Under the night sky, Black Mountain City resembled a slumbering behemoth—and when the castle gate shattered with a thunderous crash, that giant finally awakened.
Stone fragments scattered, dust surged. The monsters roared as they swarmed through the breach. Twisted by black ore, their mutated forms bore jagged bodies and crimson eyes. Corrosive black mist curled around their claws and fangs, and every step they took sent tremors through the ground.
"Prepare for battle!" Leo shouted, stepping forward and raising his battered sword. The Void Ring on his hand pulsed with deep violet sigils as fire and wind elements surged like liquid from it, coating the broken blade.
Though fractured, the sword now gleamed like a fang of flame, radiating searing bloodlust.
He charged into the enemy ranks, swinging in a wide arc. A crescent-shaped flame carved through the air, cleaving three overzealous monsters in half. The wind element erupted afterward, stirring a hot vortex that hurled the severed bodies into the remains of the city wall.
"Don't fall behind!" Dan followed closely. His twin blades spun and flickered like silver lightning between his arms. Slashing through the swarm like a darting fish, he crossed his blades over a roaring monster, disemboweling it in a single move. Black blood sprayed across his calm, water-like face.
Meanwhile, he began chanting in the ancient tongue of the merfolk. The melody was eerie and cold, carrying a strange penetrating power.
"Aaaargh—!" Several monsters suddenly froze, their limbs locking in place, eyes turning murky blue. Then they began to tear into one another with frenzied violence.
"Wind of the Elves, swift as shadow." Vivella stood on a raised platform, drawing her bow with glowing green fingertips. Each arrow traced a graceful arc through the air, striking monsters with deadly precision. She chanted in Elvish, imbuing her teammates with speed-enhancing magic. Leo and Dan moved noticeably lighter.
"Thunder's Descent!" Luna raised her staff high. Magic circles formed around her, and blue-white lightning crackled at her fingertips. A massive bolt struck a hulking monster, blasting it—and several nearby creatures—into the air in a flash of searing light.
She nimbly retreated a few steps, eyes calm and focused. Though a mechanical automaton, her magical computation was flawless—each bolt hit its mark with pinpoint accuracy.
Yet the number of monsters did not diminish. On the contrary, they surged forward more wildly than before. As if driven by an invisible will, they ignored death, trampling over the corpses of their kin to push deeper into the castle.
"There's too many! We have to fall back!" Dan shouted as he severed a monster's front limb.
"Fall back to the main hall!" Vivella called out as she loosed another arrow. Her quiver was nearly empty.
"I'll hold the rear!" Leo gritted his teeth. The flame on his sword had turned a deep crimson, and the Void Ring's energy was rapidly depleting.
"You're not staying alone." Luna had already gathered energy beneath her feet. A "Lightning Shift" spell triggered, teleporting both herself and Leo backward to regroup with Vivella and Dan.
Fighting as they retreated, the four made their way down a long corridor, waves of monsters at their heels. Finally, they slipped behind a half-collapsed stone gate. Dan sealed the passage with rubble, granting them a moment to breathe.
"It's scorching in here…" Vivella frowned as she scanned the area. Her eyes suddenly lit up. "This is the Foundry! The old underground furnace used for refining magic ore!"
"You mean these machines might still work?" Luna's mechanical lenses shifted. A glint flashed in her eyes. "We might be able to reactivate the core…"
"You're thinking—?" Dan was taken aback.
"Lure the monsters in, then dump molten metal from the furnace on them," Vivella said firmly, her eyes sharp.
"I like the sound of that." Leo smirked, tightening his grip on the broken sword. "I'll handle the baiting."
"I'll go to the control room." Luna was already scanning the mechanical layout. "Reactivating the main energy system."
"Then I'll handle support and the arrow formation." Vivella quickly climbed onto a half-destroyed steel beam, bow at the ready from her elevated perch.
"I'll guard the rear with Leo." Dan drew his twin blades, his tone grave.
As Luna activated the control system, the entire Foundry rumbled to life. Gears slowly engaged, steam hissed, flames roared, and beneath the boilers, molten iron began to glow red. The once-silent mechanical world awakened again.
A piercing shriek broke their brief calm. The monsters had breached the gate once more, swarming into the Foundry—this time, in even greater numbers.
"Come on, then." Leo grinned, stepping forward. Fire and lightning from the Void Ring wrapped around his blade, which now exploded with bursts of radiant energy. Like a battle flag in a storm, he stood firm before the horde.
The first monster lunged, jaws open wide—only to be impaled by a blast of fire and lightning, howling in agony.
Dan moved like a blur along the edges of the horde, his twin blades slicing in harmony. Each strike accompanied by the low hum of merfolk song, gradually slowing the monsters down.
Vivella switched her arrow formation to "Armor-Piercing Barrage," loosing arrows in triads aimed at joints and bellies, crippling enemy movement.
But the furnace's heat had yet to reach melting point.
In the control room, Luna's hands flew across glowing circuits. "We need more power… I'll have to overheat it manually."
Luna suddenly turned and dashed toward the boiler heater, the mechanical core in her chest thudding violently as if it sensed the sacrifice she was about to make. The metal armor on her right arm slowly opened, and streams of shimmering golden mechanical fluid gathered in her palm, leaping like a living entity.
"Luna!" Vivella cried out, reaching for her, but she was a step too late.
Without hesitation, Luna splashed the golden fluid onto the heater. The potent magical energy contained within was instantly absorbed by the machinery, triggering a series of deafening booms. The energy bar of the heater filled up in an instant, and the previously slow-melting molten iron began to boil. It was as if the furnace had ignited a second heart—its temperature surged, turning the air in the smelting plant scorching hot.
"Come on… come on…" Luna whispered, her legs weakening as she collapsed to the ground. Her mechanical body had grown sluggish and frail from the loss of a portion of her core fluid.
But the monsters were already closing in. Their breath carried a searing stench of rot. One particularly ferocious beast had silently crept up behind Luna, its razor-sharp claws mere inches from slashing into her back.
"Luna, watch out!" Vivella's staff lit up, and a green barrier sprang into place, blocking the monster's strike. The shield trembled violently but held firm.
At the same time, Leo and Dan charged in from either side.
Leo wielded his broken sword, the runes on the Void Ring glowing a deep blue. Ice magic surged through the ring into the blade, and the damaged sword was instantly encased in frost, forming a temporary "Ice Blade." He leaped into the fray, his movements swift and feline, cleaving left and right. The nearby monsters were shattered into icy shards.
Dan's twin blades gleamed coldly as he chanted a song of the merfolk. The strange melody reverberated through the air, slowing the movements of nearby monsters. He seized the opportunity and dove into their midst, his blades slicing like a whirlwind, swiftly cutting down several beasts in his path.
"Get her out of here!" Dan shouted.
Leo rushed to Luna and scooped her up. Luna murmured, "The boiler's almost ready… we have to move fast."
The four regrouped. By now, more and more monsters had flooded in, nearly filling the entire smelting plant. They roared, clawing their way forward.
The boiler finally let out a click, followed by a long, shrill whistle. A wave of heat burst forth, signaling the molten iron had fully melted.
"Now!" Leo commanded.
They exchanged a glance and nodded in unison. No words were needed—only instinct and trust.
The four sprinted toward the diversion channel beside the boiler, the designated path for pouring molten metal. Just as they left the control console, the boiler tilted with a thunderous roar. Scalding iron poured out like a volcanic eruption, crashing down on the pursuing monsters.
Molten metal splashed in all directions, instantly covering a corner of the plant. Sharp, agonizing shrieks rang out as the monsters caught in the flow were scorched to the bone, smoke rising from their charred remains. The air filled with a nauseating stench of burnt flesh.
"Run!" Dan shouted.
The molten metal surged across the floor, moving as fast as a sprinting human. The four raced forward at full speed, the searing iron chasing them like a wild beast. Luna leaned on Leo as they ran. Vivella fired ice arrows behind them, slowing the metal's advance. Dan cast barrier after barrier to block its path.
Just when they thought they had escaped, they came upon a dead end—solid metal walls with no exit.
"Damn it, a dead end!" Dan growled.
They skidded to a halt and turned. The monsters had already flanked them from both sides. The few beasts that had escaped the molten metal were now even more frenzied, drooling acidic saliva that hissed on contact with the ground. Sparks danced on their claws and fangs, their minds consumed by bloodlust.
Luna's face turned pale. "We're not getting out of this…"
The monsters surged forward, their deafening roars shaking the chamber. Just as their fangs were about to sink in, a golden light suddenly burst from Dan's chest. He looked down—it was the ring given to him by the Elven King, Faelar.
The golden light shot forth, instantly shattering a few monsters ahead into fragments before rising into the air and hovering in place.
A spinning portal materialized in the air, radiating with brilliance. The next moment, a tall elven man stepped through—his silver cloak flowing, long hair draping over his shoulders, his face handsome and severe.
"It's… Faelar!" Vivella gasped, awe in her eyes.
"How did you…" Dan began.
Faelar smiled slightly, as if expecting this. "That ring is enchanted to alert me the moment you're in a life-threatening situation. It seems I arrived just in time."
As his feet touched the ground, the temperature of the entire space seemed to drop. The monsters froze under his pressure, a trace of fear in their eyes.
"Stand down," Faelar said softly. His voice was calm and cold as falling snow.
The monsters instinctively backed away, but more poured in from behind, creating a tide-like encirclement.
Faelar raised his right hand, silver magic runes glowing at his fingertips. With a casual wave, a blade of light sliced through a dozen monsters, cutting them in two before they could react. Their corpses smoldered as they hit the ground.
"Damn…" Dan inhaled sharply. "This is the first time I've seen him fight seriously."
Faelar's face remained icy, his movements swift and precise. With every gesture, swathes of monsters fell. But his brow gradually furrowed as he realized the creatures were not retreating. On the contrary, they were growing more berserk.
Just then, a strange humming rose from deep underground—low and steady, like some slumbering being was awakening.
The monsters suddenly ceased their howls. They raised their heads, blood-red pupils gleaming. As if possessed by a collective will, they roared in unison and charged again, heedless of pain or death.
"They're being controlled!" Luna cried.
"There's something… down there," Vivella murmured.
Faelar's eyes narrowed. "Some kind of awakened central brain… these monsters are merely puppets."
As the monsters swarmed again, Faelar's magic intensified. The four companions readied themselves once more, but they knew they couldn't hold off this madness forever.
Then, the underground hum surged in frequency.
The next second, the monsters abruptly froze, their eyes flickering with confusion. Then, without warning, they turned and rushed toward the massive mining pit at the side of the smelting plant.
"They're… retreating?" Leo frowned.
The four, along with Faelar, stood motionless as hundreds of monsters leapt into the pit without hesitation, drawn by some overwhelming force.
Faelar slowly withdrew his magic, gazing down into the pit, his frown deepening.
"It seems the real threat… has only just begun," he said.
Below the pit, endless darkness loomed—an abyss that devoured all light.