Sensory Overload

The corridor of infection and neural hypersensitivity ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠stretched endlessly. The lights flickered at regular intervals, but the power wasn't fully restored. Some sections were completely dark, as if something might be crouching within. Bloodstains on the floor trailed in one direction. I steadied my breathing and followed the drag marks. Unfortunately, the sounds of the infected pointed the opposite way. I kept the gun low but ready to raise at any moment. My wrist and elbow angles felt natural. No memories, yet my body was already optimized for combat.

Damn. I tried to avoid the infected and ended up heading straight toward them. A lab nameplate hung on the wall: Third Biosynthesis Lab. The word "synthesis" brought back the image of the infected creature from moments ago—its ribs splitting open, internal structures rearranging. That wasn't a simple infection. It was a deliberate design with a purpose, and this was the failed result.

At the end of the corridor, the automatic door stood wide open. Inside was a spacious laboratory. Peering in, I saw glass shards scattered across the floor and several experimental capsules tilted and broken. Nothing remained inside. Just as I was about to turn back carefully, a sound came from near the ceiling. Looking up, one of the ceiling panels trembled slightly. Then it tore open, and something dropped through.

It landed on the floor, barely maintaining a human shape. Its neck was unnaturally long, the spine stretched so the head hung forward. The mouth was split open to the ears, the tongue dangling long enough to touch the floor. It had two eyes, each looking in different directions. Its leg joints bent in reverse. The moment it saw me, it extended its neck even further. Vertebrae protruded one by one as the head shot toward my face in an instant.

I stepped back and fired. The bullet pierced its neck, but that elongated structure wasn't mere muscle. The wound twisted and sealed almost immediately.

Annoying regeneration ability.

It screamed, calling for its infected companions. As if on cue, another creature crawled out from behind the empty capsules. This one moved on all fours. Its upper body was humanoid, but four limbs had grown below the pelvis where its legs should have been. Its fingertips were thin and needle-like.

Two. No, three.

Another one rose from the corner of the lab. Its chest was split open, ribs writhing inside.

Immediately available? So evolution happens in an instant. I caught my breath and stared at the window floating in my vision. Options appeared.

What did I need right now? After a brief moment of thought, I chose.

Threat Prediction.

In an instant, my vision changed. The movements of the three infected overlaid with red lines. Their trajectories for the next three seconds appeared faintly. The long-necked one approached from the right. The quadruped closed in low from the left. The chest-split one charged straight ahead.

I sprinted forward. The chest-split creature's ribs opened again, and tentacles shot out along the predicted path. I twisted my body to dodge, then pressed the pistol against its chest and fired three rounds instead of one. Its internal structure ruptured. Mucus and organs sprayed everywhere.

Five bullets left.

At the same time, the quadruped lunged from the left. I evaded its attack and drove my elbow down hard onto its crown. A dull thud echoed, but it didn't stop. The long-necked one dropped from above, its spine whipping like a lash. I ducked low. Its skeleton grazed over my head and sent the quadruped flying.

Three shots to reliably take down each one. But at this rate, I'll be one bullet short for the last.

I dashed in the opposite direction. While the quadruped struggled after colliding with its own kind, I had an opening. The long-necked one chased from behind. Threat Prediction was still active. It felt like I had eyes in the back of my head. I dodged its attacks by a hair's breadth and slipped into its ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠embrace, firing three rounds into its chest just like before. Two bullets remained.

The quadruped rose again. With multiple legs, it closed the distance faster than the others. Just as I prepared to respond, someone burst around the corner of the corridor outside the lab and opened fire. A rifle—single shots, not automatic. The quadruped ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠took a round to the head and turned toward the newcomer, only to receive several more bullets straight into its exposed chest. It collapsed forward and stopped moving.

Only then did I see who had entered. A black ponytail. A form-fitting black bodysuit clung to her body, connected to cover even her face. Though it looked thin, I could see micro-pads embedded at the joints, chest, and thighs. Impact-absorbing structure. Likely combat-grade equipment.

Human. For the first time, I recognized an existence different from myself. Her gun barrel immediately pointed at me. I raised mine as well. In the brief standoff, her gaze traveled down from my face, scanning the torn lab coat and exposed skin.

"A test subject?"

Her voice was low and composed. I didn't answer. The text only I could see in my vision had updated.

The rate had risen to 5%. Still, the fact that it announced combat termination meant I wouldn't have to fight the woman in front of me. While I remained silent, three more infected approached from the corridor I'd come from, drawn by the gunfire. So soon after combat ended?

"Can you fight?"

I nodded.

"Good. Then let's survive first."

Text appeared in my vision.

This felt far more real than vague numbers. I accepted that I'd have to fight alongside a stranger. She pulled the trigger first, filling the corridor with gunfire. Her precise shots targeted leg ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠joints, dropping one infected. I moved immediately, kicking open the first creature's chest and emptying my remaining two rounds inside. From behind, she spoke.

"Center of the chest. That's the weak point, different from a normal heart."

I already knew. Yet her words strangely narrowed the psychological distance between us. The second infected charged at her. I kicked it and used the momentum to leap backward toward the woman. It was an escape route calculated with Threat Prediction. I must have kicked too hard—my back slammed into her chest. The Kevlar bodysuit pressed against me through the blood-soaked fabric of my coat. Solid, yet the body heat beneath was unmistakably human. Even that brief contact made my heart race.

The infection rate had suddenly increased. I didn't know why. The woman behind me stepped aside and fired. Whether she was a marksman or the suit provided aiming assistance, her single shots struck the infected's weak points with precision. The second and then the third fell the same way. The fight lasted less than thirty seconds.

She looked at me and asked, "You're not from this facility, are you?"

"I don't remember anything."

"Recognition name?"

I hesitated briefly before answering. "N221."

"……I see."

She lowered her gun. "I'm Kang Seorin."

She gave me her name. A sign of trust.

"Your face is red. Is the infection progressing?"

Her hand rested on my shoulder. Even through the lab coat, my body flinched at the contact.

"My vision's shaking. Are you really okay?"

"……My nerves have become overly sensitive. External contact seems to raise the infection rate."

I answered honestly. My skin sensations were excessively open. The fabric brushing inside the lab coat, air seeping through the torn sections, body heat that wouldn't subside.

"Don't touch me."

I pulled away from her hand. Though not visible, her clothes might also be stained with infected blood or fluids from her journey here. That was probably the cause.

"The infection made your nerves hypersensitive."

Kang Seorin grabbed my tattered lab coat and pulled it open. Cold air touched my skin directly. I swallowed a breath. I could feel her gaze sweeping over my chest. Beneath the skin, a faint line pulsed with light in rhythm with my heartbeat.

"What is this?"

"I don't know either."

She took another step closer. The faint scent of synthetic fibers from her bodysuit mixed with the warmth of human body heat beneath. My heart beat faster.

Why did it rise again? There was clearly no external threat. "It went up again just now, didn't it?"

She raised her hand. As if particles dispersing, her gloves automatically peeled away, revealing bare hands. Then that hand touched my chest. At the warm sensation, the glowing line beneath my skin began to flow toward it. It felt like electricity. My skin tightened, muscles contracting minutely.

My breathing grew ragged. Not from lack of air, but because my senses had sharpened to the point where everything felt overwhelming. She spoke softly.

"Calm down."

"……Let go and talk."

"Look at me."

She brought her other bare hand to my chin, forcing my gaze to meet hers. The section covering her face disappeared as well. A beautiful face hidden beneath was revealed. Dark eyes. Though sharp in shape, her pupils trembled slightly up close. She was tense too.

This time, her suit began to vanish just like when it revealed her bare hands—wrist, elbow, shoulder, chest, navel. As my eyes locked onto her now half-naked upper body, she pulled me into a tight embrace.

"W-what!?"

My chest was pressed firmly against hers. It felt as if two hearts were beating in sync. "Is the number still rising?"

I couldn't answer. Instead, my heart raced even faster.

It was rising. When I nodded in confirmation, she pressed her body even closer. I reflexively grabbed her waist. It wasn't intentional. I simply felt like I might fall backward. Yet my hands clearly encircled her waist. The trained muscles and elasticity of her body were palpable beneath my palms. Her breathing paused momentarily, but she didn't push my hands away. Instead, she held me tighter, closing the distance further.

"……Every stimulus has a threshold. At first you get excited, but eventually you get used to it."

After a moment's hesitation, I embraced her in return. The lab coat had already fallen to the floor. Our faces crossed, chins lightly brushing shoulders.

"This is just stabilization work. Got it?"

"……Yeah."

"Follow my breathing. Your heartbeat will sync up."

She whispered. I forced myself to regulate my breathing as she said. Inhale, exhale. Her chest rose and fell, the rhythm vivid through our contact. Following that rhythm, my heart gradually calmed.

It had dropped a little. Her words had been true. We remained in the embrace for several minutes.

"Completely stabilized."

"That's a relief."

She stepped back first. As she withdrew, the suit restored itself, covering her skin again except for her face. I felt a slight pang of disappointment. Still, the fact that she didn't cover her face this time suggested she had lowered her guard toward me.

"This was treatment," she said. "Don't misunderstand."

Yet the tips of her ears had turned red. I said nothing. My heart still remembered her rhythm.