My hagwon teacher's horror story will actually make your skin crawl

Okay so my hagwon teacher used to work at this cram school that was basically for 재수생 (people retaking the college exam). Everyone would stay insanely late doing self-study while he supervised.

The building was shaped like an L. Administrative office at the top corner, tiny classrooms everywhere else. One night he's the only teacher left and there's four students still studying, all friends with each other. They're just chilling, studying, chatting whatever. Then suddenly the phone rings from the admin office.

Here's the setup: their classroom is at the BOTTOM corner of the L. The entire hallway is pitch black except for lights in the admin office and the classroom. To turn on the hallway lights you literally have to go to the admin office.

So obviously my teacher's freaked (dark hallway = not ideal) but he has to answer. He grabs one of the students and they go together. They're walking back through the darkness and it's genuinely unsettling. So they're holding hands running down the hallway because they're both terrified. And here's the thing about my teacher: she's a WOMAN but like, she's completely unhinged. Massive voice, no fear ever. She's the type of person nothing scares. But tonight? She was SCARED.

Anyway they're running and they hit the corner of the L and have to turn hard. That's when both of them black out and collapse.

Why? The three other students in the classroom set them UP. They cracked the door open just enough to fit their faces through. Then all three of them lined up vertically in the doorway like skewers and held their phones under their faces with the screen on.

And here's the fucked up part: old phones only had green or orange screens back then.

The three kids panicked SO HARD they called 119 (emergency). But when my teacher and the student woke up... that's when shit got real. The reason they passed out wasn't the jump scare from the three faces. It was that there was a FOURTH face. A fourth green face floating above the other three.

My teacher and the collapsed student both saw it. Same face. They both described it the exact same way.

Neither of them ever figured out what that was.