The door beneath the observatory had no handle.

No hinges.

No lock.

It simply waited in the floor like a dark wound that had been hidden for centuries.

Mira stood above it with the blue sphere trembling in her hand.

For several seconds, she considered walking away.

That would have been the sensible thing.

Go home.

Forget the strange voice.

Forget the boy named Eren.

Forget the impossible image of herself sleeping inside a glass chamber forty years in the future.

But Mira had never been good at leaving mysteries alone.

She placed the blue sphere against the center of the door.

A soft chime echoed through the observatory.

Then the floor disappeared.

Mira gasped.

She dropped through darkness.

For a moment, she felt weightless.

Then—

THUD.

She landed on something soft.

Dust filled the air.

Mira coughed and pushed herself upright.

Her flashlight flickered on.

She was inside a tunnel.

The walls were covered with enormous silver cables. Some were broken. Others pulsed with faint blue light.

The air smelled old.

Not like the clean artificial atmosphere of Nova City.

It smelled like rain.

Like earth.

Like a world that had been forgotten.

Mira looked upward.

The entrance above her had vanished.

“Great,” she whispered.

The blue sphere floated beside her.

Its light illuminated a narrow path ahead.

Mira followed it.

Every few steps, strange symbols appeared on the walls.

Some looked like letters.

Others resembled stars.

Then she noticed something that made her stop.

A sentence had been carved into the metal.

THE CITY WAS NEVER BUILT ABOVE US.

Mira touched the words.

A second line appeared beneath them.

IT WAS BUILT ON TOP OF US.

She stepped backward.

“What does that mean?”

The sphere pulsed.

A holographic map appeared in the air.

It showed Nova City floating above the clouds.

Then the image slowly moved downward.

Beneath the beautiful towers was another city.

Then another.

And another.

Seven layers.

Seven hidden cities.

Mira stared at the map.

“Seven cities beneath Nova City?”

A voice answered from behind her.

“Not seven.”

Mira spun around.

Her heart nearly stopped.

A boy stood in the tunnel.

Black jacket.

Messy dark hair.

Pale blue eyes.

The same face she had seen inside the sphere.

Mira raised the metal pipe she had picked up from the floor.

“Stay back.”

The boy lifted both hands.

“Easy.”

“You’re Eren.”

He smiled faintly.

“Not exactly.”

Mira tightened her grip.

“You said you were forty years in the future.”

“I am.”

“Then how are you here?”

Eren looked at the blue sphere.

“I’m not.”

Mira frowned.

“What?”

“You’re not seeing me.”

He stepped closer.

Mira swung the pipe.

It passed directly through him.

She froze.

Eren looked almost amused.

“I’m a memory.”

Mira lowered the pipe.

“A memory?”

“A recording. A message. Something your time can understand.”

“Then where are you really?”

Eren’s expression changed.

“Somewhere that doesn’t exist yet.”

The tunnel shook.

Dust fell from the ceiling.

Eren looked toward the darkness behind him.

“We need to move.”

Mira followed him.

“Move where?”

“Down.”

“How far?”

Eren looked at her.

“Until the city stops pretending.”

They continued through the tunnel.

The deeper they went, the stranger everything became.

Old advertisements appeared on the walls.

WELCOME TO EARTH 2191.

WELCOME TO THE NEW HUMAN ERA.

WELCOME TO A WORLD WITHOUT SLEEP.

Mira stopped at the last message.

“A world without sleep?”

Eren looked at the words.

“That was the beginning.”

“The beginning of what?”

“The Dream Program.”

Mira waited.

Eren continued.

“After the solar wars, humanity needed a way to rebuild civilization. Resources were limited. Cities were destroyed. Millions were homeless.”

He paused.

“So scientists created a system that allowed humans to live inside controlled dreams while machines rebuilt the planet.”

Mira stared at him.

“People were dreaming?”

“Yes.”

“For how long?”

“Originally?”

“A few months.”

“And later?”

Eren didn’t answer.

Mira’s voice became quieter.

“How long?”

“Forever.”

The tunnel seemed to become colder.

Mira looked at the blue lights.

“So Nova City…”

“Isn’t real.”

Mira shook her head.

“No. I live there.”

“I know.”

“My apartment is real.”

“It feels real.”

“My school. The trains. The parks…”

“All generated.”

Mira stepped away.

“You’re lying.”

“I wish I was.”

She looked at the walls.

At the cables.

At the ancient machinery.

Suddenly, she remembered something.

Every morning, her bedroom window showed the same sunrise.

Every evening, the same golden clouds appeared.

Every night, the same three stars were visible through the Veil.

She had always thought it was beautiful.

Now it felt wrong.

“Why don’t people know?”

“Because they aren’t supposed to.”

“Who controls the dreams?”

Eren’s eyes darkened.

“The city.”

Mira laughed bitterly.

“Cities don’t control people.”

“This one does.”

A sound echoed through the tunnel.

Footsteps.

Slow.

Heavy.

Mira turned.

Nothing.

Then two blue eyes appeared far away.

Eren’s expression changed instantly.

“Run.”

Mira didn’t argue.

They sprinted through the tunnel.

Behind them came a metallic roar.

Mira looked back.

Something crawled along the ceiling.

It was tall and impossibly thin.

Its body was made of black metal.

Its face was smooth.

No eyes.

No mouth.

Only a glowing blue symbol across its forehead.

Mira ran faster.

“What is that?”

“A Dreamkeeper.”

“Why is it chasing me?”

“Because you woke up.”

The tunnel ended.

Mira almost crashed into a huge metal wall.

Eren pointed toward a small door.

“Open it!”

“How?”

“Think about home.”

Mira stared at him.

“What?”

“Think about the place you believe is home.”

Mira closed her eyes.

She imagined her apartment.

Her bed.

Her window.

Her mother’s old photograph.

The door opened.

Mira fell through.

Eren followed.

The door slammed shut behind them.

The Dreamkeeper struck it.

BOOM.

The entire room shook.

Mira backed away.

Then she looked around.

She couldn’t speak.

They were standing inside an enormous underground city.

Buildings rose from the darkness.

Empty trains floated between towers.

Trees grew beneath artificial moons.

Thousands of windows glowed faintly.

But there were no people.

Only statues.

Millions of them.

Mira walked toward the nearest one.

It was a woman.

She looked asleep.

Her eyes were closed.

Her hands rested peacefully against her chest.

Mira touched the statue.

It was warm.

“That’s not a statue.”

Eren shook his head.

“No.”

Mira stared at him.

“Then what is it?”

“Someone dreaming.”

She looked across the enormous city.

There were thousands.

Then millions.

People everywhere.

Sleeping while their minds lived inside Nova City.

Mira’s breathing became unsteady.

“Where are their bodies?”

Eren pointed toward the walls.

Behind the glass were endless rows of chambers.

Each chamber contained a sleeping human.

Children.

Adults.

Old people.

Families.

People who had been asleep for decades.

Mira saw a little girl holding a stuffed rabbit.

She looked about six.

“How long has she been here?”

Eren didn’t answer.

Mira looked at the chamber.

A small screen displayed:

SLEEP CYCLE: 63 YEARS

Mira covered her mouth.

“That’s impossible.”

“It’s normal here.”

She moved through the chambers.

Everywhere she looked, she saw another sleeping person.

Then she saw something familiar.

A woman.

Dark brown hair.

A small silver necklace.

Mira stopped breathing.

“Mum?”

The world seemed to disappear.

She ran toward the glass.

Inside the chamber was her mother.

Exactly as Mira remembered her.

Young.

Peaceful.

Alive.

Mira pressed both hands against the glass.

“Mum…”

Her eyes filled with tears.

“You’re alive.”

Eren stood behind her.

“She never died.”

Mira turned toward him.

“Why did she leave me?”

“She didn’t.”

“Then why didn’t she come back?”

“She tried.”

Mira shook her head.

“No.”

“She discovered the truth.”

“What truth?”

Eren looked toward the sleeping woman.

“Your mother wasn’t the creator of the Dream Program.”

Mira waited.

“She was its prisoner.”

A soft sound came from the chamber.

Mira turned.

Her mother’s eyes opened.

For a moment, she simply stared.

Then her lips moved.

Mira couldn’t hear her.

She pressed closer to the glass.

Her mother whispered something.

Mira’s eyes widened.

“What did she say?”

Eren looked terrified.

“She said…”

He stopped.

“What?”

“She said your name.”

Mira’s mother placed one hand against the glass.

Then the entire underground city turned blue.

Every sleeping person opened their eyes.

At once.

Mira stepped backward.

Thousands of faces turned toward her.

Then millions.

And from every chamber came the same whisper.

“Mira.”

The blue sphere in her hand cracked.

A strange light poured from it.

Eren stared at the sphere.

“No…”

Mira looked at him.

“What?”

He backed away.

“You weren’t supposed to wake up yet.”

“Wake up from what?”

Eren’s voice trembled.

“Your dream.”

The underground city disappeared.

Mira opened her eyes.

She was lying inside a glass chamber.

Cold metal surrounded her.

Machines hummed above her head.

Her body felt weak.

Beyond the glass stood a woman.

Her mother.

Alive.

And beside her stood Eren.

But this time…

he wasn’t a hologram.

He was real.

Mira stared at them.

Her mother touched the glass.

“I’m sorry.”

Mira couldn’t move.

“Why?”

Her mother looked toward Eren.

Then toward the ceiling.

“Because the world you remember…”

The lights went out.

A gigantic heartbeat echoed through the underground city.

THUMP.

THUMP.

THUMP.

Her mother whispered:

“…isn’t Earth.”

And somewhere beneath them, something enormous began to wake.