The next morning, Hana arrived at school with the strange feeling that someone was watching her.
She looked around the hallway.
Nothing.
Students were rushing to class, teachers were carrying books, and the usual morning noise filled the building.
Still, she couldn't shake the feeling.
When she reached her classroom, she found a small envelope on her desk.
Her name was written across it.
Hana.
She slowly picked it up.
Before she could open it, Min-jae appeared beside her.
"Don't."
She looked at him.
"Why?"
"Because someone wants you to."
He took the envelope carefully.
"We should open it together."
Hana nodded.
Inside was a photograph.
Her heart skipped.
It was an old picture of Min-jae's sister, Ji-ah.
But this time, she wasn't alone.
Standing beside her was Joon-ho.
And behind them was Mr. Kang.
Hana stared at the photograph.
"There has to be something we're missing."
Min-jae turned the photograph over.
There was writing on the back.
Room 302. After lunch.
Hana looked at him.
"That's an empty classroom."
"I know."
"Then that's where we're going."
Min-jae nodded.
"But we're not going alone."
After lunch, they waited until the hallway became quiet.
Room 302 was at the end of the third-floor corridor.
The door was unlocked.
Hana pushed it open.
Dust floated through the sunlight coming from the windows.
There were no desks.
Only old chairs stacked against the wall.
Min-jae walked toward the teacher's desk.
"Look."
A small key was sitting on top.
Hana picked it up.
"There are numbers written on it."
17.
Min-jae looked around.
"Seventeen…"
"Maybe a locker?"
They searched the room.
Nothing.
Then Hana noticed a row of old lockers outside the classroom.
She counted.
Fifteen.
Sixteen.
Seventeen.
Locker 17.
Min-jae inserted the key.
The lock clicked.
Inside was a small notebook.
Hana recognized it immediately.
"The black notebook."
Min-jae stared at it.
"My sister's."
He picked it up carefully.
The first few pages contained ordinary notes about school.
Then they reached a page with a date three years earlier.
Min-jae began reading.
His expression changed.
"What does it say?"
He handed the notebook to Hana.
She read the page.
I found out who started the rumor. I know the truth now. But if I tell everyone, someone else might get hurt. I need to meet them tomorrow.
Hana looked up.
"Who was she going to meet?"
Min-jae turned the page.
There was no answer.
The next page had been ripped out.
Hana frowned.
"Someone removed it."
Min-jae nodded.
Then something fell from the notebook.
A tiny photograph.
Hana picked it up.
Her eyes widened.
It showed four people.
Ji-ah.
Joon-ho.
Mr. Kang.
And—
Hana's breath caught.
She knew the fourth person.
Min-jae saw her expression.
"Who?"
Hana slowly turned the photograph toward him.
His face went completely pale.
"No…"
"What?"
He stared at the picture.
"That person wasn't supposed to be there."
Hana looked at him.
"Why?"
Min-jae's voice dropped to a whisper.
"Because they told me they weren't even in the country three years ago."
A sound suddenly came from the hallway.
The classroom door began to close.
Hana and Min-jae turned toward it.
Someone was standing outside.
They couldn't see the person's face.
But they could hear their voice.
"You finally found it."
The door slammed shut.
And the lock clicked from the other side.