3. Echoes in the SCADA

The Sublevel hummed with the low-frequency buzz of signal jammers and bad coffee.

Dan Kuroki had claimed a corner booth beneath a dead neon sign that once read “Open 24 Hours.” Now it flickered sporadically, casting erratic pink light across his gaunt face. He had three laptops open, their screens forming a semicircle of data, and his fingers moved between keyboards with the nervous energy of a man who saw closing walls in every IP address.

“You look worse than this morning,” Sera said, sliding into the booth.

“I’ve been tracing the cryptogram.” Dan didn’t look up. “The rice paper. The sumi ink. That’s not digital. That’s theater. Someone wanted you to know they’re old-school. Someone who knew Kwan personally.”

Sera pulled out the crumpled envelope and laid it on the table. “Can you lift prints?”

“Already tried. The paper’s too porous, and the envelope was wiped clean with alcohol. But I found something else.” He turned one of the laptops toward her. “The ink. Sumi ink is made from soot and animal glue. Different manufacturers have different carbon isotope ratios. This ink matches a batch produced by a small artisan shop in the Insadong district. They only sell to calligraphers and a few very specific government clients.”

“Government?”

“The Ministry of Maritime Affairs still uses handwritten commendations for retiring officers. Old navy tradition. The shop supplies their ceremonial ink.” Dan’s eyes met hers. “Kwan Oh-seok was investigating the Ministry when he died. Specifically, a procurement deal for patrol boats that never materialized. The money vanished into shell companies in the Tosei Islands.”

Sera felt the past reach forward and tap her on the shoulder. She had spent four years trying not to think about Kwan’s final investigation. The documents he had shown her, the sources he had cultivated, the night he had called her at 3 AM, voice tight with excitement, saying he had found the missing link. He was dead forty-eight hours later.

“Someone from the Ministry is watching me,” she said.

“Watching, and warning. The cryptogram wasn’t just ‘don’t dig deeper.’ It was written in a cipher only you and Kwan knew. That’s not a threat. That’s a message from someone who wants you to know they have the right to warn you. A colleague, maybe. Or a rival.”

“Or a killer trying to spook me off the trail.”

“If they wanted you dead, you’d be dead. They know where you live. They got the envelope into your pocket while you were inside a crime scene. That’s close enough for a knife, let alone a letter.”

Sera sat with that uncomfortable truth. She was being handled, not hunted. Someone was trying to steer her, and she didn’t know whether to be grateful or terrified.

“Tell me about Riko’s malware,” she said, changing the subject to something she could attack. “The SCADA exploits. How does a twenty-three-year-old dropout build something that sophisticated?”

Dan cracked his knuckles and pulled up a new screen. The malware’s code sprawled across the display, thousands of lines in a language Sera recognized as ladder logic—the programming standard for industrial controllers.

“That’s the question that’s been bothering me,” Dan said. “Riko Narita was a control systems prodigy at the New Gyeongseong Institute of Technology, but she dropped out before her final year. Her academic record shows she specialized in water treatment automation, not electrical grid protocols. She could have learned, but not this fast. Not this clean.”

He highlighted a section of code. “This subroutine here—the one that maps a building’s internal wiring using only public permit data—that’s military-grade algorithm work. I’ve seen similar code before. It was in a classified briefing about North Hanseong cyber capabilities. The Red Phoenix Group, they called it. State-sponsored hackers who specialize in infrastructure sabotage.”

Sera’s stomach tightened. “You’re saying Riko is working with a foreign intelligence agency?”

“No. I’m saying someone gave her the tools. Someone with access to very advanced code. Someone who wanted to see what would happen if you handed a weaponized SCADA exploit to a grieving sister with nothing left to lose.” Dan leaned back. “She’s not the architect. She’s the test case.”

The implication spread through Sera’s mind like ink in water. Riko’s purification campaign wasn’t just personal revenge. It was a field trial. Someone was using her grief to beta-test a weapon, watching to see how effectively it could kill, how long it could evade detection, how much chaos it could sow before the authorities caught on.

“Who benefits from destabilizing the city’s grid?” Sera asked.

“Who doesn’t? Rival corporations. Political factions. The Tosei Islands independence movement. The North Hanseong cyber command. Pick your boogeyman. But the real question is: why New Gyeongseong? Why now?”

Sera thought about the timing. The monsoon season, when humidity made electrical surges more lethal. The election cycle, with the gubernatorial campaign saturating the news and distracting the police. The Oreore Channel, a perfect hunting ground of anonymous villains. All the pieces fit too neatly.

“This was planned,” she said. “Not just Riko’s part. All of it. The malware distribution. The target selection. The cover-up at KEPCO.”

“KEPCO,” Dan repeated. “The internal memo I found—the one ordering engineers not to investigate anomalies—it was signed by a director named Yoon Sang-chul. Before KEPCO, Yoon worked at the Ministry of Maritime Affairs as a procurement officer. The same ministry that bought phantom patrol boats. The same ministry your mentor was investigating.”

The threads were pulling together into a rope, and the rope was tightening around something dark at the center of the city’s power structure.

“I need to talk to Yoon,” Sera said.

“You need to stay alive. Yoon has connections to people who made Kwan disappear. If you start poking around the Ministry again, you won’t get a warning letter next time. You’ll get a funeral.”

Sera stood up. “Then come with me. You’ve been hiding in this bunker for three years, Dan. When are you going to stop hiding?”

Dan stared at his screens for a long moment. Then he closed all three laptops and stood, his phoenix tattoo seeming to flex as he straightened his shoulders.

“There’s a KEPCO substation in the Mullae district,” he said. “Yoon works late on Thursdays. We can catch him before he leaves.”

They took Dan’s car, a battered electric sedan he had modified with aftermarket signal scramblers and a Faraday cage in the trunk. The rain had intensified, turning the streets into black mirrors. Sera watched the city slide past through the water-streaked window—the neon signs of noraebang clubs, the dark hulks of abandoned factories, the endless rows of apartment blocks, each window a screen, each screen a potential portal to the Oreore Channel.

“Why did you help me three years ago?” Sera asked. “The cryptocurrency case. You didn’t have to testify. You could have fled to the Tosei Islands like everyone else.”

Dan kept his eyes on the road. “Because you were the only one who asked. Not demanded. Not threatened. You just asked. You treated me like a person instead of a tool.”

“Is that rare?”

“In my line of work? It’s nonexistent. Hackers are either weapons or liabilities. Nobody cares about the person behind the keyboard. They just want what you can do for them.” He glanced at her. “You’re different. You actually see people. Even the broken ones.”

Sera thought about Riko, alone in her cathedral of dead screens, talking to a stuffed rabbit with one eye. She thought about Izumi, whose entire life had been reduced to a folder on a hard drive. She thought about the thousands of anonymous users on the Oreore Channel, each one a human being typing cruelty from somewhere in the dark.

She wasn’t sure seeing people was a gift. Sometimes it felt like a curse.

The KEPCO substation was a windowless concrete block behind a chain-link fence, its transformers humming with the energy of a small city. Dan parked across the street and disabled the car’s transponder.

“Yoon’s car is still in the lot,” he said, pointing at a black sedan with government plates. “He should come out within the hour.”

They waited. The rain drummed on the roof. Sera’s phone buzzed with a notification, and she glanced at it instinctively.

It was a message from the Oreore Channel. A direct message, sent to an account she hadn’t created. The sender was “UsagiAdmin.”

The message read: “You visited the arcade. You spoke with Riko. You’re trying to decide whether to save Koji Tamura. Let me help you decide.”

Attached was a file. Sera opened it.

It was a screenshot from Tamura’s private messages on the Oreore Channel, dated three months before Izumi’s death. The message was directed at a user named “FoxFire01,” and it read: “The Narita girl is almost broken. One more push and she’ll crack. I want it to be memorable. Something the news will pick up. The community deserves a spectacle.”

Below that, FoxFire01 had replied: “What do you have in mind?”

Tamura’s response: “I’m thinking a livestream. We convince her to do it on camera. Imagine the view counts.”

Sera felt her stomach turn inside out. Tamura hadn’t just harassed Izumi. He had planned her suicide. He had tried to turn it into content.

The message from UsagiAdmin continued: “Still want to save him? There’s a camera in the Horizon Towers electrical room. The feed will go live at 8:15 PM. Tune in or don’t. But remember: every time you type a comment, you’re voting for what kind of world you want to live in. Riko voted for justice. What will you vote for?”

Sera closed the phone. Her hands were shaking.

“What is it?” Dan asked.

“They know everything. Where I’ve been. Who I’ve talked to. They’re watching me in real time.”

Dan grabbed her phone and examined it. His face went pale. “Your phone’s been compromised. They’ve installed a remote access trojan. Probably through the Oreore Channel link you clicked last night. They’ve been tracking your location, reading your messages, listening to your conversations.”

“Can you get it off?”

“Not here. The trojan is embedded in the firmware. I’d need a clean room.” He turned off the phone and removed the battery. “From now on, we use burners. No internet. No GPS. We’re flying blind until we figure out who’s on the other end of this.”

Sera stared at the KEPCO building, its lights blurring in the rain. The hunter had become the hunted. The rabbit was no longer just watching—it was leading her by the nose, steering her toward a choice she didn’t want to make.

Yoon Sang-chul emerged from the substation at 7:45 PM, briefcase in hand, umbrella raised against the downpour. He was a heavy man in his sixties, with the careful posture of someone who had spent decades navigating bureaucratic hierarchies. Sera intercepted him before he reached his car.

“Director Yoon. My name is An Sun-hee. I need to ask you about the SCADA anomalies.”

Yoon’s face registered shock, then anger, then something that looked like fear. “I have no comment. KEPCO has issued its official statement. The grid is stable.”

“The grid is being used to kill people. You know that. You signed a memo ordering engineers not to investigate. Why?”

Yoon glanced around the empty parking lot, then lowered his voice. “You don’t understand what you’re getting into. The memo didn’t come from me. It came from above. Way above.”

“The Ministry of Maritime Affairs?”

Yoon flinched. “How do you know about that?”

“I know about the patrol boats. I know about the missing money. I know about Kwan Oh-seok.”

At the mention of Kwan’s name, Yoon’s composure cracked. “Kwan was a friend. We served together in the naval reserves, thirty years ago. When he started investigating the procurement fraud, I warned him to stop. He didn’t listen. And now he’s dead, and I’m signing memos I don’t want to sign because the people who killed him will kill my family if I don’t cooperate.”

“Who are they?”

Yoon shook his head. “I can’t. If they even suspect I talked to you—”

“They already know I’m here. They’ve been tracking my phone. They probably know I’m talking to you right now. The only chance either of us has is if we expose them before they can cover their tracks.”

Yoon stared at her for a long moment. Then he opened his briefcase and pulled out a folded document. “This is the original anomaly report. The one Jin Seong-min wrote before he was fired. I kept a copy. It proves that the grid intrusions started six months before Riko Narita’s first kill. Someone was testing the system long before she got access to it.”

Sera took the document. “Who was testing it?”

“I don’t know. But the first test happened at Horizon Towers. The same building where Koji Tamura lives. Whoever is behind this, they’ve been targeting Tamura from the beginning. Riko isn’t the hunter. She’s the weapon they aimed.”

The implications crashed over Sera like a wave. Riko thought she was avenging her sister. But someone else had chosen her targets. Someone else had given her the tools. Someone else was using her grief as camouflage for a much larger operation.

“Why Tamura?” Sera asked. “Why him specifically?”

Yoon looked at his watch. “It’s almost 8 PM. Tamura’s family has left the building. He’s alone. If you want to know why he was chosen, you’ll have to ask him yourself. But you’d better hurry. The purification window opens in fifteen minutes.”

He climbed into his car and drove away, his taillights vanishing into the rain.

Sera turned to Dan. “We need to get to Horizon Towers. Now.”

Dan shook his head. “That’s exactly what they want. They’ve been herding you toward this moment since they left that hard drive on your doorstep. You’re playing into their hands.”

“Maybe. But if Yoon is right, Tamura isn’t just a monster. He’s a piece of the puzzle. Someone wanted him dead before Riko ever heard his name. If I can find out why, maybe I can find out who’s really behind all of this.”

Dan stared at her for a moment, then tossed her a burner phone. “Fine. But we do this my way. No calls. No messages. No digital footprint. We go in, we talk to Tamura, we get out before the rabbit strikes. Deal?”

“Deal.”

They climbed into the car and sped toward Gangnam. The rain hammered the windshield, and the city lights blurred into streaks of neon. Sera’s reflection in the window looked hollow and strange, like a ghost trapped between worlds.

The clock on the dashboard read 7:58 PM.

Twelve minutes until the purification.

Somewhere in the dark, a rabbit was watching. And it was smiling.