It was getting late, but I was still awake in bed.
The ceiling fan turned slowly overhead, blending with the sounds of several friends who had already begun to fall asleep. I should have been doing the same.
But my thoughts kept returning to what had happened that afternoon.
“If you go out... you have to follow rules that have never been read aloud.”
The sentence kept circling in my head.
What did it mean?
What rules had never even been read aloud to the dorm residents?
I rolled over and tried to close my eyes.
Five minutes.
Ten minutes.
It didn’t work.
Finally, I sat up and took my phone from beneath my pillow. The time was 11:47 p.m.
I opened the class group chat.
There were no new messages.
Then I opened the dorm group chat.
Nothing.
It was too quiet for a group that was usually still busy at this hour.
I was about to put my phone down when a message came in.
An unknown number.
I frowned.
The message consisted of only one sentence.
“You shouldn’t have asked about the rules.”
My heart began beating faster.
I stared at the screen for several seconds, making sure I hadn’t read it wrong.
Then a second message came in.
“Don’t leave your classroom after the last bell tomorrow.”
My hands felt cold.
I wanted to reply, but before I could type, a third message appeared.
“Unless you want to know what happened to the previous student.”
I stood up immediately.
Who had sent this?
And who did they mean by the previous student?
I looked toward my friends’ beds. They all appeared to be asleep. No one was paying any attention to me.
I looked back at my phone.
The messages were still there.
I forced myself to type.
“Who are you?”
There was no answer.
I waited.
One minute.
Two minutes.
Then the read receipt appeared.
But there was no reply.
I grew even more anxious.
Without realizing it, my gaze shifted to the bedroom window. The white curtain moved slightly even though the window was closed.
I approached it.
Through the gap in the curtain, the school grounds looked dark. The corridor lights were still on, but some parts of the grounds were completely untouched by the light.
I watched the classroom building across from us.
Someone was standing there.
A female student.
Silent.
With her back to me.
I held my breath.
How could a student be outside the dorm this late at night?
I was about to call my friends when the figure slowly raised her hand.
She pointed toward the dorm building.
More precisely...
She pointed toward my window.
I immediately stepped back.
A few seconds later, the figure was gone.
I pulled the curtains tightly shut.
I didn’t sleep at all that night.
The next morning, I tried to convince myself that everything that had happened the night before was just a coincidence.
Maybe the messages had only been a joke.
Maybe the figure outside had just been a shadow.
Maybe I’d been thinking too much about what the upperclassman had said.
But when I got to class, that feeling returned.
Something was different.
My desk mate looked gloomy.
“What’s wrong?” I asked.
She looked at me for a moment before answering in a quiet voice.
“Did you hear about Rena?”
I shook my head.
“Who’s Rena?”
“The girl in the class next door.”
“What happened to her?”
She glanced to the right and left before leaning closer.
“She’s missing.”
I fell silent.
“Since when?”
“They say it was last night.”
I immediately remembered the messages I’d received.
The previous student.
I swallowed.
“Didn’t she go home?”
“No.”
Her answer suddenly made the space between us feel heavy.
“The teachers said she got permission to leave school yesterday afternoon. But...” She paused for a moment. “Her friend said Rena never left at all.”
I stared at her.
“Then what?”
“They say the last time she was seen... was near the old building.”
The old building.
I knew that place.
The building that had always been locked and never used.
I remembered the figure I’d seen the night before.
Suddenly, the bell rang.
All the students returned to their seats.
The teacher came in carrying several sheets of paper.
But before the lesson began, she wrote something on the board.
TODAY’S RULE:
I stared at the words with an uneasy feeling.
Then the teacher said,
“Starting today, no student is allowed to leave the classroom after the last bell.”
The classroom suddenly fell silent.
I looked at my desk mate.
She looked confused too.
The teacher continued,
“Anyone who breaks this rule will be punished.”
I raised my hand.
“Ma’am, why?”
The teacher stopped writing.
For several seconds, she looked at me.
Then she gave a faint smile.
“Because it’s a school rule.”
I lowered my hand.
But just as the teacher turned her back to me again, I heard the sound of a piece of paper being slipped beneath my desk.
I was startled.
Slowly, I picked it up.
There was no name.
Only a handwritten message.
“Don’t trust the teacher.”
I read the sentence over and over.
Beneath it was another sentence.
“The real rules only begin after the last bell.”
Before I could process what it meant, the school bell suddenly rang.
Even though the lesson had been going on for less than ten minutes.
Everyone fell silent.
The teacher froze at the front of the classroom too.
Then footsteps sounded from outside.
Slowly.
One step.
Then another.
Getting closer.
I looked toward the door.
The doorknob slowly turned.
And from behind the door came a woman’s whisper.
“Open up.”
I didn’t know who she was.
But I knew one thing.
It was exactly the same voice as the student I had seen the night before.