Mithril Cave – 500 Meters Deep (Layer 1: The Old Mines). Midday (Though Eternal Darkness Reigns Below).
The world beneath the surface had its own laws. Here, time seemed to stand still. There was no sunrise or sunset, only an eternal darkness that devoured every kind of light.
The rhythmic thud of twenty-five pairs of boots echoed through the vast stone corridor. CLACK... CLACK... CLACK... The sound of their iron boots bounced off the damp walls, creating a monotonous and hypnotic rhythm.
The crystal headlamps on their helmets provided the only illumination, sweeping across cave walls that shimmered with veins of iron ore and raw quartz crystals. Yet, the light offered no sense of security. Instead, the shadows cast in the corners of the cave seemed to move on their own, watching them.
At this depth, the air felt cold, damp, and heavy. The scent of wet earth mingled with a pungent aroma of ancient fungus.
Sir Riven led at the very front. His massive shield was raised halfway, covering his chest. He was on full alert. His eyes swept through every rock crevice and dark turn. His hand gripped the handle of the Chain-Axe so tightly that his leather gloves creaked.
Behind him, Captain Garrick and his men aimed their spears in all directions, their fingers ready on the triggers of their Muskets (which they carried as backup).
However, after an hour of trekking down the spiral corridor, Riven felt something was wrong.
Very wrong.
"It's too quiet," Riven whispered. His voice shattered the silence, causing several soldiers behind him to flinch in surprise.
"What do you mean, Brother?" asked Sir Rianor, who was walking in the center of the formation, his eyes never leaving his compass and map.
"This cave..." Riven stopped in his tracks, staring into the darkness ahead. "A cave this deep should be noisy. The sound of dripping water, cave rats, bats, or at least the wind."
Riven pointed around him.
"But this? It's empty. Total silence. I can't even hear my own breath if I stay still."
Lady Rumina approached the cave wall. She rubbed the smooth, wet stone surface with her glove.
"Brother Riven is right. Even moss doesn't grow here. The walls are clean, as if they've just been sanded. There's no insects, no organic life."
"Elara's sonar is also negative," Elara added, tapping her sensor staff, its tip flickering weakly. "No signs of life within a five-hundred-meter radius. It's like we're walking inside a giant tomb."
They continued their journey with doubled vigilance. The silence pressed against their minds bit by bit. Every scrape of armor sounded like an explosion in their ears.
Thirty minutes later.
"Stop," Rianor ordered suddenly. His voice was sharp.
"What is it? An enemy?" Riven immediately took a defensive stance.
Rianor held up the compass in his hand. The directional needle was spinning wildly, 360 degrees without stopping, like a top that had lost control.
"The magnetic field is chaotic. We've just crossed the normal threshold. We're entering an anomaly zone."
"Look ahead," Lady Rhea whispered, her sharp eyes piercing the darkness better than anyone else. "Twelve o'clock. There's light."
Riven aimed his helmet lamp in the direction Rhea pointed.
In the middle of the vast cavern, there was a flat, open area.
And there, a Campsite stood.
There were remnants of canvas tents, torn and decayed by age. Ancient mining tools—rusted pickaxes, shattered wooden wagons—lay scattered on the ground. And in the center, there were the remains of a campfire that had turned to cold ash decades ago.
But it wasn't the tents that made their blood run cold.
It was the inhabitants.
Twelve human skeletons, still wearing the remnants of ancient mining uniforms with the crest of the old Aethelgard Kingdom.
They sat in a circle around the remains of the campfire.
Their positions were... relaxed.
Utterly relaxed.
One skeleton sat leaning against the shoulder of another, as if sleeping.
One held a metal cup in its bony hand.
Another held a deck of playing cards, their colors long faded.
There were no signs of a struggle.
No broken bones.
No drawn weapons.
No defensive positions.
They had simply died while they were resting.
"By the Gods..." Garrick whispered in horror, lowering his spear. "They died... while taking a break?"
Elara dared to step closer. She examined one of the skeletons with her medical magic. She touched the jawbone that was wide open, as if the person had been laughing when they died.
"No toxic gas residue in their bones," Elara analyzed. "Their gas masks are still hanging around their necks, meaning they felt the air was safe at the time."
"Then what killed them?" Riven asked, his hair standing on end. "A mass heart attack?"
Rianor knelt beside a skeleton that seemed to be the squad leader (based on the remnant of a foreman's hat on its head). He reached into the fragile shirt pocket and found a small, thick leather-bound Logbook.
The paper was yellow and brittle, but the magical ink used made the final entry still faintly legible.
Rianor read it aloud, his voice echoing in the cave's silence:
"Day 40. We found the door. But we are tired. The sound... ah, the sound is so beautiful. Like a mother's lullaby. We don't want to go home. Why return to a cold world when it's so warm and peaceful here? The hunger is gone. The pain in my legs is gone. We only want to sit here... listen... and sleep."
Rianor closed the book slowly.
"Sleep?" Riven asked. "You mean they just fell asleep and died?"
"They starved to death," Rianor concluded coldly. "They sat here, hypnotized by that 'sound,' until they forgot to eat, forgot to drink, forgot to move. They died slowly in a state of hallucinatory euphoria."
TING.
Suddenly, a faint chiming sound was heard.
It was very soft. Like a small silver bell being shaken by the wind.
Or like the hum of a woman from a distance.
Everyone went silent. They looked at each other.
"Do you hear that?" Rumina asked, her eyes widening.
"Hear what?" Riven asked, confused. He heard nothing but the sound of his own breathing.
"The bells," Rumina said. "No... it's a song. It's so beautiful."
"I don't hear anything, Rumi," Riven said firmly, beginning to panic. "Elara? Do you hear it?"
Elara shook her head, her face pale. "No. But my mana sensors are vibrating like crazy. There's a strange energy wave."
"I hear it..."
The voice came from the back of the line. It was a soldier named Borch.
The large, bearded man lowered his spear. His once-vigilant eyes were now vacant, his pupils dilated. His lips curled into a strange, out-of-place smile.
"The voice... it sounds like my wife..." Borch muttered. "My wife who died five years ago..."
Borch began to step out of line. He walked toward a dark corridor on the left side of the cave—a corridor that didn't exist on Rianor's map.
"Darling? Are you there? Are you calling for me?"
"Borch! Hey! Get back in line!" Garrick shouted.
Borch didn't hear him. He continued walking like a living corpse, drawn by something in the darkness. "Wait for me, Darling... I'm coming..."
"DON'T LISTEN!"
Elara screamed. She slammed her magic staff against the stone ground.
BOOM!
A Mana Shockwave exploded, hitting Borch's back. Not to harm, but to wake him.
Borch gasped in shock, falling onto his rear. His eyes blinked rapidly in confusion. "Huh?! What?! Where... where am I?"
"You almost walked off a cliff, you idiot!" Garrick snapped, pulling his subordinate up.
"Psychic Attack," Elara said, her breath heavy. "Something is emitting low-frequency sound waves that can't be heard by normal ears, but they go straight into the brain. It triggers happy memories, numbing one's sanity."
Rianor understood immediately. "The guardian of Layer 1 isn't a physical monster. It's an Underground Siren."
"EVERYONE! EQUIP YOUR REBREATHER MASKS!" Rianor shouted.
"Not for breathing! Set them to Sound Isolation Mode! Rumina, turn on the White Noise Generators in your helmets! Don't let there be even a second of silence!"
Everyone panicked as they donned their masks.
CLICK. HISS.
The sound of static (white noise) filled their ears, blocking out the mysterious song. Their world became noisy with static, but at least they were safe.
However, Riven... whose battle instincts were the sharpest... saw something.
At the end of the dark corridor where Borch had almost gone.
In the pitch-black darkness beyond the reach of their lamps.
There were a pair of glowing blue eyes.
They weren't the eyes of an animal. Those eyes had spiral patterns that rotated slowly.
And those eyes were staring at Riven.
"Rianor," Riven called via the helmet radio, his voice tense. "We aren't alone."
"Something's been watching us this whole time."