The Hidden Mithril Cavern
The cool, damp air of the mine brushed against Hwian’s arms like unseen fingers as he ventured deeper into the tunnels. Most of the lanterns had been smashed, leaving the passage dim and shadowed. Hwian walked steadily, boots crunching over debris while his eyes scanned the chaotic surroundings.
There are more of them than I expected. The state of these tunnels is awful.
Sharp gouges riddled the walls, as though the rock itself had been sliced apart by blades. Pickaxes lay scattered everywhere, sheared cleanly in half and abandoned by the miners who once wielded them.
Cave Mantis were exactly as the name suggested: mantis-shaped monsters that dwelled in caves.
They ranged from roughly fifty centimeters to a full meter in length. Their metallic forelegs could shear through stone for consumption, and they possessed the ability to reinforce their exoskeletons and blades by absorbing the metal content.
They usually traveled in swarms and possessed strong territorial instincts. Under normal circumstances, the standard response upon discovery was to seal the tunnels immediately.
The reason they could not do so this time lay in the unique nature of the Kelib Silver Mine.
It’s more beautiful than I imagined. This is my first time entering before the collapse.
A quick glance revealed silver veins threading through the walls. The faint lantern light caught on the lodes, making them sparkle like stars scattered across a night sky even in the gloom.
In this world, silver held value far beyond mere artistic beauty. Thanks to its exceptional magic conductivity, it served as a core material for all manner of magic tools and spell arrays. The high-purity silver of the Kelib Silver Mine was nothing short of a national treasure for the Adonia Kingdom.
Nor was silver the only thing found here. Refining it inevitably produced lead as a byproduct. With good fortune, gold could be extracted as well. With even greater luck, one might mine metamorphic rock infused with accumulated ley-line mana—that is, mana stones.
Few people would abandon a literal treasure vault over a handful of mantises. Those desperate or fearless enough had rushed into the mine despite the outbreak, and the gruesome scene Hwian had witnessed at the entrance was the result.
A choice made to survive had only shortened their lives. The irony was bitter.
“Hmm… Yes, we should be reaching their territory soon.”
He cut his thoughts short as the atmosphere shifted.
The once-silent tunnel suddenly filled with the sound of skittering legs. Hwian adjusted his grip on the sword, loosening it slightly while every muscle in his body coiled tight.
A faint vibration traveled up through his feet.
He held his breath. Then they appeared.
“Quite a few. As expected.”
With a piercing Kiiik—! dozens of Cave Mantis surged toward him. They packed the narrow tunnel shoulder-to-shoulder, pouring forward like ants spilling from a disturbed hill.
The danger could be compared to several dozen children gripping kitchen knives in both hands, teeth bared, charging with murderous intent.
Any ordinary person would have felt both revulsion and terror. Hwian simply curled his lips into a bold, crooked smile.
“Shall we stretch our limbs a little?”
A proper real battle after so long. His first true fight with a live blade since regression.
Slowly, Hwian fed the mana boiling from his heart into every muscle of his body. His flesh pulsed with sudden vitality. Feeling the burning heat and rising exhilaration, he took a powerful step forward.
—!
There was no war cry—only the sharp sound of his breath.
His sword tore through the air and sliced cleanly through a mantis’s hardened exoskeleton. The second strike flowed like water, severing its head. The third severed another creature’s foreleg.
Clear fluid sprayed. Savage insect shrieks followed. Hwian swung his blade with razor precision, kicking away the charging monsters as though savoring every moment of the fight.
…Huu.
When he finally paused, Hwian wiped the sticky fluid from his sword with a casual swipe of his sleeve and resumed walking at an easy pace. Dozens of mantis corpses lay scattered behind him.
“I wonder how things are going outside… There are other adventurers with them, so it shouldn’t be too dangerous.”
Roughly two hours had passed since the subjugation began. Hwian wiped his blade once more and muttered to himself.
The mantises were far more numerous than anticipated. Including the first clash, he had already eradicated three large swarms, and countless lone stragglers roamed every branch of the tunnels.
Strange. The request had been posted some time ago, yet their numbers showed no sign of decreasing. It was no wonder the miners had struggled. Yet separate from that practical concern, a growing sense of unease gnawed at him the deeper he explored.
Even for a large mine, isn’t this excessive?
It was not unheard of for a massive mantis nest to form inside a major mining complex. But something felt different this time. There were mantises everywhere, yet no matter how far he searched, he could not locate a single nest.
There was no source.
The realization left Hwian with a deep, instinctive wariness.
“…Hm.”
Still, there was little he could do about it. With no better option, he continued deeper, cutting down only the mantises that appeared before him.
The tunnels twisted like a maze. At the farthest end lay a passage sealed off due to insufficient lighting.
Comparing the map he had received with the one burned into his memories from his previous life, Hwian pressed onward step by step.
At last he found the place he sought.
“There it is… Found you.”
The poorly maintained passage was dark and uneven. Yet in its center stood a section of rock wall that strangely emitted light.
“Hup!”
A powerful downward slash left a deep gouge in the unusually thin stone. After several more strikes, he had carved an opening large enough for a person to pass through.
Light spilled from the hole, accompanied by a faint breeze that spoke of a larger space beyond.
Without hesitation, Hwian squeezed through the gap.
“…Ugh. There.”
Ley lines carried mana. Silver possessed high magic conductivity.
It was only natural, then, that the mana flowing through the ley lines would be drawn into a vast silver deposit. That was why mana stones were so common near silver mines—stones transformed by long-term accumulation of magical energy under special conditions.
If that same mana accumulated inside the silver itself rather than stone… what would it become?
“Haha. What a spectacle.”
The answer lay directly before his eyes.
A colossal natural cavern easily dozens of meters high stretched before him. Between towering stone pillars that rose like ancient trees stood an enormous, brilliantly shining ore formation.
An infinitesimal quantity of silver exposed to mana for an unfathomable length of time under extraordinarily rare conditions.
An incomparable, supreme-grade mineral. Holy silver—or magic silver.
A gigantic blue-green raw gem radiating dazzling light.
Mithril rested there.
It’s larger than I expected… At that size, you could build a house with it, never mind forge weapons.
The sheer scale had caught Hwian off guard first. The ore was far bigger than he had anticipated, and the natural cavern surrounding it was vastly more immense than his prior knowledge suggested.
This isn’t a natural world heritage site… it’s something else entirely.
Even with the glow cast by the mithril, the ceiling was so distant it disappeared into shadow. Each of the stone pillars supporting the cavern measured more than ten meters around, forcing any visitor to confront the overwhelming majesty of nature whether they wished to or not.
The hole he had carved looked laughably insignificant against the cavern’s scale.
Shrugging at the pleasant miscalculation, Hwian moved forward.
No mantises here. Is that fortunate or ominous?
Contrary to his expectations, no mantis nest existed in this place either. The mystery deepened, but he chose not to dwell on it.
From now on, he simply needed to chip away at the mithril a little each day. Once that was done, he would have no further business in this mine.
He could craft weapons and secure funds. Perhaps he could even assemble a small mercenary company in preparation for the great war against the Demon King.
Since no one else knew of this place, there was no need to hurry.
With that thought in mind, Hwian continued walking—until suddenly—
“…!”
Voices reached his ears.
Previous visitors?
Instinctively pressing himself behind a stone pillar, Hwian frowned. The appearance of guests who should not exist filled him with considerable alarm.
It would take the miners at least several more weeks to discover this cavern. His memories of world events before the regression were clear; at this exact point in time, this place should have been empty.
A lost adventurer? A tomb robber who obtained information…?
No answer presented itself no matter how he turned the possibilities over. Worse, the murmuring voices suggested there was more than one intruder.
Slowly, he peered out from behind the pillar. He would at least confirm their identities first.
“……Tch. Damn it all.”
The unexpected sight that met his eyes made Hwian click his tongue in irritation.
A group of roughly a dozen figures clad in purple robes stood encircling the mithril, performing some kind of ritual.
The very last people he wanted to encounter in these tunnels.
The cancer of the continent. A congregation of Demon King worshippers.