Dungeon Mutation
I fixed a sharp gaze on the direction where the boss’s mana pulsed, then turned to Han Seo-ah beside me and spoke in a grave voice.
“You need to head back to the cabin right now.”
“What about you, Seo-jun?”
“I’ve got to check what the hell’s going on over there.”
“…Will you be okay alone?”
“Don’t worry. I’m only going to scout.”
“But…!”
“Just do as I say.”
My unyielding tone finally won out. Clutching the bag of supplies I had handed her tightly against her chest, she spun and sprinted toward the cabin with everything she had.
Once her back had receded into the distance, I pulled the black iron sword the Dullahan had dropped from my inventory, kicked off the ground, and raced away.
I reached the vicinity of the castle. Keeping my body as concealed as possible, I tried to make out what was happening on the far side—and the sight of the colossal skeleton army massed before the gates sent a chill racing down my spine.
Holy shit. How many of them are there?
Even a rough count put them well past several thousand. And among them, a handful of skeletons were dragging humans along.
“S-save me… please…!”
One of the men thrashed desperately, wailing. When I got a clear look at his face, I recognized him—Park Yu-jin’s ex-boyfriend.
One of his arms had already been torn clean off and blood poured freely from the stump while his legs scraped uselessly across the ground, clutched in a skeleton’s grip.
“Yu-jin…! Yu-jin!! I’m here! Save—ghhk!”
Seong-jin’s scream never finished. A Skeleton Knight seized his head in a merciless grip.
“Aaaagh…! Aaaahhh!!”
More skeletons hauled over people I had never seen before. They were already half out of their minds, eyes wide with terror as they scanned their surroundings.
Must be another party that got trapped in the dungeon.
I stayed low in the shadow of a tree and watched. The skeletons herded their captives one by one onto a massive makeshift altar erected in front of the castle gates.
Dozens of hunters—easy to count more than that—screamed in pure panic while Skeleton Knights ringed the altar, cold axe-blades raised to cut off every avenue of escape.
Once it looked as though every last person had been gathered in one place, the castle gates groaned open with a ponderous, metallic shriek.
Creeeeak—!
A thick black fog billowed out from within the gates and swallowed the entire altar. From the heart of that fog, a colossal mounted warrior far beyond any ordinary skeleton revealed itself in all its dread majesty.
Clad head to toe in pitch-black armor, a greatsword gripped in one hand, blue soul-flames flickering where a head should have been.
It was a Doom Knight—the superior evolution of a Dullahan.
…Huh. Looks doable, actually.
At that moment the Doom Knight slammed its greatsword into the ground. The grotesque runes carved into the altar floor blazed blood-red.
“A-aaaagh!”
Vitality drained from the bodies of the hunters on the altar, turning into black smoke that was sucked straight into the Doom Knight’s armor.
The earth shuddered once. The Doom Knight raised its blade high.
It looked for all the world like a signal to advance for the entire legion. The thousands of skeletons arrayed below the altar clacked their jaws in unison and unleashed a deathly roar.
The dungeon boss vanished back into the castle, and with the Dullahan at their head the skeletons began their march.
That direction…!
They were heading straight for the cabin—the safe zone.
Goddamn it.
The legion’s pace was far faster than I had expected. They never tired, never detoured around obstacles; they simply surged in a straight line toward the cabin.
I spun on my heel and sprinted back toward the safe zone at blistering speed.
The cabin door came into view in the distance. The problem was that the blue barrier that had marked the safe zone was gone without a trace.
I wrenched the door open. Everyone inside whipped around to face me at once. Han Seo-ah’s eyes flew wide and she rushed over first.
“Seo-jun! What happened? Your face is—”
“Pack your things and get out. This place isn’t safe anymore.”
“What? What are you talking about?”
“Thousands of skeletons are heading this way, so move it!”
Silence dropped over the room like a bucket of ice water.
“Th-thousands…?”
Park Hyun-woo’s voice shook violently. Choi Jae-hyuk was already cowering in a corner, trembling like a leaf.
“If we don’t move right now, in ten minutes this place becomes a banquet table for those bone bastards. Where are Yu-jin and Ha-eun?”
“Th-they’re in the inner room…”
I brushed past Seo-ah and strode into the back room. Park Yu-jin and Kim Ha-eun, who had been out cold, must have woken from the commotion; they were clutching the covers to hide their disheveled bodies.
“Both of you, up.”
They rose in confusion, but one look at my grim expression and they instinctively understood this was an emergency.
The party hastily gathered their gear and left the cabin.
“Where are we even going…?”
Baek Do-yoon asked in a voice thick with fear.
“The boss room.”
“Are you insane? You just said thousands of them are coming from that direction! Going there is like walking straight into a tiger’s den!”
Kim Ha-eun shot Baek Do-yoon a look of pure contempt.
“Wow, look at this idiot. Seo-jun’s saying the castle is empty right now.”
“Then…?”
Han Seo-ah seemed to grasp my intention.
“Exactly. This is our chance to escape. While the legion is out clearing the safe zone, we take down the boss left alone.”
“She’s right… When a dungeon mutates, making a run for the gate inside the boss room is standard procedure.”
Hope flickered in the party’s eyes at Seo-ah’s words.
“From this point on, everyone but me focuses on supporting me from the rear.”
Han Seo-ah closed in right behind me.
“…Is this really going to be okay? You said a Doom Knight is still inside the castle.”
“We can handle it. In fact, this is the perfect window—while it’s separated from its army.”
My firm answer silenced them. They simply picked up the pace.
Before long, the distant clatter of thousands of bone joints colliding rolled across the earth—the march of the skeleton legion.
“Oh my god…”
Park Hyun-woo, who was carrying a wounded comrade on his back, broke out in a cold sweat and stared in horror.
“…If we’d just stayed at the cabin without a second thought, by now…”
He couldn’t finish the sentence. His body shook. A little later and they would have been crushed to nothing beneath that procession of death.
The closer we drew to the castle, the thicker and colder the air became.
“That…”
Han Seo-ah spotted the altar off to the side. Her face drained of all color as she clapped a hand over her mouth.
The mummified husks of hunters lay twisted in grotesque postures across the ground.
Only skin clung to bone after every last drop of life force had been drained; their mouths hung open as if still screaming the agony they had felt while alive.
“Anyone you know?”
“Yeah… they were our teammates.”
Seo-ah’s voice was thick with tears. Among the corpses was the ruined body of Seong-jin, Park Yu-jin’s ex.
“……”
The others froze in terror, but I never stopped. I simply adjusted my grip on the black iron sword. There was no room for pity for the dead.
I kicked the massive castle gates open with one foot.
BOOOOM—!
Dust and wind billowed outward. The interior of the castle looked like a vast tomb.
“From here on I take point. Baek Do-yoon, you cover the rear. Choi Jae-hyuk, you stay behind me and protect the healer and the mage.”
Baek Do-yoon clenched his teeth.
“Why the hell should I take orders from—”
“Do-yoon!”
Han Seo-ah snapped at him from behind. He forced his head to turn away.
I stared at him with open disgust. Even in a situation like this he was still blinded by that pitiful pride, unable to sort out his priorities. Pathetic.
Why does Han Seo-ah even hang around with trash like that?
I wondered just how much she must love him to keep walking beside something like him.
“Everyone keep your eyes open and follow me.”
With me at the front we advanced down the corridor. The boss room lay at the highest point in the center of the castle, where a massive concentration of mana could be felt.
Using the mana pouring off the Doom Knight as a compass, I pressed forward.
“Seo-jun… do you really think there’s a gate in the boss room?”
Park Yu-jin lightly tugged at the hem of my clothes, voice laced with anxiety.
“There will be. If there isn’t… we’ll figure that out later.”
The party swallowed hard and fell silent. Perhaps because the castle was so empty, no real fighting broke out inside.
We reached the boss room without incident.
Mana cascaded like a waterfall from beyond the enormous steel doors. I rested a hand on the handle and looked back.
“Seo-ah, start pre-casting your magic. Yu-jin, the second combat starts, slap the buffs on me.”
“Got it.”
“Understood.”
“And Baek Do-yoon, Choi Jae-hyuk—you two protect those two with your lives.”
“……Fine.”
“……”
Choi Jae-hyuk still wore a vacant expression, but the fear of dying must have won out; his trembling hands tightened on his shield. Then I looked at Park Hyun-woo. He was carrying a wounded teammate and couldn’t fight at full strength. As for Kim Ha-eun…
“What am I supposed to do with you?”
“W-what about me…!”
Most of her skills were assassin-type, and as a D-rank she couldn’t land any meaningful damage on a boss anyway. Stealth or ambush against a high-tier boss’s razor-sharp senses would be pure suicide.
“Just cheer from the back.”
“Hey, I can fight t-too, you know…”
“Really?”
Kim Ha-eun flinched, then immediately tucked her tail between her legs.
“…Hehe. I’ll just cheer from the back, then.”
I turned my head again and faced the massive doors head-on.
“We’re going in.”
I opened them without hesitation.
BOOOOOOM——!
The heavy steel doors slid aside and a blast of cold wind slapped my face.
The chamber inside was far larger than I had imagined. The ceiling soared high overhead; blood-red runes carved into every pillar glowed faintly.
The floor was as smooth as black marble. In the exact center sat a colossal throne of bone and black iron, sharp spines jutting in every direction.
And seated upon that throne was the entity.
The Doom Knight.
It lounged with one leg crossed, tapping the armrest with a finger as if bored out of its mind.
Even without a head, it felt as though those empty sockets were raking us from head to toe.
Beside it stood a massive warhorse reduced to pure bone. Black mist seeped between its ribs, and the same blue flames burned in its empty eye sockets.
I drew the black iron sword. At the same time Park Yu-jin began casting buffs over my body.
“Haste! Strength! Sword Enchant: Holy!”
“Seo-jun, I’m ready!”
The instant Seo-ah’s shout rang out, I kicked off the floor and exploded forward.
“Seo-ah, hit it now!!”
“Got it!”
BOOM—!
My body shot toward the Doom Knight so fast it left no afterimage.
Still seated on the throne, the Doom Knight reached out at a speed the eye could not follow and snatched up the greatsword that had been leaning against the armrest.
CLANG—!
Black iron sword and greatsword locked together, unleashing a shockwave that shredded eardrums. The marble floor spiderwebbed beneath us from the impact alone.