Nyra stood completely still.
The word echoed through the underground city.
Astra.
It wasn't spoken by Kian.
It wasn't Sera.
It wasn't Elias.
The voice had come from somewhere beyond the enormous doorway.
Nyra looked into the darkness.
“Who said that?”
No answer.
Kian stepped beside her.
“You heard it too, right?”
Nyra nodded.
“Yeah.”
Sera raised her flashlight and swept the beam across the city.
Nothing moved.
The underground city stretched farther than they could see.
Silver towers rose from the ground.
Bridges connected buildings high above them.
Strange lights floated through the air without wires.
The entire place looked as though it had been abandoned only yesterday.
Yet everything was covered in dust.
Thousands of years of dust.
Kian slowly lowered his flashlight.
“How is any of this still working?”
Nyra walked toward the nearest building.
“I don't know.”
She placed her hand against its wall.
The moment her fingers touched the surface, the entire building illuminated.
A wave of silver light travelled across the city.
One tower after another awakened.
Then another.
Then another.
Within seconds, the entire underground world was glowing.
Sera stepped backward.
“Nyra, take your hand off it.”
Nyra did.
The lights remained.
A low humming sound filled the air.
Elias stared at the city.
“I've never seen this.”
Nyra looked at him.
“You knew this place existed.”
“I knew there were stories.”
“That's not what I asked.”
Elias remained silent.
Nyra walked toward him.
“You knew.”
He sighed.
“We found references to it.”
“When?”
“Years ago.”
“Why didn't you tell me?”
“Because we couldn't find the entrance.”
Nyra looked around.
“And now?”
Elias looked directly at her.
“Now the city has recognized you.”
Kian frowned.
“Recognized her as what?”
Elias didn't answer.
A sound suddenly echoed through the city.
A deep metallic tone.
Once.
Twice.
Three times.
The towers began changing.
Their smooth surfaces opened.
Inside each tower were enormous circular chambers.
Nyra stared.
“Those aren't buildings.”
“What are they?” Kian asked.
Nyra stepped closer.
“Machines.”
Sera looked toward the sky of the underground city.
“Machines for what?”
Nyra didn't know.
But she could feel the answer.
The same strange pressure she had experienced beneath the railway station returned.
Something was communicating with her.
Not through words.
Through images.
She closed her eyes.
And suddenly she wasn't standing in the underground city anymore.
She was somewhere else.
A vast room surrounded her.
Thousands of people stood around a massive machine.
They weren't wearing modern clothes.
They looked ancient.
But the technology around them was impossible.
At the center of the room stood a little girl.
Nyra.
Three years old.
Again.
But this memory was different.
She wasn't frightened.
She was smiling.
An elderly woman knelt in front of her.
The woman placed a hand on Nyra's shoulder.
“You have to remember.”
Little Nyra looked up.
“Remember what?”
“Who you were.”
The scene changed.
A massive city appeared.
Then fire.
Then darkness.
Then a silver doorway.
Nyra saw thousands of people running toward it.
The Architects were there.
But they weren't attacking.
They were trying to escape.
Then she saw something else.
A black shape moving behind them.
The Hollow.
The vision ended.
Nyra opened her eyes.
She was back in the underground city.
Kian was standing in front of her.
“Nyra?”
She looked at him.
“I saw them.”
“Who?”
“The first humans.”
Sera approached.
“What did you see?”
Nyra looked toward the towers.
“They weren't running from the Architects.”
Elias stepped closer.
“Then what were they running from?”
Nyra looked at him.
“The Hollow.”
Elias went silent.
Nyra noticed.
“You knew.”
“No.”
“You did.”
“I knew the name.”
“But you didn't tell me.”
“Because I didn't know if it was real.”
Nyra shook her head.
“You've spent your entire life hiding things from me.”
Elias looked hurt.
“I spent my life trying to keep you alive.”
Nyra's expression hardened.
“And how's that going?”
Before Elias could respond, the city suddenly shook.
A deep rumble travelled beneath their feet.
Kian grabbed the nearest railing.
“What now?”
Nyra looked toward the center of the city.
A tower was rising.
It pushed through the underground ceiling.
Stone cracked around it.
The tower continued upward until it disappeared into darkness.
Then a beam of silver light shot from its peak.
Straight through the Earth.
Nyra looked at her laptop.
Every screen displayed the same coordinates.
She recognized them.
Kampala.
But the coordinates weren't above ground.
They were beneath the city.
Far beneath.
Nyra whispered:
“The transmitter.”
Sera looked at her.
“What?”
“The original transmitter.”
She pointed at the coordinates.
“It's here.”
Elias stared at the screen.
“No.”
Nyra looked at him.
“You said it was beneath the planet.”
“I was wrong.”
The city suddenly spoke.
Not through speakers.
Through every wall.
Every tower.
Every machine.
One word echoed across the underground world.
ASTRA.
Nyra felt the strange pressure return.
This time, the voice spoke directly into her mind.
WELCOME BACK.
Nyra's eyes widened.
She whispered:
“I've been here before.”
Kian looked at her.
“How?”
Nyra stared at the enormous tower.
“I don't know.”
The tower opened.
A staircase appeared inside.
It descended deeper into the Earth.
Nyra looked at Sera.
Sera shook her head.
“Absolutely not.”
Nyra smiled faintly.
“You know I'm going.”
“I know.”
Kian sighed.
“Then I guess we're going too.”
Elias didn't move.
Nyra looked at him.
“You coming?”
He stared into the staircase.
For the first time since they'd met, Elias looked genuinely afraid.
“No.”
Nyra frowned.
“Why?”
Elias whispered:
“Because I know what's down there.”
The city lights suddenly changed.
A message appeared across every tower.
THE LAST KEY HAS RETURNED.
Then another.
THE MEMORY CHAMBER IS OPEN.
Nyra looked at Elias.
“What memory?”
Elias closed his eyes.
“The one I prayed you'd never recover.”
Nyra stepped toward the staircase.
“Then that's exactly the memory I need.”
And she began walking downward.