Rain fell long after the hearing ended.
Not heavily.
Just enough to blur the courthouse windows into gray reflections.
Seo Hae-in sat alone in her office.
The jacket she had worn in court now rested neatly across the back of her chair. She had changed into another black outfit before returning—a high-collared knit tucked into tailored trousers, the lines clean, understated, and severe. Her wardrobe never chased attention. It removed distractions.
The only light came from her desk lamp.
Three files remained open.
Custody Records.
Security Logs.
Visitor Registry.
Everything pointed to the same conclusion.
No unauthorized visitor had entered the detention center.
And yet...
Someone had.
A knock interrupted the silence.
Detective Kang stepped inside carrying a cardboard archive box.
"I borrowed these."
She looked at the faded labels.
"From where?"
"Storage."
He placed the box on her desk.
"The prison keeps paper records after digital ones are archived."
"You think the computer records were altered."
"I think computers are easier to edit than paper."
That earned him another one of Hae-in's almost-smiles.
"You've been listening."
"I work with you."
Dust drifted into the air as Kang opened the box.
Old visitor logs.
Maintenance reports.
Staff schedules.
Nothing looked important.
Which was exactly why they read everything.
Minutes became an hour.
Then another.
Neither complained.
The silence between them had changed over the past week.
It no longer felt awkward.
It felt efficient.
Hae-in stopped turning pages.
"Kang."
He looked up immediately.
"What date was the father's visitor supposed to arrive?"
"The evening before the murder."
She slid one yellowing maintenance report across the desk.
"Read this."
He frowned.
"'Audio inspection. Cell Block C. Emergency communication system tested between 20:10 and 20:37.'"
He looked up.
"So?"
She tapped the report.
"No technician signed out."
Silence.
His expression slowly changed.
"...Someone performed maintenance..."
"...without recording who."
Kang immediately reached for another folder.
"This can't be enough."
"It isn't."
"But it's the first document that acknowledges someone was there."
She nodded.
"The system recorded maintenance."
"Not a person."
He leaned back.
"So whoever entered..."
"...used the maintenance schedule."
Neither of them spoke.
Because it made perfect sense.
People questioned visitors.
They rarely questioned workers.
The detective's phone rang.
He answered quickly.
After less than thirty seconds, he looked at Hae-in.
"The second man."
Her attention sharpened.
"What about him?"
"He's gone."
The detention center was already in lockdown when they arrived.
Officers rushed through corridors.
Doors slammed shut.
Voices echoed from every direction.
"What happened?"
The warden met them outside the infirmary.
"He disappeared during a medical transfer."
"Disappeared?"
"He never reached the examination room."
Kang frowned.
"Someone walked him out."
The warden's silence was answer enough.
Hae-in stood in the corridor.
Her eyes moved slowly.
Security camera.
Fire exit.
Service elevator.
She wasn't looking for the missing man.
She was looking for the mistake.
Then she noticed something.
One security camera faced the hallway.
Another covered the elevator.
Between them...
A narrow section of corridor.
Invisible to both.
She measured it with her eyes.
Four steps.
No more.
Just enough space for someone to change direction unnoticed.
"Who designed this building?"
The warden blinked.
"What?"
"The blind spot."
He hesitated.
"I... don't know."
She nodded once.
"You should."
Back at the office, Kang replayed the security footage.
The second man appeared on screen.
Calm.
Walking beside a nurse.
He reached the blind spot.
Then—
He never appeared again.
The corridor beyond remained empty.
No struggle.
No panic.
Nothing.
It was as though he had simply...
ceased to exist.
Kang rubbed his forehead.
"I hate this case."
"You hate mysteries."
"I hate impossible mysteries."
She watched the frozen frame.
"They're rarely impossible."
He glanced toward her.
"Then what are they?"
She answered without looking away.
"Engineered."
She rewound the footage again.
Frame by frame.
The nurse.
The orderly.
The second man.
A janitor pushing a supply cart.
"Stop."
Kang paused the video.
"What?"
"The cart."
He zoomed in.
Cleaning supplies.
Buckets.
Mops.
Nothing unusual.
Until Hae-in pointed toward the lower shelf.
One corner of a polished black leather shoe was visible beneath the hanging cloth.
Someone else was inside the cart.
Hidden.
Neither of them spoke.
Because if that was true...
The escape had been planned long before the transfer began.
Night had settled over the city by the time Kang left.
Hae-in remained.
She pinned the new evidence to her board.
Maintenance.
Blind spot.
Supply cart.
Every answer created another question.
She stepped back.
The wall was becoming crowded.
She hated crowded walls.
It meant she was still missing the center.
Her phone vibrated.
Unknown number.
She let it ring once.
Twice.
Then answered.
No greeting.
Only breathing.
This time...
she spoke first.
"You lost one of your pieces today."
Silence.
Then the familiar distorted voice answered.
"No."
A pause.
"We recovered him."
The line went dead.
Hae-in lowered the phone slowly.
Recovered.
Not rescued.
Not escaped.
Recovered.
She wrote the word across the whiteboard.
Then circled it.
Hard.
Because people recover property.
Not human beings.
Outside her office window, the rain finally stopped.
But the city felt quieter than before.
As if it, too...
were listening.