Rebate King: I fed them to rule the apocalypse

chapter 6: ghost of the subway

The metal emergency door of the underground market bucked with a heavy, hollow *clang*.

"Ethan," Sarah whispered from the darkness behind me. She was propped against a stack of moldering flour sacks, her hands still gripping the edges of the tactical vest I’d forced onto her. "That’s not the rain. It’s too rhythmic."

"I know," I said.

I didn't turn around. I kept my eyes pinned to the rusted viewing slit of the reinforced door. We had been deep inside the subterranean belly of the old Mapo underground market for six hours. The air down here was thick, smelling of old concrete, damp garlic, and the stale grease of a hundred abandoned street-food stalls. It was dark, save for the faint, battery-powered lantern I’d set on a plastic crate between us.

*Clang.*

The impact was lower this time, near the baseline of the iron frame. I kept the tactical shotgun raised, my finger resting lightly against the trigger. I only had one Dragon’s Breath shell left in the tube. If whatever was outside managed to puncture the steel, a localized explosion in this narrow concrete corridor would cook both of us.

"Is it another one?" Sarah asked, her voice tight, cracking under the strain. "The static... it’s not getting louder in my head. It’s staying flat. Like a hum."

"Then it's not a Lurker," I murmured. "Lurkers don't pace themselves. They hit until they break or the door does."

I adjusted my grip on the shotgun, my eyes scanning the shadows beyond the door. The system interface hung quietly in the corner of my vision, its blue text dim against the dark environment.

**[Current Status: Hidden Underground Sanctuary]**

**[Detection Risk: Moderate]**

Suddenly, the banging stopped. The heavy silence of the market returned, punctuated only by the faint, distant hiss of the storm draining through the street-level grates above.

"Did it leave?" she breathed.

"No," I said. "It realized the door won't give."

A faint, metallic scratching sound echoed from the wall to my left—not from the main entrance, but from the rusted ventilation shaft running parallel to the ceiling.

I spun, leveling the barrel at the square metal grate. The dark metal bars were vibrating. Something was sliding through the narrow duct, moving with a fluid, chilling precision that lacked the frantic scratching of the pale drones we had killed in the alley.

"Ethan—"

"Get behind the crate," I cut her off, my voice dropping to a harsh whisper. "Now."

The ventilation grate didn't pop off. Instead, a long, slender blade—a standard, high-grade military combat knife—slid through the slots, neatly slicing the small iron rivets holding the frame to the concrete. The grate was caught before it could hit the floor, lowered down without making a single sound.

A figure dropped from the ceiling, landing in a perfect, silent crouch in the center of the damp corridor.

It wasn't a monster.

The young woman stood up slowly, brushing a strand of short, bleached-blonde hair away from her eyes. She wore a high-end, waterproof tactical hardshell jacket, reinforced cargo pants, and a customized leather chest rig holding several sleek, black polymer magazines. She didn't look like a scavenger scraping by in the ruins of Seoul; she looked like an operative pulled straight from a private security firm.

But it was her face that made me freeze. Her expression was completely calm, her dark eyes sharp and utterly human, showing none of the vacant horror or crimson infection I’d seen in Raven.

She looked at the shotgun leveled at her face, then glanced past my shoulder toward Sarah, who was trembling behind the flour sacks.

"A 12-gauge tactical pump in South Korea," the girl said, her voice clear, conversational, and completely devoid of fear. She spoke fluent Korean, but her accent had the distinct, polished cadence of someone from the wealthy districts of Gangnam. "And a pristine military-grade supply crate in an abandoned market. You've been busy, Ethan Vale."

My heart skipped a beat, the cold adrenaline surging through my veins. *Another one.* First Raven, now her. They knew my name before I even opened my mouth.

Before I could speak, the blue interface flashed violently, a fresh block of text unrolling across my retinas.

**[Target: Min-Ah Cho]**

**[Identity: System User — 'The Logistician' (Variant 04)]**

**[Trust Level: 15% (Calculated Neutrality / Business Interest)]**

**[Warning: Target possesses an active system. Rules of engagement have been modified.]**

The air in my lungs went cold. *An active system.* The text didn't say she was an enemy, but it didn't say she was an ally either. She was a user. Like me.

"Who the hell are you?" I asked, keeping the front sight aligned with the bridge of her nose. I didn't care about her system; if she made a move toward her chest rig, I’d pull the trigger.

"Min-Ah," she said simply, sheathing her combat knife with a clean, practiced motion. She held her hands out away from her sides, palms open to show she wasn't reaching for a firearm. "And I'm not here to fight you. If I wanted to clear this room, I would have dropped a tear-gas canister down the vent before coming down myself."

"You're tracking me," I said, my voice tightening. "How do you know my name?"

Min-Ah let out a low, dry chuckle, her eyes darting to the blue interface floating in front of her own face—a movement I only recognized because I did the exact same thing. "The same way you know mine, I assume. The network logs every active user within a five-kilometer radius when a major event occurs. You blew up the Mapo Broodmother with an encrypted weapon variant. The ping practically lit up my map like a flare."

Behind me, Sarah let out a sharp gasp. "Another user? Ethan... what is she talking about? What network?"

Min-Ah shifted her gaze to Sarah, her eyes narrowing slightly as she took in the dark, violet lines tracing along Sarah’s jaw. A flash of genuine recognition—and caution—crossed her features.

"Ah," Min-Ah murmured, her tone turning serious. "You found a Carrier. And you've already triggered her first resonance. No wonder your rebate values spiked enough to manifest military hardware."

"Explain," I demanded, lowering the shotgun by a fraction of an inch but keeping my posture rigid. "What do you mean by 'variant'? What is this system doing?"

"You really don't know, do you?" Min-Ah took a step closer, stopping exactly at the boundary where the lantern light faded into the dark. "You think you're special because you got a little cheat menu that gives you guns when a girl doesn't trust you? You're playing the 'Rebate King' game, Ethan. But your rules aren't my rules."

She tapped her own temple.

"My system is the *Supply Chain Index*. I get points based on resource retention and territorial control. The guy three districts over in Yongsan? He has the *Executioner's Ledger*—he gets stronger every time he terminates a survivor. There are dozens of us in Seoul alone, each assigned a different script."

The revelation hit me like a physical blow. The system wasn't a unique miracle dropped into my lap to help me survive. It was a distributed software package. A test grid.

"Why?" I asked, my jaw tightening as the cold, strategic part of my mind began to piece the horror together. "Why give different rules to different people?"

"To see which algorithm performs best under stress," Min-Ah said, her voice dropping to a chillingly practical whisper. "The apocalypse isn't a disaster, Ethan. It’s an environment. A sandbox. The systems are farming our choices, our stress, and our trauma to optimize something larger. And the women you're targeting? The 'Carriers'?"

She pointed a finger directly at Sarah, who shrank back under the gaze.

"They aren't victims. They're the hardware. They are the mobile nodes that anchor the system to this world. The more they change, the more the environment stabilizes for the network."

"She's a human being," I said, though even as the words left my mouth, they felt hollow. I had already treated Sarah like a tool in the alley to get my flashbangs.

"For now," Min-Ah countered sharply. "But look at her neck. The sync rate is already rising. If you keep using her to trigger your rebates, she’ll stop being Sarah Jenkins by chapter twenty, and she’ll become a terminal. A living antenna for whatever is coming down from the sky."

Silence fell over the corridor, heavy and suffocating.

I looked from Min-Ah’s calm, calculating face back to Sarah. Sarah was staring at her own hands, her fingers trembling as she watched the dark, violet veins pulse beneath her skin. She looked up at me, her eyes wide with a terrifying question. She realized it now. Every time she doubted me, every time I used her fear to get a weapon, I was driving the needle deeper into her veins.

"So," I said slowly, turning back to Min-Ah. "You didn't crawl through a ventilation shaft just to give me a lecture on system mechanics. What do you want?"

"An alliance," Min-Ah said, a sharp, business-like smile returning to her lips. "The Yongsan user—the one with the *Executioner's Ledger*—has already cleared two districts. He’s hunting other users to absorb their core data. He’s moving toward Mapo now. If he finds you alone with a high-sync Carrier, he’ll slaughter you both and take your shotgun to use as a prop."

She stepped forward, extending a hand toward me.

"My logistics, your firepower. We fortify this market, use your rebate loop to manufacture an army's worth of gear, and we take him out before he crosses the river. What do you say?"

The blue interface in front of my eyes suddenly flickered, replacing the standard status screen with a massive, golden prompt that filled my entire vision.

**[Ding! Faction Proposal Received.]**

**[Current Option:]**

**[1. Accept Alliance with Min-Ah Cho (Trust Level: 15%). Benefit: Access to local resource maps.]**

**[2. Reject Alliance and Attempt Hostile Transaction. System Note: Gifting an item to an active System User with low trust will trigger an unstable, corrupted rebate multiplier.]**

I stared at her extended hand, my mind calculating the variables with a chilling, ruthless speed. An alliance was safe. It was logical.

But the system didn't reward safety. It rewarded the edge of the blade.

"An alliance sounds great, Min-Ah," I said softly, a dark smile slowly forming on my lips as I reached into my tactical vest, pulling out the second M84 flashbang grenade I’d received from Sarah’s panic.

I didn't pull the pin. Instead, I flipped the heavy, military-grade canister through the air, letting it drop straight into her open palm.

"Here," I murmured. "A token of goodwill."

Min-Ah’s eyes widened in instant, horrific realization as her fingers instinctively caught the live ordnance. "Wait—what are you doing?!"

The interface exploded into a violent, weeping purple light.

**[Transaction validated! Host has gifted an advanced item to an Active System User!]**

**[Target Trust Level: 0% (Immediate Betrayal Detection).]**

**[Corrupted Rebate Protocol Initialized... Value calculation: Severe Malfunction!]**