Don't open a door that doesn't exist in your house.
An's house had only three doors. One front door. One bedroom door. One bathroom door.
She was certain of that. Until Saturday morning.
An woke up and saw a white door at the end of the hallway. She stood in front of it for a long time.
There was no doorknob. No lock. No sign that it had ever existed.
An thought she was dreaming. She went back inside, drank a glass of water, then came back out.
The door was still there.
A small piece of paper was stuck to it.
DON'T OPEN.
An laughed. Someone was probably playing a prank on her.
She called her landlord. "Hey, there's an extra door in my house."
The other end of the line was silent for a long time.
"Where are you standing?"
"At the end of the hallway."
"An, listen to me."
Her landlord's voice suddenly turned serious.
"Don't touch it."
"Why?"
"Because that house..."
"...doesn't have a hallway."
The call ended immediately.
An looked around.
Only then did she realize something.
The hallway in front of her was much longer than usual.
The bedroom door had been only a few steps from the living room. Now... it was nearly twenty meters away.
An began to feel a chill.
She turned around.
The living room behind her had disappeared.
In its place was another long hallway, exactly the same as this one.
And at the end of the hallway... there was another white door.
An ran toward it.
The farther she ran, the farther away it seemed.
Then her phone vibrated.
A text from her landlord:
"If you've seen the fourth door, don't try to find your way out."
A second message arrived right after it.
"Remember to check what number is on the door."
An looked back.
A number had appeared on the door in front of her.
4.
Suddenly, she understood.
This wasn't the fourth door.
It was Room 4.
And she was standing... inside a place that didn't exist.
An didn't dare open the door.
She sat down on the floor and waited.
One hour. Two hours. Three hours.
By the time it got dark, a person's voice rang out from the other side of the door.
"An?"
It was her mother's voice.
"Open the door for Mom."
An closed her eyes.
Her mother was living in another city.
"An..."
The voice outside began to cry.
"Don't you remember me?"
An remained silent.
After a while, the voice disappeared.
The space grew quiet.
Then she heard footsteps moving farther and farther away.
An let out a sigh of relief.
At that exact moment, her phone lit up.
One final message from her landlord:
"Good. You did the right thing."
An had barely finished reading it when the next message appeared.
"But I'm sorry..."
"I thought that door only appeared in my house."
An looked up.
At the end of the hallway, another door slowly appeared.
Then another.
Then another.
They all looked exactly the same.
On every door... there was a number.
1. 2. 3. 4. 5. ...
An looked all the way down the hallway.
There were ninety-nine doors in total.
The final door had no number.
It only had one line of text:
"This door is for the person reading this."
An stared at the words.
And for the first time since the door appeared... she heard knocking.
Not from in front of her.
But from... behind her.
Note in the 99 Forbidden Rules notebook
If one day an extra door appears in your house...
Don't open it.
Don't try to find out where it leads.
And most importantly...
Don't count how many doors there are.
Because some doors only appear... after you know they exist.