The building must be at least ten stories tall. You must be alone. The time does not matter, but night is better — not for atmosphere, but because there are fewer witnesses, and witnesses complicate things in ways that are difficult to explain afterward.
Step into the elevator on the first floor. The doors must close with only you inside. If anyone else is in the elevator, abandon the attempt. Leave the building. Come back another night.
The sequence is as follows: Fourth floor. Second floor. Sixth floor. Second floor. Tenth floor. Fifth floor.
On the fifth floor, a woman will board the elevator.
She will stand beside you. She will say nothing. She will look at you, or she will look at the doors, or she will look at something you cannot see — it does not matter what she looks at. What matters is this: do not look at her. Do not speak to her. Do not acknowledge her in any way. She is not a woman.
If you speak to her, the ritual ends. Some accounts say it ends badly. There is a girl who tried this in a building in Busan. Her name is not recorded in any of the accounts I've found, but her fate is. She spoke to the woman on the fifth floor. They found her on the rooftop fourteen hours later. The police report described her state as "consistent with extreme fear and exposure." She had no memory of anything after the elevator doors opened.
If you survive the fifth floor — if the woman boards and you stare at the doors and you say nothing and you feel her standing beside you and you do not look — press the button for the first floor.
If the elevator goes up instead of down, you are going to the other world.
The other world looks like this place. It looks exactly like this place. The lobby you arrive in will be identical to the one you left. The building will be identical. The street outside, if you look through the glass doors, will be familiar. But there will be no one in it. No cars. No pigeons. No movement of any kind. The lights will all be on — every window in every building, every streetlamp — but there will be no one to have turned them on.
The only light that will be different is a red one, visible far away, at the end of a street you may not have noticed before.
Do not go toward the red light.
Some people have. The accounts end there, which is the most information an ending can provide.
To return, you must return to the elevator. You must press one, and only one, and you must not press any other button and you must not stop on any other floor, and you must not get out if the doors open unexpectedly. If they open, keep looking forward. Press close. Press one again. The woman will be there for the return journey or she will not — the accounts differ on this point, and I cannot tell you what it means either way.
If the elevator descends and the doors open on the first floor, you are home. You will know it is the first floor of this world because there will be people, and noise, and the ordinary texture of existence that you did not appreciate until it was absent.
You may feel wrong for days afterward. A persistent sense of slight displacement. The certainty that something is slightly behind you. A feeling that the lights in your apartment are brighter than they should be, or dimmer, depending on the account.
I have collected seventeen first-person accounts of this ritual. Eleven claim successful return. Two claim the woman was gone on the return journey. Three accounts stop mid-sentence, the authors apparently choosing not to finish them. One account ends with a single line, typed in lowercase, with no punctuation:
"don't do this i'm still there"
I do not know what to do with that.
The ritual is documented. The sequence is documented. What is not documented is why the building on the corner of Sejong-daero has had five noise complaints and one missing persons report in the last two years, all connected to its elevators, all filed on nights when the building was supposed to be empty.