Chapter 5: The Letter Under the Door
The black car didn't move.
That was what unsettled Hana the most.
It didn't rev its engine.
It didn't flash its headlights.
It didn't try to hide.
It just sat there across the cracked pavement outside the café, engine quiet, windows tinted dark enough to swallow reflections.
Seojun's gaze stayed fixed on it. Jungho had already shifted slightly, positioning himself between Hana and the window without saying a word.
"They want us to see it," Jungho murmured.
"Or they want us to panic," Hana replied.
Seojun's jaw tightened. "No. This isn't panic. This is a message."
As if on cue, the car's headlights flickered once.
Then it slowly pulled away, disappearing into the city's night traffic as if it had never been there at all.
Silence fell inside the café.
Too quiet.
The flickering fluorescent light above them
buzzed softly.
And then—
A faint sound.
A soft scrape against the floor near the entrance.
All three of them turned at once.
An envelope had been slid under the café door.
No footsteps. No knock.
Just the envelope.
Hana's heart pounded as she walked toward it. She crouched, hesitated for only a second, then picked it up.
Her name was written on the front.
Not printed.
Written.
Pressed deep into the paper, as if the pen had been carved into it.
H A N A.
Jungho locked the door behind them.
Seojun stood close. Not touching her. Just close enough.
Hana opened it carefully.
Inside was a single sheet of paper.
No signature.
No logo.
Just black ink.
She read aloud.
"Curiosity buries the innocent."
Her throat tightened.
She continued.
"Step away from school affairs."
A pause.
Then the final line.
"Or the next funeral will be your fault."
The air felt heavier.
Jungho exhaled slowly. "They're accelerating."
"They're watching," Seojun said quietly.
Hana's fingers trembled—but not from fear.
From anger.
"They think this will scare me?"
"They don't need to scare you," Jungho replied. "They need to pressure you."
Seojun's eyes darkened. "They're shifting responsibility. If someone dies, they want you to believe it's because you interfered."
Hana stared at the letter.
The phrasing.
The tone.
Controlled. Clinical. Detached.
Like it had been written by someone who understood psychology.
Jungho leaned back against the counter. "You need to understand something."
"Tell me."
He looked between her and Seojun before speaking.
"K doesn't operate randomly. Every year, they select one class."
Hana blinked. "What do you mean—select?"
"They focus on one specific class in the school. They observe it for months. Study dynamics. Identify emotional fractures. Social hierarchies. Weaknesses."
Seojun folded his arms. "And then?"
Jungho's voice lowered.
"They isolate one student."
The words landed heavy.
"They don't attack directly," Jungho continued. "They manipulate. Spread rumors. Twist perceptions. Create tension between friends. Amplify insecurities. Teachers unknowingly become part of it. By the time it ends, the target believes the world is against them."
Hana's mind flashed to Joonseo.
The whispers.
The laughter.
The loneliness.
"They make it look natural," Jungho finished.
Seojun's gaze sharpened. "And if the target breaks?"
Jungho didn't answer immediately.
"They lose something," he said finally. "Sometimes reputation. Sometimes family. Sometimes… themselves."
The silence that followed was suffocating.
Hana looked down at the letter again.
"Another innocent will lose his life."
She clenched the paper in her fist.
"Which class?" she demanded.
Jungho hesitated.
Then he said it.
"Third-year Class B."
Hana froze.
"That's happening right now?"
"Yes."
Seojun's expression shifted. "And you're sure?"
Jungho nodded once. "The pattern matches. Social shifts started three weeks ago. Subtle exclusion. Anonymous posts. A teacher suddenly targeting one student more than usual."
Hana's thoughts raced.
"How do you know this?"
Jungho met her eyes. "Because I used to be in that system."
The words hung between them.
Not accusation.
Not confession.
Just truth.
Hana inhaled slowly.
"So they're threatening another student," she said. "And blaming me in advance."
"Yes," Seojun replied. "They want to destabilize you before you move."
Jungho stepped forward. "You can still step back."
Hana looked at him.
Then at Seojun.
Then at the letter.
Joonseo's message echoed in her memory.
I want to live. Help me.
She folded the paper carefully and slipped it into her pocket.
"No," she said.
Her voice wasn't loud.
It didn't need to be.
"If they target one class every year, then we don't wait for the target to break."
Seojun tilted his head slightly. "You're suggesting…?"
"We get into that class."
Jungho's brows furrowed. "Transfer?"
"Temporary placement. Special project. Exchange program. I don't care how."
Seojun studied her. "You're planning to observe them from the inside."
"Yes."
Jungho ran a hand through his hair. "That's risky."
"So is doing nothing," she replied.
The storm in her chest wasn't guilt anymore.
It was strategy.
"They think fear makes people freeze," Hana said. "Let's prove them wrong."
Seojun's lips curved faintly—not a smile, but approval.
"And how," Jungho asked carefully, "do you plan to arrange that?"
Hana's gaze shifted.
Cold.
Focused.
"We don't do it alone."
Jungho understood immediately.
"The detective."
Seojun's eyes narrowed slightly. "You trust him?"
"I don't trust anyone," Hana said. "But he has access. Authority. And he already believed Joonseo's case wasn't right."
Jungho didn't look convinced.
But he didn't argue.
The café lights flickered again.
Outside, the street had returned to normal.
As if nothing had happened.
Hana walked toward the door and unlocked it.
The night air was sharp.
She stepped outside, looking down the empty road where the black car had vanished.
"They want us to hesitate," she said softly.
Seojun joined her.
Jungho followed.
"No more hesitation," Hana continued.
She turned to them.
"We meet the detective tomorrow."
And somewhere in the distance—
Unseen.
A camera lens adjusted its focus.