmosphere.
Blinding white radiance cascaded across the plains, turning midnight into stark, unforgiving day.
Before anyone on the walls could marvel at the magnificent spectacle of countless beacons firing in unison, the illuminated landscape tore the breath from their throats.
Even having mentally prepared for an apocalyptic siege, the living reality before them was suffocating.
Across the rolling hills and open plains, the earth had vanished.
There was only a sea of rotting flesh stretching to the edge of the horizon, where endless pairs of crimson eyes gleamed in the night like a dense, malevolent constellation.
A chorus of raspy, guttural shrieks rolled toward the walls in overlapping waves.
Seen from high above, Redstone Tech City stood like a solitary stone island encircled by an ocean of darkness, waiting for the crashing surge to swallow it whole.
"This... isn't this number a bit too insane?! This is only the first day!"
Venti lost every trace of his usual carefree charm, his knuckles whitening as his grip tightened around his weapon.
Judging by eye alone, the hostiles pressing against their northern sector numbered easily in the tens of thousands; how many tens of thousands, Venti did not dare calculate.
It was certainly no modest gathering of one or two thousand.
"East, South, West, report your readings," Zhongli commanded calmly, taking control of the tactical relay as his deep voice resonated through the communications grid.
"Eastern sector: estimate exceeds twenty thousand," Ayato reported.
"Western perimeter: confirmed count exceeds ten thousand," Tartaglia answered.
"Southern front... preliminary estimate sits near forty thousand!"
Listening to the reports, Zhongli rapidly calculated the density in his mind.
"A conservative total for tonight's assault sits well above a hundred thousand," Zhongli murmured, pressing his fingers lightly against his brow.
A hundred thousand undead was not an immediate catastrophe in itself.
They lacked mutation, and behind heavily reinforced battlements, modern firepower could thin them down; at worst, the morning sun would reduce them to cinders.
Yet what of the final seven days, when identical or even greater numbers would march each night?
When that hour came, simple terms like difficult would lose all meaning.
A single lapse in concentration would allow the horde to overwhelm the ramparts, leaving not a blade of grass standing within the city.
"Are you confident?" Ryen asked softly, noticing the quiet tension in Zhongli's eyes.
"For the early days, yes. As for that final mutated phase..."
Zhongli paused, slowly shaking his head.
"We can only leave that to fortune."
Ryen nodded, offering a gesture of steady trust.
"I leave the field to you."
Zhongli said no more, turning his focus back toward the tactical array as he issued a sequence of measured commands.
"When the horde breaches the first defensive marker, redstone artillery shall establish an active saturation zone. Once they cross the second line, both redstone cannons and RPG fire are authorized at will."
"Should they cross the third perimeter, machine gun emplacements will open continuous sweeping fire."
"If any cluster reaches the base of the wall, deploy Splash Potions of Healing immediately! Aside from those parameters, conserve your ordnance."
"Launch no counterattacks. We hold until the dawn!"
The moment his orders settled, deafening explosions detonated along the outer perimeter.
The opening week of the cataclysm was largely manageable; the zombies were merely numerous. With all gates blocked by solid obsidian, mindless corpses incapable of using tools could never breach the thresholds.
Holding until dawn meant the sun would do the heavy lifting, incinerating whatever survived.
These initial nights served primarily as a drill to adapt the allied troops to the pace of siege warfare.
The real war would begin when the first Blood Moon rose on the seventh night, introducing biological mutations into the horde.
The immediate worry was whether every night leading up to that point would match this opening assault in scale.
If so, attrition would become their greatest enemy.
Ants could devour an elephant through sheer weight, let alone an endless host of rotting corpses.
Cloud Retainer and the adepti were already directing the Millelith batteries, saturating the densest clusters beyond the ditches.
Ryen watched the explosions light up the plain before murmuring, "Tonight presents no true danger. We simply need to hold our ground."
Zhongli nodded, though a trace of concern lingered in his golden eyes.
"The scale of this first wave far exceeds my projections. I anticipated a few tens of thousands per night at most."
"If every night demands this volume of fire, our logistical reserves will not last!"
"Our ammunition stockpiles, in particular..."
"Our current stores cannot sustain forty-nine days of continuous bombardment. If our magazines run dry and our soldiers are dragged into prolonged close-quarters combat, casualties will be unavoidable."
Zhongli turned his gaze toward Ningguang, who oversaw the coalition's logistical supply chains.
Her brow furrowed slightly as she calculated their assets.
"Our regional storehouses across the Main Continent still hold vast stockpiles. If we mobilize transport squads to consolidate those goods here and ration our fire, we should manage."
"Tomorrow morning, I will dispatch couriers to transfer those caches. Furthermore, we retain a substantial quantity of Lucky Blocks."
"We originally intended to save them for post-war development, but under the circumstances..."
"We can unseal a portion and have Ganyu open them to replenish our raw munitions."
Zhongli considered the proposal before offering a firm nod.
"Very well. Let us proceed with that plan."
He turned his attention back to the plains below.
Dense as their artillery barrages were, against a swarm of this magnitude, only non-stop carpet bombing could truly halt their advance.
Within minutes, several forward clusters had pushed through the smoke, reaching the foot of the outer wall.
Zhongli studied their behavior intently. The zombies merely crowded together on the bare earth, lacking the wit to claw at the blocks, staring upward with vacant, groaning jaws.
A quiet breath of relief escaped his chest.
"All sectors, cease fire temporarily. Observe the enemy's interaction with our ramparts."
The thunder of gunpowder and redstone died down, leaving only the chaotic howling of the horde vibrating through the stone.
Zhongli monitored the status reports from each battle group, confirming that the undead were entirely incapable of mining through blocks.
Their only threat lay in their sheer physical volume; as more piled up against the foundation, corpses began climbing atop one another in crude, shifting pyramids to reach the parapet.
After a moment of deliberation, Zhongli spoke into the relay.
"Abandon broad saturation fire. Transition to rotating observation watches. There is no need to actively spend ammunition on every target; simply ensure they do not scale the lip of the wall."
"Let them gather. When the morning sun climbs over the mountains, the light will burn them away."
Nods of agreement rippled along the battlements.
Since the creatures possessed no tools to dismantle their fortifications, expending high-grade ordnance was a waste of resources.
Waiting for dawn was far more sensible.
Gunpowder and modern cartridges did not grow on trees.
When the colossal horde had first emerged from the forest, it had sparked a momentary tremor of dread; such numbers were unprecedented in living memory.
Yet once the defenders confirmed that these creatures were no different from standard nighttime mobs and carried zero mutations, the initial panic melted away.
Numbers meant very little if they could not breach the perimeter.
When morning came, the troops could simply descend with pickaxes and gather the dropped loot at their leisure.
Seeing that the first night had settled into a predictable, manageable rhythm, the leaders felt no need to linger on the windy parapets.
After observing the lines for a while longer, Ryen turned to lead Ningguang and the inner circle back toward the City Lord Manor.
He offered a casual parting wave.
"Manage the night as you see fit; I will not micromanage the watch. The horde will not mutate during the first seven days, so this week represents our quietest window."
"Use this time to refine your defensive traps."
Mid-stride, Ryen paused, turning back as though struck by an afterthought.
"One detail to keep in mind: no matter how these creatures mutate later on, they will always retain their fundamental zombie nature."
"Their attraction to living intellect is overwhelming."
"Sometimes, channeling the water is far wiser than building a higher dam."
Leaving that thought hanging in the cool night air, Ryen led his companions down the stone steps.
A tactical intellect of Zhongli's caliber required no heavy-handed instruction; a single spark was enough to illuminate the path.
Sure enough, the moment Ryen vanished down the corridor, Zhongli's amber eyes lit up with sudden clarity.
Xiao looked at him in mild confusion.
"Lord Morax, what was Mr. Ryen implying?"
"Channeling the water rather than damming the flood," Zhongli repeated with a faint, appreciative smile.
Xiao remained perplexed.
Looking out over the milling sea of corpses beneath the battlements, Zhongli turned back, speaking in a low, measured cadence.
"When managing a catastrophic flood, relying purely on towering dams often yields poor results. How do you view it, Xiao: is it better to block every drop, or to carve relief channels?"
Xiao considered the metaphor, murmuring thoughtfully, "If one merely builds walls, the water builds pressure until every levee collapses simultaneously. Providing controlled channels relieves the pressure on critical sectors."
Zhongli held his gaze quietly until understanding flashed across the yaksha's face.
"Lord Morax... Mr. Ryen wants us to open deliberate gaps in the fortifications of Redstone Tech City?"
Zhongli gave a slow, deliberate nod.
"The zombies are vast in number, yet currently unable to dig through stone."
"If future mutations grant them the power to tear through blocks, holding an unbroken perimeter will stretch our garrison beyond their limits, inviting breaches across every front."
"What happens, then, if we intentionally open specific breach points?"
"Drawn by the scent of living defenders, the horde will naturally funnel into those clear pathways, drastically reducing damage to the surrounding obsidian walls."
"And we can design those funnel zones much like automated mob-grinding towers."
"We can excavate drop pits beneath the openings, allowing thousands of zombies to plummet into contained kill zones. That will give us a safe, systematic method to thin the horde while shielding our main ramparts from total collapse."
A wave of revelation swept through the commanders on the battlements. Xiao bowed respectfully, his voice filled with admiration.
"Your wisdom is profound, my Lord. When morning arrives, I will direct the engineering battalions to excavate drop channels along the perimeter."
Venti blinked, tilting his head with curious skepticism.
"If that is the case, old man... why not simply dig a massive trench around the entire outer wall, deep enough to smash them to pieces on impact?"
Before Zhongli could reply, Diluc cut in with a cool, sharp cadence.
"Do you have any grasp of Redstone Tech City's true geographic footprint? How many laborers and how many weeks would it take to encircle an entire metropolis in an execution trench?"
"Even utilizing Vein Miner to clear stone, completing such a project within thirty days would be impossible."
"Furthermore, these creatures will mutate. If they equip armor, a fall from that height will not kill them, leaving them free to tunnel directly beneath our foundations and emerge within the city streets."
"It would waste immense labor for negligible gain."
Venti pouted, crossing his arms with an aggrieved huff.
"And opening local funnels will smash every single zombie to dust? It carries the exact same flaw!"
Jean pressed two fingers against her temples, letting out a quiet, embarrassed sigh.
"Lord Barbatos... have you considered that we can station combat squads at the base of those funnels to execute weakened survivors?"
"Or that we can line the collection pits with lava to incinerate them automatically?"
Venti coughed awkwardly, clearing his throat as he tried to find a retort.
Beside him, Rosalyne rolled her eyes with undisguised contempt.
"If you dare suggest digging a city-wide trench and filling that with lava instead, I will formally question your mental faculties."
"We are already flooding the subterranean networks beneath Redstone Tech City, leaving our liquid reserves heavily depleted."
"Have you calculated how many tens of thousands of lava buckets would be required to encircle an entire urban horizon?"
"This is a capital metropolis, not a mountain villa."
Venti offered a meek, sheepish grin under the unified glares of the Mondstadt and Snezhnayan commanders. Acknowledging that he had spoken far too casually, he wisely sealed his lips and retreated into the background.