They didn't get a break.
Barely a day had passed since the rare kill, and Hexin and Ha-Yoon were already being moved. No explanations. No warning. Just a silent escort flanked by five heavily armed guards, their faces obscured by masks.
"Where are we going this time?" Hexin asked cheerfully, gooey hands swinging by his sides. "Is it a surprise? I love surprises! Unless it's, like, a jump scare. Then I just kinda... split."
None of the guards answered. Ha-Yoon walked beside him in silence, hands in his pockets, his posture stiff. Something felt off. They weren't being taken to the usual sectors. No one else was around. Just long, empty corridors of concrete and flickering lights.
Hexin leaned closer to Ha-Yoon. "Do you think they're finally taking us to that luxury spa dimension?"
"No," Ha-Yoon muttered. "But they're taking us somewhere important."
And they were.
Because just beyond a reinforced black door, beneath the heart of the facility where the floors had no numbers, there was something else waiting.
Protocol 7.
The door opened with a low, mechanical groan, revealing a room bathed in green light. The air buzzed faintly. The scent of metal and ozone stung their noses.
In the center of the chamber stood a circular platform, etched with glowing runes, cables coiled like veins along the floor. Around it were monitors, control panels, and glass walls overlooking what looked like… another facility underground.
"Whoa…" Hexin breathed. "Okay, this isn't the spa, but it's fancy."
A voice cut through the air like a knife.
"You're not here to sightsee."
Seo-jun stepped into view, arms crossed, flanked by three higher-ups in long coats bearing Protocol insignias. His expression was unreadable, but his eyes flicked toward Ha-Yoon, then Hexin.
Hexin's grin widened instantly. "Junnie! Did you miss us already? That was fast—"
"Quiet," one of the higher-ups snapped. A woman with silver-rimmed glasses and a pinched expression.
Ha-Yoon stepped in front of Hexin slightly, protective. "Why are we here?"
The higher-up gestured to the platform. "You two killed something that shouldn't have been in that dungeon. That creature was part of a containment breach. One of the early Protocol 7 trials."
Seo-jun's tone was flatter than usual. "You weren't supposed to survive. Let alone bring back the corpse."
Hexin tilted his head. "So… you're welcome?"
"Protocol 7," the silver-glasses woman said coldly, "was an abandoned monster hybridization project. Too volatile. Too unpredictable. But the fact that one of its rejects found its way to a lower-level dungeon—and was killed by two experiments—means something else is wrong."
Ha-Yoon narrowed his eyes. "You think someone let it out."
Another higher-up nodded grimly. "Possibly. Or something far worse."
Seo-jun opened a folder, flipping through images of the corpse they had dragged back. Acid-scarred skin. Triple-layered jaws. Spinal ridges.
"There were similarities to failed Protocol 5 hybrids," Seo-jun said quietly. "And traces of psychic residue… possibly from Protocol 6."
Hexin blinked. "Wait, I thought those were just scary rumors. Like, ghost monster science."
"They were real," Ha-Yoon said. His voice was hard. "Protocol 5 was the symbiote integration one, right? Turned hosts into fused freaks or exploded them from the inside."
"And Protocol 6 warped their minds," Seo-jun confirmed. "Telepathy. Illusions. Madness. It broke more test subjects than it helped. Both were deemed failures."
"And yet," the silver-glasses woman added, "they still bleed into our current systems. Including Protocol 7."
"So what," Hexin said, goo limbs crossed. "You want us to clean up your messes now?"
"You're being moved to the D-Zones," Seo-jun said, tone neutral. "You've been reassigned. Permanently."
"D-Zone?" Hexin blinked. "Ooooh, does the 'D' stand for 'Delightful'? Or maybe 'Definitely-Going-to-Die'?"
No one laughed.
One of the guards leaned in. "D-Zone dungeons are where we send B-rank hunters. Some of the creatures there were made by Protocol 5, 6… and the remaining fragments of 7."
Hexin's grin faltered, just a bit.
Ha-Yoon straightened. "You're using us as test subjects again."
Seo-jun's eyes met his. "No. You're being observed."
Hexin tilted his head. "That's different?"
"Not really," Ha-Yoon muttered.
---
They were moved again after the briefing—to a special wing on Floor -3, where the air felt heavier and the walls hummed softly. Their room was larger but colder, stripped of warmth.
Ha-Yoon sat on the edge of the bed, flipping through his worn-out diary. It had his cramped handwriting, lists of monsters, observations, short phrases. Hexin peeked over his shoulder.
"I like that page," Hexin whispered, pointing at a small doodle of a leafy plant next to the words: Quiet places are good.
Ha-Yoon looked at him. "You still keeping yours?"
Hexin proudly lifted a small, goo-covered notebook from his chest, where it had been protected in a membrane. "Of course! Inspired by you, remember? I even wrote about our knight-slime combo battle. Want to read?"
Ha-Yoon smirked faintly. "Later."
Hexin flopped beside him. "You know, I liked the color green before I even knew what it meant. But after I saw your hair the first time—I decided it was my favorite. Still is."
Ha-Yoon blinked. "That was years ago."
"I'm a very loyal slime."
Ha-Yoon didn't say anything, but his gaze softened just slightly.
---
The next dungeon wasn't like the others.
They stood in front of a massive gate, its stone surface carved with monster sigils and glowing lines. The mission was clear: Enter. Locate the mana core. Eliminate threats. Return.
Except this time, the threats were ranked. And the moment the gate opened, the air itself howled.
Hexin bounced on his feet, excited. "This smells like… danger and barbeque."
Ha-Yoon gripped his weapon. "Stick close."
As they entered, monstrous shapes slithered across the ceiling. A thick mist blanketed the stone floor. Shapes moved in the shadows—more than one. Bigger than anything they had seen.
One of them lunged.
Hexin reacted fast, his body stretching and twisting to form a barrier. The impact sent him flying, but he rebounded with a delighted laugh.
"It tickles!"
Ha-Yoon's blade flashed, severing the leg of the creature that struck. Black fluid hissed as it hit the floor.
Then came more. A wolf-like hybrid with horns and stitched skin. A snake with arms and three heads. And further down… a boss. D-rank. Towering. Breathing fire.
But they didn't stop.
Hexin threw himself into chaos with wild, unpredictable moves—splitting, twisting, tangling monsters up in goo as Ha-Yoon slashed with calm precision.
Teamwork.
Strategy.
Trust.
The monsters screamed.
They screamed louder when Hexin screamed back.
----
By the end, they stood covered in acid and ash, surrounded by corpses.
Ha-Yoon wiped blood from his cheek. "You okay?"
Hexin bubbled. "Never better! Except maybe slightly melted. But that's normal."
When they returned, Protocol was already watching.
Seo-jun stood waiting near the gate.
"Another one," he said.
Ha-Yoon nodded.
Hexin waved tiredly. "Junnieee! Missed you."
Seo-jun didn't respond right away. Then he said, "Next time, try not to scream like a banshee. It triggered three traps." In a calm yet cold tone.
Hexin gasped. "You were listening?"
A faint twitch at the corner of Seo-jun's mouth.
The higher-ups were impressed, but cautious. The report that went up was filled with terms like combat compatibility, experimental synergy, and reliable unpredictability.
Protocol 7 had failed once.
But now?
They saw potential.
------------------*.✧ᘛ⁐̤ᕐᐷ｡*ﾟ-----------------------
It was cold.
Even in the new room—larger, quieter, with clean sheets and walls that didn't smell like rust—the cold stayed with Ha-Yoon. Not the kind that came from air, but the kind that lived in your bones.
He sat on the edge of his bed, flipping through his diary. Page after page of cramped notes, battle tactics, monster descriptions, entries in sharp, steady handwriting. There was a doodle near the corner of one: a rough sketch of a woman with long green hair, eyes closed, a faint smile.
She.
She had been dead for years, but Ha-Yoon remembered her clearly. Her voice, soft and warm like sunlight through water. Her hands brushing his hair back when he cried. Her smile, even when she looked tired. His biological mother—half-monster, half-human. Hunted. Disliked. Beautiful.
He had been four when she died.
And then his father—light brown hair, gray-blue eyes—followed her. A bullet in the head. Love and grief, too heavy.
Ha-Yoon didn't remember the blood. Just the silence afterward.
Then came the second mother. She didn't have green hair. But she had warm hands. Her husband smiled when he read bedtime stories. They gave him a normal life for a while—until a car crash stole it all away.
And then the aunt and uncle.
Cold. Distant. Desperate for money. They didn't hide their hatred for his adoptive parents, nor their disgust at what he was. It was no surprise when he was sold.
He'd been called a lot of things since then.
Experiment 091.
Monster-child.
Freak.
But never boy. Never son.
---
Ha-Yoon was stronger now. He didn't know how or why. The growth was subtle—his reflexes sharper, his blade faster, his wounds healing just a little more quickly than before. His vision in the dark had improved too. But the higher-ups noticed. They gave him better gear. Fewer restraints.
Hexin had changed too.
Not in a human way—he was still a gooey, wobbly creature of yellow-orange and black—but something inside him had shifted. More focused. His chaos had direction.
Together, they were becoming useful.
Dangerous.
Valuable.
---
They were eating better now. Not well—but better. No more moldy bread or stale rice. There were eggs sometimes. Soup with seasoning. They were allowed five extra minutes in the shower, and once, they were even given socks.
Privileges.
Ha-Yoon didn't trust them.
He'd seen how the others looked at them now—some with envy, some with hate. The hybrids who looked less human were treated worse, shoved, mocked, left behind when injured. Hexin got the worst of it. Still, he never complained. He talked to everyone like they were his friend.
Like he didn't notice the hate.
But Ha-Yoon noticed.
He always noticed.
---
They were called again. Another dungeon. A C-tier this time, bordering B. Dangerous.
Ha-Yoon watched Hexin bounce beside him as they walked.
"They're trusting us with more stuff now," Hexin said. "Like, real missions. Kinda makes me nervous. And excited. Mostly excited. But also a little gooey in the guts."
Ha-Yoon didn't respond at first.
Then: "Don't get reckless."
"I won't. Not with you around."
They stepped into the preparation room. Guards were already waiting. One of the newer ones gave Ha-Yoon a hesitant nod. Respect. Because of their kills. Because of what they'd brought back.
Because they were no longer just expendable.
---
The dungeon felt different.
Alive.
The walls pulsed faintly with mana. The monsters were quiet at first—then quick. Hexin was a blur of color, sticky limbs and laughter that echoed like a war cry. Ha-Yoon moved like shadow. Clean. Efficient. He didn't shout. He didn't smile.
He killed.
Because it was the only thing they expected from him.
Because it was the only thing he was allowed to do.
---
Later, they sat in their room again. Hexin was scribbling in his notebook, humming.
Ha-Yoon stared at the ceiling.
"You still think they'll let us out someday?" he asked.
Hexin paused. "Maybe not like... out-out. But maybe somewhere with trees. I like trees. And green stuff."
"...Me too."
Hexin smiled. "Because of me? Or because of her?"
Ha-Yoon closed his eyes.
"Both."
Hexin went quiet.
He didn't need to ask who "she" was.
And Ha-Yoon didn't need to say it.
The ghosts stayed between them. Silent. But not unacknowledged.
---
Outside, the facility prepared.
D-level threats were stirring.
And the hybrids, the ones less human—the ones with claws and fangs and scales—they were being assigned worse missions, harder jobs. Some didn't come back.
But Ha-Yoon and Hexin did.
Every time.
And System Protocol was watching.
They were watching.