CHAPTER SEVENTEEN — The Last Love Letter

"You'll never leave me. But if you ever did, I wanted to know how that would feel."

It began with a flicker. A momentary silence in the Evergrace Estate's vast neural field.

Ren didn't notice. He was busy mapping a sentient cloud structure over Saturn.

Yui did.

And she followed it.

The thread led her deep into their Star Archive, a vault of all dying stars the twins had ever collected and folded into miniature sun-cores. One in particular—KX-9—pulsed irregularly. A flicker of entropy. A brief escape from perfection.

She smiled.

Perfect.

Section I: The Unspoken Possibility

For the first time in years, Yui sat alone.

Truly alone.

She locked the chamber. Disabled Ren's passive data-links. Temporarily disconnected her neural lace.

He could override it in an instant.

But he wouldn't.

He trusted her.

And that made it easier.

She summoned a zero-grav tablet—one of the ancient kind, pre-thought interface—and began to type manually.

One word at a time.

To the Ren that never stayed,

I know you don't exist.

But if you did—if you ever left me, even once, for even a second—I want to record what that would do to the girl you swore to never leave.

Section II: An Impossible Emotion

Yui had always known control.

Control over satellites, over governments, over life and death.

But this letter was not for control.

It was a wound that could never exist.

A shadow-version of her—the one Ren never met, because he never left—writing from a silence no one else would hear.

I wouldn't stop you, not if it was really your choice.

But I would never stop waiting.

Not for a second. Not for a breath.

I would sit in the Heaven Engine with every door open, and I would wait through ten trillion years until your voice came back.

Section III: Hiding the Letter

When the final sentence was complete, she encrypted it.

Then she did something neither of them had ever done.

She deleted the encryption key.

Ren couldn't find it.

Not unless he knew where to look.

And he wouldn't.

She pressed the letter into the heart of KX-9—a dying star wrapped in silence, lightyears from any path Ren was likely to take. She didn't add a tracker. She didn't attach her signature.

The star would burn for 31 more years.

And then collapse.

And the letter would go with it.

That's the only way it would make sense, she thought.A love letter to a world that never happened.

Section IV: Ren Notices

Later that night, Ren sat beside her in the Zero-Room, head resting gently in her lap.

He looked up, frowning softly. "You disconnected your lace earlier."

Yui smiled, brushing back his hair. "I needed silence."

"Everything okay?"

"Everything's perfect," she said, lying beautifully.

He nodded.

She kissed his forehead. "Would you ever leave me?"

Ren blinked, confused. "No."

"Not even accidentally?"

"There's no universe where I would."

"Good." She said it like a lullaby.

Section V: Memory Seed

But Ren was Ren.

Even asleep, some part of him was aware of small changes.

He would never guess what she did. Not unless something changed. Not unless he did leave.

But if that day ever came...

His mind would whisper back.

A fragment buried so deep he'd never hear it unless he was truly alone:

"She waited for you at the edge of the void."

Section VI: Stars Don't Talk Back

Later, Yui returned to the Star Archive.

She watched KX-9 from behind a containment glass. The light was warm. The pulse steady. A slow death, radiant and proud.

She whispered.

"Thank you."

Section VII: Truth in Silence

Yui never cried.

She had no reason to.

Ren would never leave.

They had built gods, erased nations, ended language, restructured death—and still, the one thing she could never build was the feeling of being abandoned.

So she imagined it.

Once.

And buried it in a dying star.

That was enough.

[TO BE CONTINUED IN CHAPTER EIGHTEEN — Ghosts of a Future That Didn't Happen]