The traveller had become careful about knocking.
In another city, knocking was simple.
You came to a door.
You knocked.
Someone opened it.
Or did not.
The world remained more or less where it had been.
In this city, she had learned, knocking could be a dangerous activity.
A knock might be answered by a voice from a room that did not yet exist.
A door might disappear after it had been opened.
A locked door might ask her why she wanted it opened.
An empty room might prove to contain more than she had expected.
So when the traveller heard a knocking sound one morning, she did not immediately follow it.
She was walking through the southern quarter.
The streets there were unfamiliar.
They rose and fell without apparent reason, passing beneath arches and between high walls.
The knocking came from somewhere nearby.
Three slow knocks.
Then silence.
Three more.
The traveller stopped.
There was no door.
She looked along the street.
Blank walls.
Shuttered windows.
A narrow staircase.
No door.
The knocking came again.
Three times.
She walked towards the sound.
It seemed to come from the wall beside her.
She placed her hand against the stone.
Nothing.
She leaned closer.
Three knocks.
From the other side.
The traveller stepped back.
“Who is there?”
No answer.
She looked up and down the street.
Still no door.
She felt foolish.
Then she remembered the child with the wooden box.
Not yet a window.
She raised her hand.
And knocked.
Once.
Twice.
Three times.
Nothing happened.
She waited.
Then she knocked again.
The wall remained a wall.
The traveller smiled.
Perhaps she had finally found something in the city that behaved normally.
She turned to leave.
Behind her came three knocks.
She stopped.
Slowly, she turned back.
There was a line in the wall.
It was faint.
So faint that she might not have noticed it if she had not been looking.
She stepped closer.
The line was vertical.
A second appeared beside it.
Then a horizontal line.
A rectangle.
The traveller stood perfectly still.
A door was beginning to appear.
It did not emerge suddenly.
It seemed to gather itself from the wall.
The stone darkened.
The outline deepened.
Wood appeared where there had been stone.
An iron handle formed.
The traveller looked at it.
Then, without thinking, she knocked again.
The handle moved.
The door opened.
There was nothing behind it.
Not darkness.
Not an empty room.
Not even a wall.
The doorway opened onto the street.
The same street.
The traveller looked through.
On the other side was the city she had just been walking through.
Except that it was not the same.
The buildings stood differently.
A balcony had appeared above a shop.
The staircase had become wider.
The wall opposite contained three doors.
She looked behind her.
The street she had come from.
She looked through the door.
Another version of it.
She stepped across.
The door closed.
She turned around.
The door was gone.
The wall behind her was covered in ivy.
She had never seen the ivy before.
The traveller stood in the middle of the street.
A woman was watching from a doorway.
“Did you knock?” she asked.
“Yes.”
The woman nodded.
“That explains it.”
“What?”
“The door.”
The traveller looked at the wall.
“I thought the door appeared because I knocked.”
“Perhaps.”
“Didn't it?”
The woman shrugged.
“You knocked because it appeared.”
“No.”
“I heard knocking.”
“Yes.”
“Then I found the wall.”
“Yes.”
“Then I knocked.”
“Yes.”
“And then the door appeared.”
The woman smiled.
“That is one order in which to tell the story.”
The traveller felt a familiar irritation.
“There are not many orders. That is what happened.”
“Is it?”
“Yes.”
The woman stepped outside.
“Why did you follow the sound?”
“Because I heard knocking.”
“Why did you hear it?”
The traveller hesitated.
“I don't know.”
“Perhaps because you were listening.”
The traveller looked towards the wall.
“So?”
“So perhaps the door began before you knocked.”
“Then why wasn't it there?”
“Perhaps it was not yet a door.”
The traveller folded her arms.
“You're going to tell me that knocking made it one.”
The woman considered this.
“No.”
The traveller looked at her.
“No?”
“No.”
“Then what did?”
The woman pointed at the street.
“Everything.”
The traveller laughed.
“That is not an answer.”
“It is a large city.”
The woman began walking.
After a moment, the traveller followed.
They passed a baker carrying trays of bread.
The traveller recognised him.
“The corridor is still there?” she asked.
“Sometimes,” said the woman.
“What does that mean?”
“Sometimes the library and bakery need one another.”
“And sometimes they don't?”
“Yes.”
“So the corridor disappears.”
“Sometimes.”
The traveller thought about the door.
The knocking.
The wall.
The sound.
The expectation.
“Did I make the door appear?”
The woman continued walking.
“What do you think?”
“I think I participated in its appearing.”
The woman stopped.
The traveller realised she had spoken before thinking.
The woman smiled.
“That is closer.”
“Closer to what?”
“To the difficulty.”
They walked beneath an arch.
Beyond it was a square the traveller had never seen.
At its centre stood a dry fountain.
Around the edge were six doors.
All were closed.
The traveller looked at them.
“Which one should I knock on?”
“Why knock?”
“To see what happens.”
The woman shook her head.
“Then you have learned nothing.”
The traveller looked again at the doors.
“What should I do?”
“Wait.”
“For what?”
“Until you have a reason.”
She sat on the edge of the fountain.
The traveller remained standing.
For several minutes nothing happened.
A man crossed the square carrying a bundle of cloth.
He stopped at one of the doors.
He knocked.
The door opened.
He went inside.
A child emerged from another door.
The child did not knock.
She simply opened it.
An old woman approached a third door.
She stood before it for some time.
Then turned away.
The traveller watched.
“Why didn't she knock?”
“Perhaps there was no reason to.”
“But perhaps there was something behind it.”
The woman nodded.
“Perhaps.”
“So she might have missed a possibility.”
“Perhaps.”
The traveller frowned.
“That seems important.”
“It is.”
“Then why didn't she try?”
The woman looked at her.
“Because not every possibility becomes possible by being tried.”
The traveller sat down.
She thought of the locked door.
The key that did not exist.
The room that had not yet become.
The corridor that appeared when the library and bakery acquired somewhere to go.
The empty room.
The city was not full of possibilities waiting to be discovered.
Possibilities seemed to arise within histories.
Within needs.
Within relations.
Within questions.
And perhaps within actions.
She looked at the woman.
“So if I had not knocked, the door might never have appeared.”
“Yes.”
“But if I had knocked on every wall, I would not have created every possible door.”
“No.”
“Then knocking isn't enough.”
“No.”
“What else is required?”
The woman looked around the square.
“Listen.”
The traveller listened.
At first she heard nothing unusual.
Footsteps.
Voices.
A cart in the distance.
A shutter closing.
Then she heard something else.
A faint knocking.
She stood.
“Where?”
The sound came again.
Three knocks.
She walked towards the northern wall.
Nothing.
Three knocks.
She placed her hand against the stone.
This time she did not knock.
She waited.
Three knocks.
From the other side.
“What are you waiting for?” asked the woman.
The traveller did not answer.
She was listening.
The knocking came again.
She began to notice its rhythm.
Not three equal knocks.
The first was slow.
The second quicker.
The third almost immediately after.
She looked at the wall.
There was a crack near the ground.
She knelt.
The crack ran horizontally for several feet.
A pipe?
No.
A seam?
Perhaps.
The knocking came again.
She followed the sound along the wall.
At the far end was a small patch of darker stone.
She touched it.
Warm.
She removed her hand.
The knocking stopped.
She waited.
Nothing.
Then, from somewhere behind her, came another sound.
A door opening.
She turned.
One of the six doors in the square was open.
The woman was standing beside it.
“Did you do that?”
“No.”
The woman pointed towards the wall.
“You did.”
The traveller looked between the wall and the open door.
“I didn't touch it.”
“You listened.”
“That isn't doing anything.”
“Isn't it?”
The traveller walked towards the open door.
Beyond it was a small workshop.
A man sat at a table repairing clocks.
She had never seen him before.
He looked up.
“You're late.”
The traveller laughed.
“I didn't know I was coming.”
“Few people do.”
She entered.
The room was crowded with clocks.
Large clocks.
Small clocks.
Broken clocks.
Clocks with no hands.
Clocks that ticked too quickly.
Clocks that did not move at all.
On the table was an unfinished clock.
“What are you making?” she asked.
“A door.”
She looked at him.
“A clock.”
“Is it?”
He smiled.
The traveller had learned not to answer quickly.
She walked around the workshop.
Every clock showed a different time.
“Which one is correct?”
The man looked around.
“Correct for what?”
She smiled.
The city was becoming predictable again.
She stopped beside the unfinished clock.
It had no face.
No hands.
Only an empty circular frame.
“Why did the door open?”
The man continued working.
“Which door?”
“The one outside.”
“You knocked.”
“I didn't.”
“You listened.”
“That isn't the same thing.”
“No.”
“Then why did it open?”
He looked up.
“Because you heard it.”
The traveller was silent.
The answer irritated her.
She had heard many things in the city that had not opened doors.
The man seemed to understand.
“You think participation means control.”
She looked at him.
“I didn't say that.”
“No.”
He placed a small piece of metal inside the clock.
“But you keep asking what you did.”
The traveller looked through the doorway.
The square was still there.
The woman sat beside the dry fountain.
The wall remained blank.
“I don't know what I did.”
The man nodded.
“Better.”
“What does that mean?”
“It means you may be ready to notice.”
“To notice what?”
“That the city does not wait for you.”
The traveller looked at him.
“But it changes when I act.”
“Yes.”
“So I participate.”
“Yes.”
“But I do not control what happens.”
“No.”
She thought for a moment.
“Then what am I?”
The clockmaker returned to his work.
“A condition.”
The traveller frowned.
“Of what?”
He smiled.
“You'll see.”
She left the workshop.
Outside, the woman was waiting.
The traveller walked beside her.
Neither spoke for a while.
At the edge of the square, they came to a wall.
There was no door.
The traveller stopped.
The woman looked at her.
“Are you going to knock?”
The traveller considered.
“No.”
“Why not?”
“Because I don't hear anything.”
The woman smiled.
They walked on.
After a few steps, the traveller heard a sound behind her.
One knock.
Then another.
Then a third.
She turned.
The wall was still blank.
She waited.
Nothing.
She smiled.
“Perhaps it isn't a door.”
“Perhaps.”
They continued walking.
The traveller did not knock.
Not because she had learned that doors should be left alone.
And not because she feared what might appear.
She simply understood now that a possibility was not something she could summon by demanding it.
Nor was it something waiting obediently behind every unopened wall.
A possibility emerged when the world became capable of being otherwise.
Sometimes a knock was part of that becoming.
Sometimes a question.
Sometimes a journey.
Sometimes nothing she could identify at all.
The traveller looked down the street.
Ahead of them, the city opened into mist.
She could see no door.
No passage.
No destination.
But for the first time, she did not think of the mist as hiding what was already there.
She wondered what might become possible because she had walked towards it.
Behind her, somewhere in the city, someone knocked.
This time, she did not turn around.
A moment later, a door opened.