Horror story: subway elevator stopped at a floor that doesn't exist

I wasn't going to post this but here we go.

There are occasional reports that in certain subway transfer stations, elevators sometimes stop at an unmarked floor. A floor that doesn't exist for passengers.

Spring 2024. I was doing overnight maintenance checks at one of those massive transfer stations in the Seoul metro area. The job was simple, walk the facility after 1am when trains stop running, check for electrical issues, security stuff. Mostly boring. Mostly quiet.

Then one night I was alone, checking the big elevator in the Line 2-Line 7 transfer section. That elevator runs from B1 to B4. Anything below that is a restricted zone. I get in, hit B1 to go back up.

And then.

The panel lights up a button that was NOT there before.

-5.

I told myself it was a glitch. I genuinely told myself that. And then I pressed it anyway because apparently I have zero survival instincts.

The elevator moved. Quietly. The digital display clicked over to -5.

Doors opened.

Gray concrete. Dark lighting. Old signs on the walls. I squinted at one and could barely make out the text... something about a "trial operation section from the 1977 opening." Like a forgotten test corridor from when the station first launched.

Then the lights inside the elevator flickered.

And something moved in the mirror at the back.

I was alone. I was DEFINITELY alone when I got in. But in the mirror there were two people. Me, and a silhouette right behind me. Close. Like close close. Only showing its back.

I got out before the doors closed. Ran down the corridor as fast as I could.

Except the corridor coming back was not the same layout as the one I came from.

No exit. No stairs. Just... repeating ad panels and shuttered storefronts going on forever. And at the end of the corridor there was another mirror.

I wasn't in it.

Something else was. Standing where I should have been.

I hit the emergency alarm. Security found me.

They said I was on B3 when they found me.

I was on B5.

Afterward one of the security guys pulled me aside and goes, "you know there was an intern who went missing from that elevator once. Last signal they got from them was a call button ping. From the floor that doesn't exist."

There's a post going around social media now that says:

"Somewhere in Seoul, basement level 5, the unmarked floor. If you get there, do NOT let the doors close before you get out. Or you'll be the one left inside the mirror."

(I take the bus now.)