Ren arrived at school five minutes earlier than usual.
That alone was enough to make the world uneasy.
The hallway smelled the same-cleaning chemicals mixed with cheap floor wax-but something subtle felt off. Like a painting that had been rehung one centimeter lower than before.
He scanned his surroundings without turning his head.
Three students laughing by the lockers.
A teacher rushing with coffee.
The security camera above the stairwell.
"...There," Ren thought.
The camera's red light flickered.
It never flickered on Day One.
In Timeline Five, that same camera had followed him for three days straight before the sky split open.
Ren slid into his seat by the window and rested his chin on his hand.
[SYSTEM OBSERVATION ACTIVE]
The message didn't appear in the air.
It appeared inside his vision, like a reflection that didn't belong to his eyes.
Ren didn't react.
Reacting was how it learned.
The bell rang.
Students poured in, laughter filling the room, normality doing its best impression of safety. Ren watched them like ghosts-people he had seen die in seven different ways.
A girl sat down in the seat in front of him.
Black hair tied loosely. Slight slouch. A pen already spinning between her fingers.
Ren froze.
"...You weren't here," he whispered.
The girl turned around.
"Huh? Do I know you?"
Her eyes met his-sharp, curious, and wrong.
In every previous timeline, that seat had been empty until midterm.
Ren forced his expression to relax.
"Sorry. Thought you were someone else."
She studied him for a second too long, then smiled.
"Figures. Everyone says that to me."
She turned back around.
Ren's pulse hammered.
This was new.
New variables were dangerous.
[SYSTEM WARNING]
Unregistered entity detected.
Designation pending...
The girl's pen stopped spinning.
Slowly, she spoke-without turning around.
"Hey," she said casually.
"Why does it feel like you're not supposed to exist?"
Ren's blood went cold.
The system never spoke through people.
He stood up.
The classroom fell silent.
Every head turned toward him.
Ren smiled faintly.
"Well," he said, "I could ask you the same thing."
For a moment, nothing happened.
Then the windows cracked.
Not shattered-cracked, like reality itself had flinched.
[ERROR: ERROR: ERROR]
Causality divergence exceeding threshold.
Deploying Observer.
The girl finally turned around.
Her eyes were no longer sharp.
They were empty, like mirrors reflecting something far away.
"Run," she whispered.
"Before it sees you properly."
The classroom lights went out.
And something began knocking from the inside of the walls.