System Mission: Seduce the Strongest S-Class Hunters or Die Trying!-Chapter 120: [YOUR FAULT!]

Kairo swept the beam of his flashlight across the cavern walls, slow and deliberate, tracing every jagged edge of stone. The light skimmed over dripping stalactites, over black water that seemed to stretch endlessly.

It was quiet.

Too quiet.

"Nothing off so far," he muttered, though his voice was low, his gaze narrowing as he scanned again.

’But isn’t this a little too... quiet?’

In a dungeon, silence wasn’t peace. Silence was the hunter before the strike.

What happened with the leeches already proved that—barely a ripple, barely a sound, until they were already latched on. Even the phantoms hadn’t rushed them; they had simply pulled, whispered, waiting for them to slip.

Not loud. Not aggressive.

’Quiet means I’m not seeing something I should be seeing.’

His grip tightened around his sword, the obsidian edge catching a dull gleam under the red drone light. Blood stirred faintly around his boots, coiling like restless serpents.

The memory of those glowing blue eyes underwater flickered through his mind. Those phantoms had been A-Class, no doubt. Strong, but manageable.

So if the dungeon had climbed higher—

’Does that mean what’s ahead... is an S-Class monster?’

Would it be like the ogres he and Eli faced?Or something worse?

Now that was the question.

Kairo exhaled through his nose, steady. He forced the tension down, letting it coil into readiness instead of panic.

"I still can’t feel anything," he muttered, voice low, nearly drowned by the cavern’s drip-drip. His boots shifted, water splashing softly as he pressed forward, deeper into the dark.

The silence followed him.

’If there’s still nothing, I’ll just go back.’ Kairo thought, his jaw set. As much as he believed something was waiting, maybe—just maybe—it wasn’t going to show itself.

And then—

Preeep!

The sound cut through the silence like a knife.

Kairo froze, sword already snapping up into a ready stance. His blood stirred around his boots, forming ripples. Every muscle in his body locked.

’What was that?’

"Where is it coming from?" he muttered low, his voice carrying a sharp edge.

Preeep!

There it was again. Clearer. Sharper.

A high-pitched sound, like something pressed against the inside of his skull.

Not a growl. Not the hiss of a leech.

Not the distorted whispers of the phantoms.

It didn’t even sound alive.

Preeeeeep!

"Is that..."

Kairo’s brow furrowed, his grip tightening on the hilt. The sound rang strangely familiar—thin, shrill, precise.

"...a whistle?" he breathed, disbelief in his voice.

But that didn’t make sense. A monster’s cry, yes. Some warped mimicry, maybe. But this? A whistle?

Preeep!

The cave’s black walls carried the sound, bouncing it back at him until it seemed to come from everywhere at once. He swung his flashlight in an arc, scanning, sword raised, blood tensing for a strike. Nothing.

Then it happened again.

Preeep!

And this time, he knew.

Kairo’s eyes snapped wide, his breath catching in his throat. He turned sharply, swinging the light back the way he came.

Toward the direction he’d left Mio, Eli, Zaira, and Mel.

The shrill sound carried again, echoing down the tunnel.

Preeep!

"...What the hell...?" Kairo muttered, his stomach dropping.

For some reason, Kairo had a feeling the sound wasn’t random.

It was coming from them.

Something was happening.

▒▓ ▀▄█ ⚠ ▄█▀ ▓▒

A few moments earlier...

"So..."

Eli cracked first. 𝙛𝒓𝓮𝙚𝔀𝒆𝒃𝓷𝒐𝓿𝙚𝓵.𝙘𝒐𝒎

Five minutes of silence weighed on him like stone, and he couldn’t take it anymore. He shifted uncomfortably on the slick rock, turning toward Mio.

"You should... use this time to rest, Mio," Eli said carefully, his voice low in the cavern. "You’ve been carrying them this whole time. Zaira and Mel are still unconscious—you deserve at least a moment to breathe."

Mio didn’t look up. His head stayed bowed, shadows hiding his face. The faint drone light wasn’t enough to catch his expression.

Eli bit his lip, worry creeping in. ’He must really, really be tired...’

Fortunately, Mio spoke.

"...always getting... captain..."

Eli tilted his head. "Hm? Sorry, what was that? I couldn’t hear you." He took a hesitant step closer.

"I said..." Mio’s voice sharpened as he raised it. "It must be nice. Always getting carried by the captain."

Eli froze.

Something about the tone was... wrong. Too flat. Too bitter.

Still, he tried to laugh it off, his hand rising to rub the back of his neck. "I know, right? But honestly, it’s not that nice. At my age, being carried around is embarrassing." He forced a chuckle, hoping Mio would lighten up.

But Mio didn’t laugh. Not even a twitch of amusement.

Instead—

CRACK.

A sharp ache stabbed through Eli’s skull, his head pounding like a spike was being hammered straight into his brain. His ability screamed at him, danger flooding his veins like ice water.

And it was coming from Mio.

Eli’s legs wobbled, forcing him a step back. His yellow eyes widened, panic flickering in them. "M-Mio...?" His voice cracked, barely above a whisper.

Mio finally lifted his head. Slowly. Too slowly.

The faint red glow from the drones slid across his face, and though Eli couldn’t make out every detail, he didn’t need to. He could feel it—like venom dripping into the air.

Contempt. Pure and sharp.

Eli’s chest tightened, his breath catching as Mio’s lips moved.

"This was all your fault."

Eli’s stomach dropped. ’Did he really just... say that? Or is it the phantoms?’

He blinked at him, heart thudding, unsure if he’d even heard right. "M-Mio...? What do you mean?"

Mio finally raised his head. The faint red glow of the drones cut across his face, shadows twisting with every flicker.

His eyes were narrowed, hard—so unlike his usual sharp steadiness. His jaw clenched, teeth grinding, like he was holding back something violent.

Eli’s chest tightened. The voice had been bitter, cutting. It didn’t sound like Mio.

Or maybe it did.

’Are the phantoms still here? Did they get to him somehow? But there aren’t any—I don’t see them.’ His pulse spiked, thoughts spiraling. ’Do they even have the ability to control someone? If yes, why now? Why not earlier?’

No answer came. Maybe it wasn’t phantoms.

Maybe it was exhaustion, the dungeon breaking him down piece by piece.

Eli forced his own voice steady, though his throat felt raw, the words trembling. "You’re tired. You don’t mean that, Mio. Just... breathe, okay? We’ve all been through a lot down here."

But Mio didn’t breathe.

The threads moved. Slowly at first—small twitches, like something restless. Then sharper. Harder. The silver cords vibrated in the dark, scraping faint lines into the rock at his feet.

Danger.

Eli’s instincts screamed. His heart slammed against his ribs. ’He’s about to—’

The threads lashed forward.

Fast. Merciless.

Eli bolted. His boots splashed hard against the water, the noise too loud in the suffocating cave. He stumbled, slipping on the slick stone. His balance shattered—arms flailing.

SPLASH!

The freezing water crashed over him, swallowing him whole. His lungs seized, panic flaring white-hot.

Above, the drone lights caught a deadly glimmer—silver threads, slicing downward toward him like blades.

’He’s...attacking me?!’