[ Parallel Scene: Seoul Metropolitan Police Headquarters — Second Floor ]
At that same moment, while police cars rolled out one after another from the station gate, Choi stood by the second-floor window, watching their headlights stretch across the street below.
He didn't move.
The office behind him was quiet — computers left on standby, screens glowing faint blue, half-drunk coffee cups still sitting on the desks.
Everyone had already rushed out.
Only the low buzz of the city came through the glass.
His reflection showed his pale eyes for a second — almost no color, just empty.
Ghost Eyes.
That's what they called him when they thought he couldn't hear.
He exhaled softly and turned away from the window.
The chase outside wasn't where things would start.
It would be in the data — signals, screens, the kind of traces people never saw.
His shoes clicked quietly down the hallway, each step slow and steady.
At the end of the corridor, light was coming out from a half-open door — the glow of monitors, the low sound of voices through headsets.
Cyber Division.
Inside, the room was a mess of light and noise — monitors flashing, officers shouting over each other, phones ringing somewhere in the back.
The room smelled like coffee and sweat, that same stink that always comes after a long night.
Choi walked in quietly. No one noticed him right away. Everyone was busy pulling data, checking CCTV, running cross-matches that led nowhere.
Then one of them turned, eyes widening a little.
"Detective Choi! You're here—"
He didn't answer. Just kept walking, hands in his pockets, eyes moving over the monitors — watching what everyone was doing without saying a word.
In the corner, Kim sat with his sleeves rolled up, typing fast, eyes half-dead from the screen glow.
His desk was buried under paper cups, snack wrappers, and half-finished reports — the usual chaos.
He was supposed to be pulling CCTV footage and prepping reports for the Chief. Nothing more, nothing less.
Just another night for him.
Choi's eyes paused on him for a second.
Kim was still typing, bitting the tip of pen, hair messy, half his shirt untucked like he hadn't slept.
He didn't even notice Choi at first.
"Kim."
The typing slowed. "Yeah, yeah, Chief wants the report again, right?" Kim mumbled, eyes still on the screen. "You can tell him it's coming. These servers run slower than my grandma's TV."
"Kim Tae-sung."
That made him stop mid-sentence.
He turned his head a little, pen still hanging between his fingers. "Uh… yeah? What's with the full name? Sounds like I'm about to get fired."
Choi didn't reply right away. He leaned closer, the pale reflection of the monitors catching in his silver eyes. "You're done with those CCTV logs?"
Kim clicked his tongue and turned back to the screen. "Almost. Half the feeds are corrupted. Don't tell me the Chief's already yelling again. If he wants a miracle, tell him to buy one."
Choi didn't move. He just kept watching. His voice was calm. Too calm.
"You work faster than our IT team."
Kim gave a lazy shrug. "Guess I just hate paperwork."
"No," Choi said, softly, his pale eyes holding Kim's reflection. "You just hate being boring."
The pen slipped from Kim's hand and hit the desk.
He finally looked up. The light from the monitor cut across his glasses, hiding his eyes for a second.
Kim leaned back in his chair, grin tugging faintly at the corner of his mouth.
"Heh. Guess those ghost eyes really do see more than they should."
Choi's voice stayed calm. "Enough to know you're not just some IT grunt."
He paused, eyes still on Kim. "Or should I say… Null?"
The grin disappeared, wiped away in an instant. Kim froze, his body straightening without him meaning to. The lazy slouch he always had was gone — replaced by the tight, alert stance of someone who just realized they'd been outplayed.
"...You really shouldn't know that name," Kim stated, the joke entirely gone. He was already calculating the origin of the information.
Choi tilted his head slightly. "Null," he said, the word quiet, almost testing it.
"That's what you call yourself, right?"
Kim's eyes lifted, just enough to meet his. The glow of the monitor caught his glasses again, hiding his pupils.
Then, for the first time, a small, real smile crossed his face — one that didn't look lazy or tired.
"Yeah," he said softly. "That's me."
His voice dropped a little lower, almost like a confession.
"Because that's what I leave behind. No trace. No source. Just… null."
He leaned back, spinning the chair slightly with one hand.
"When the system tries to find me, it only gets one result — nothing."
Kim lifted his chin slowly, his eyes narrowing as he finally accepted the checkmate. "Alright, Ghost Eyes. You've established leverage. How'd you know it was me?"
Choi didn't answer right away. He just stood there, the monitor light made one side of his face look blue.
When he finally spoke, his tone was calm — almost conversational.
"You talk too much when you lie, Kim. But you gave yourself away by admiring the opposition's work."
Kim blinked. "What?"
He didn't answer. He couldn't. He was just silent for a moment.
Choi's eyes stayed on Kim's face — quiet, steady like they'd already seen through him, and unreadable enough to make anyone hesitate.
He just thought to himself — 'Truth and lies always looked different to me. Like feelings showing in colors only I could see.'
"The first time you came to the field," Choi continued, ignoring the interruption. "The Shin Han-soo bank-manager case."
Kim blinked slowly, processing. "...The one where the laptop was hacked after the murder?"
"Yeah." Choi's tone didn't change. "The one where someone hacked his laptop after killing him. Moved a few million offshore."
He took a step closer, hands still in his pockets.
"Most techs flinch when there's blood on the floor, or when they deal with loss. But your focus wasn't on the victim's data or the loss of funds."
His fingers moved over the keyboard, slower with every word, like his thoughts had drifted away from the screen and were now somewhere else — listening to Choi instead.
Choi paused for effect, letting the weight of the accusation settle. "You were glued to the compromised laptop, your eyes tracking the logs, and you looked elated. Not triumphant, but genuinely thrilled."
Kim was silent now, his shoulders slowly dropping as he realized Choi had not only noticed, but had cataloged the moment.
"The killer was an amateur, a script-kiddie using a pre-packaged exploit," Choi continued, reciting the internal script Kim had run that day. "But the bank manager's own system defenses were solid. You saw the elegance in the defense, and the disappointment in the weak attack."
Choi then took one step closer. "And while you were digging through the victim's laptop, you muttered something you probably don't even remember."
Choi's eyes lifted, catching Kim's.
"'If this idiot had even bothered to alter the MACE data or spoof his TTL count, I'd still be digging through junk.'"
Choi looked straight into Kim's eyes.
"The moment you said that, I knew. You weren't a police analyst who job was to collect evidence. You were a master technician critiquing the methodology of the criminal. You were excited by the challenge of the trace, not the tragedy of the case."
The moment he heard Kim mutter those words back then, he already knew — Kim wasn't just pulling the data.
He was tracing it. Following the signal like someone who'd done it a hundred times before.
Choi took a small pause in middle.
Choi said, his tone sharper now.
"That's how a genius hiding behind glasses sounds when the job's too easy."
Kim blinked slowly, a faint grin tugging at his lips.
"You remember everything, don't you?" he said, voice low.
Choi didn't answer. He didn't have to.
He remembered everything Kim did that day — his words, his face, his expression, even how the screen light hit his eyes.