For several seconds, Aarav said nothing.
The tunnel air felt colder now, heavier somehow. The woman stood in front of him calmly, as if meeting strangers in abandoned underground tunnels was the most normal thing in the world.
Water dripped from the ceiling somewhere behind them.
Plink.
Plink.
Plink.
Aarav finally spoke.
"Alright… I followed the signal, I came to Tunnel 17, and now you're telling me there's another world under the city." He crossed his arms. "You'll have to explain that better."
The woman studied him quietly.
Then she turned and began walking deeper into the tunnel.
"Come with me."
Aarav didn't move.
"Or," she added without turning around, "you can go back upstairs and forget everything."
He hesitated.
But curiosity had already taken control.
"Wait," he said, catching up with her. "You still haven't told me your name."
She glanced sideways at him.
"Riya."
They continued walking.
The tunnel sloped downward for several minutes. The walls changed slowly—from rough concrete to older stone blocks that looked far older than the metro construction above.
Aarav noticed something strange.
Lights.
Small dim lamps were attached along the walls.
"Someone installed electricity down here," he said.
"Of course," Riya replied.
"Who?"
She didn't answer immediately.
Instead she stopped at a heavy steel door built directly into the stone tunnel.
Unlike the rusted entrance door above, this one looked new.
A keypad sat beside it.
Riya typed a code.
The door opened with a deep metallic sound.
Aarav stepped through—and froze.
The tunnel ended in a massive underground chamber.
And it was alive.
Generators hummed along the walls. Computers flickered on metal desks. Screens displayed maps, data streams, security cameras.
People moved between stations carrying equipment.
Some wore headphones.
Some studied blueprints.
Some were clearly armed.
Aarav stared in disbelief.
"What… is this place?"
Riya folded her arms.
"Welcome to Layer Zero."
He turned toward her.
"That doesn't explain anything."
She walked toward a large digital map displayed on the wall.
The same map Aarav had seen on his computer.
The city streets glowed faintly.
But beneath them…
The hidden tunnels formed a second network.
"This," she said, pointing at the underground map, "is the city people don't know exists."
Aarav stepped closer.
"These tunnels… who built them?"
"Different groups over many years," she said. "Old drainage systems, forgotten war shelters, unfinished metro routes."
She tapped the screen again.
"But ten years ago, someone connected them all."
"Who?"
Riya's expression hardened.
"A private organization called Helix."
The name meant nothing to Aarav.
"They discovered something beneath the city," she continued.
"Something valuable."
"Let me guess," Aarav said. "And you're trying to stop them."
"Not exactly."
Before he could ask another question, a man's voice spoke from behind them.
"Because we're the ones who stole it first."
Aarav turned.
A tall man in his thirties walked toward them.
Dark jacket.
Calm, confident expression.
He looked like someone used to being in charge.
Riya sighed slightly.
"You're awake."
The man smiled faintly.
"I've been awake the whole time."
He stopped in front of Aarav and studied him carefully.
"So this is the hacker you brought."
Aarav frowned.
"I'm not a hacker."
The man raised an eyebrow.
"You broke into three encrypted satellite servers last year."
Aarav blinked.
"How do you—"
The man extended his hand.
"Relax. If we wanted you arrested, it would've happened already."
Aarav slowly shook his hand.
"My name is Arjun."
Aarav tilted his head.
"Wait… you're running this place?"
Arjun chuckled slightly.
"No one runs Layer Zero."
Then his tone became more serious.
"But we do protect it."
Aarav looked around the underground chamber again.
"Protect it from who?"
Arjun's eyes darkened slightly.
"From the people who built the system we just stole."
He turned toward the giant digital map.
And zoomed the display outward.
A red symbol flashed beneath the center of the city.
"This," Arjun said quietly, "is what Helix is searching for."
Aarav leaned closer.
"What is it?"
Arjun looked at him directly.
"A machine."
"A machine?"
"Yes."
"A machine that was buried beneath this city seventy years ago."
Riya spoke softly beside him.
"And if Helix finds it first…"
Arjun finished the sentence.
"The world above us changes forever."
Silence filled the chamber.
Aarav stared at the glowing red mark on the map.
A hidden machine.
Buried for seventy years.
And somehow he had just become part of the race to find it.
Then Arjun added one final sentence.
"The problem is…"
Aarav looked up.
Arjun's expression had grown serious.
"Helix already knows we're here."
Across the room, one of the computer monitors suddenly flashed red.
An alarm began to sound.
A technician shouted.
"Multiple signals entering the tunnel network!"
Riya turned sharply.
"How many?"
"Unknown—"
The lights flickered.
Then the technician finished his sentence.
"…but they're getting closer."
Arjun exhaled slowly.
"Well," he said calmly, "that didn't take long."
Aarav looked between them.
"What's happening?"
Riya gave him a quick look.
"Your first night in the underground city."
She grabbed a small device from the table.
"Congratulations."
The alarm grew louder.
"They've come to kill us."