It arrived on a Sunday night, buried between retweets and a half-loaded recipe video.
A reply.
To a thread Aoi had long forgotten.
> Thread #0000431 — Kurokawa Incident \[SERIOUS ONLY]
> Posted by: DownLowFox
> "Anyone else still looking into Kurokawa? I used to go there. Sister disappeared before it shut down. If you have anything at all—old photos, archived files—DM me."
The post was dated two years ago.
She hadn't touched that account since. But the reply was new—only two hours old.
> anon\_781: "This her?"
Attached: a low-res photo. A Kurokawa student ID card. Slightly scratched.
Himura Ayaka. Class 2-B.
And the photo—blurry, but unmistakable. Her sister's tired, half-forced smile.
Aoi's phone nearly slipped from her hand.
---
The school had been locked down for three years now. "Health code violations," they said. Mold in the walls. Asbestos. Budget issues.
No one talked about the fire alarms going off every week before the shutdown. Or the emergency drills that ran longer than scheduled. Or the security cameras quietly being taken offline.
They especially didn't talk about the missing students.
---
Aoi hadn't planned anything. She didn't pack a flashlight or extra batteries. No journal, no compass, no little charm of Ayaka's to guide her back. Just her phone. And now, the image of the ID burned into her screen.
On Monday morning, she told her guardian she had club practice and didn't wait for a reply.
The train ride to Kurokawa was quiet. Overgrown grass blurred past the windows. The sky was the wrong kind of grey.
She walked from the station. Her old uniform shoes slipping slightly on the gravel.
The school gates weren't locked.
Just rusted open.
---
The entrance hall still smelled of cheap cleaner and stagnant water. Lights hummed weakly overhead, like they hadn't realized everyone had left.
The noticeboard still had faded fliers:
* Track and Field Tryouts – May 14
* New Cafeteria Menu
* Emergency Procedure Update: Drill Schedule TBD
And taped awkwardly near the top, curled at the edges:
"Let's All Do Our Part to Keep B-Wing Clean!"
Aoi stared at it for a long time.
B-Wing.
Ayaka's classroom had been in B-Wing.
---
She took a step forward. Her foot echoed too loudly.
Then, from somewhere far down the hallway—
A faint click.
Like a door unlocking.
Or locking again.