Sparks flew in the darkness, metal in ringing in every strike. At first glance, it might look like a typical day for a blacksmith apprentice. Except the “forge” was a dungeon—— and that apprentice was mining, not hammering steel.

  “Of all things he could ‘ask’ me for, this is what he came up with”

  He had average looks, unruly hair, and stood slightly taller than most boys of his age. The kind of guy you’d pass in the crowd and forget instantly. If “average” needed a face, it probably borrows his.

  Even back in his village, the adults never bothered using his title— despite him technically having one.

  To them, he was just… that guy with painfully ordinary face. In a strange way, his overwhelmingly ordinariness made him stand out.

  And right now, Yuuto that painfully average apprentice was deep inside the dungeon, mining mana crystal as a “favour” for his master.

  “I can’t believe him!”

  He swung his pickaxe harder, more sparks scattering

  “Almost emptying our stock of mana crystal in one day! Just what he is doing with all of it? Is he eating them or something?!”

  It wasn’t that Yuuto hated his master.

  Annoyed? Absolutely.

  Resentful?

  … Not really.

  The man had taken him. Fed him. Given him roof when he had nowhere else to go. More than that—— he’d accepted Yuuto as his apprentice.

  For that alone, Yuuto was grateful.

  Still… His master’s reckless habits were another story. Leave anything in that man’s hand long enough, and it would disappear. Materials. Tools. Savings. All gone like the wind.

  Which was why Yuuto was the one always stuck with inventory duty.

  Again!

  He let out a hard sigh. “If he won’t change, then the least thing he could is teach me properly… or at least tell me what he is using all those mana crystals for”

  No answer.

  Of course not. The man wasn’t even here.

  He tightened his gripped on the pickaxe and swung again, slowly chipping the massive crystal in front of him.

  His expression remained focused. His thoughts, however were somewhere else entirely.

  *‘How is he doing it? How can he do it without breaking the weapon itself?’.*

  The questions plagued Yuuto’s mind as continued mining.

  In the first place, why was he even in here?

  He was a blacksmith in training—— not some kind of adventurer. Yet here he was, deep inside a dungeon, chipping away at crystal that could explode in any moment. Even his usual master’s so called ‘favours’ didn’t involve this level of danger.

  His gaze fell to the crystal before him.

  Mana Crystals.

  Crystallization of stagnant mana fused with atmospheric impurities. They formed only under very specific conditions—deep dungeons thick with monsters, or battlefields drenched in magic and blood.

  Blacksmiths can use various materials in their work, like copper, iron, steel, and if skilled enough the legendary mithril.

  Mana crystals?

  That was another field entirely.

  They were far more suited in mana tech, acting as power sources, conduits, and core for wand. Trying to directly forge them into conventional weapons without a large amount of preparation and knowledge can only lead to one outcome.

  Failure… violent Failure

  Their very internal structure contradicts foreign materials. Force the issue, and they explode in your face.

  And yet ——

  In his master’s hand, those “rules” meant nothing. Working with those volatile materials looked as easy as breathing.

  It was absurd.

  Yuuto still remembered the first time he saw it.

  Back then, he had only meant to pass by the forge. He was still new to blacksmithing, bare familiar with more than the most basic techniques.

  Yet, something stopped him.

  The narrative has been taken without authorization; if you see it on Amazon, report the incident.

  The steady rhythm of hammer striking metal echoed through the night, slow and deliberate. The sound drew him before even realized it.

  Curiosity stirred.

  Before he knew it, he was already peeking through the narrow slit beside the workshop.

  And there, he witnessed it something he would never forget.

  He saw his master place a raw mana crystal directly into the furnace.

  No preparation.

  No stabilizing runes.

  No safety tools.

  The crystals should have exploded.

  Instead, the flames bent around it—— almost as if they were obeying him.

  Yuuto froze.

  By the time he snapped out of it, the glowing crystal had already fused into the liquid metal.

  His master suddenly glanced through the door. Their eyes met through the narrow slit of his helmet.

  The firelight reflected in his master’s gaze, making it glow faintly in the darkness. Without a word, the man simply gestured.

  *Go back to bed.*

  And just like that, the moment ended.

  Since then, no matter how carefully Yuuto watched, observed, no matter how much he begged to be taught. His master refused to explain a thing.

  “…Just what does he wants me to do?”

  His strike faltered.

  “…I messed up”

  Yuuto scrunched his face, cursing his own impatience. He’d gone deeper.

  Due to his own eagerness to finish early and head home. He hadn’t noticed how far he’d descended. The air in here felt tighter, heavier.    Luckily, no monster attacked him during his mining frenzy.

  His gaze dropped to the staircase below, he let out a resigned sigh

  “I guess there is no harm in taking a break in here”

  He sank against the nearest stone wall. Cold seeped through his clothes. Digging in his bag, he pulled a drink. Water slid down his dry throat, giving his tired body energy once more.

  Just as he reached for his carefully saved snack, something streaked past him.

  “…?”

  He froze.

  Silence.

  Yuuto’s eye darted left and right.

  Nothing.

  Only darkness. The same suffocating darkness he’d grown accustomed to since entering.

  *“I must be imagining it”*

  No.

  His instincts disagreed.

  Watching.

  Waiting.

  Slowly, Yuuto’s hand crept toward the hilt of his short sword. He tightened his grip, raising his vigilance.

  Again—- something brushed past his ear. He was sure of it.

  He turned sharply.

  Nothing.

  *“What… was that? Just the wind?”*

  There was no wind in a dungeon like this. It’s impossible. The sound came again—faint at first. Almost distinct. Easy to dismiss if he wanted to.

  Then it shifted.

  What had been a little more than a whisper sharpened into something harsher.

  A dry, crackling noise—

  Like rain hammering against a roof during a thunderstorm

  *“Of all times, why… now?” He muttered. “Is this because no monster showed up earlier?”*

  Yuuto glanced back, searching for an escape route if thing went south.

  The staircase could get him out-but only to the third floor, which was far riskier than staying here. He weighted his options.

  Fight…

  or run?

  His instincts screamed only one word.

  Danger.

  He has only the barest basics of fighting monsters, the only reason he made it this face was because of the dungeon unusual emptiness.

  Without the luck—- he’d already be back home.

  His body was tensed, muscles coiled like springs, ready to burst forward at a moment’s notice. He knew he could at least defend himself for a while. Maybe long enough to escape—- but the monster in front of him?

  One strike, and he was done for.

  He gripped his sword tighter that he ever remembered, knuckles white.

  Seconds stretched into minutes.

  Heartbeat grew louder.

  Time slowed.

  The fear in his chest deepened with every passing moment.

  Then——

  The sound shifted.

  “…Huh?”

  The crackling softened.

  And transformed.

  *“Hymn?”*

  It was the last thing he expected

  A melody drifted through the corridor. Gentle. Soft. The kind of lullaby a mother would hum to their child There was no malice in it. No distortion. No obvious threat—-only a quite urging to come closer.

  And yet… something about it felt wrong.

  If he had been on the surface, he might have welcome it.

  But he wasn’t.

  He was in a dungeon—one of the most dangerous places known to mankind.

  Every instinct in his body screamed at him. Nothing in the dungeon is harmless. Nothing appeared without a reason. Only a complete idiot would stand still and let that sound draw closer.

  Yuuto scanned his surrounding, eyes sharp, breath shallow. But he couldn’t pinpoint the source. The hymn reverberated through the walls, the ceiling, the floor- bouncing, echoing, swallowing direction itself.

  It was everywhere.

  Which meant it could be anywhere…

  Then—-

  It stopped.

  “Just what is happening…?”

  He didn’t lower his guard. If anything, he tightened his grip.

  His senses strained to their limits. His gaze snapped from crack to shadow, from wall to ceiling, refusing to overlook even the smallest detail. In a place like this, one mistake was it all took.

  One mistake, and you were dead.

  And yet… It didn’t matter.

  Without a warning, the ground beneath him shattered.

  A violent crack split the stone apart, and the floor collapsed as if it had been hollowed all along.

  “——?!”

  Yuuto’s body dropped.

  The world flipped.

  For a brief, impossible moment, everything froze. Sound vanished. Color drained. Even his heartbeat seemed to disappear.

  There was only a sensation of falling.

  And a single thought echoing in the void of his mind——

  *I don’t want to die*

  But the dungeon did not care.

  Stone crumbled. Dust swallowed in the air. The darkness below opened it jaws without hesitation.

  No mercy.

  No warning.

  Just another careless collapse in a place where countless lives had already been swallowed.

  Far below, something waited in the endless dark.

  Not for Yuuto.

  Not for anyone.

  This dungeon simply took.

  And Yuuto——

  continued falling.