Rei didn't sleep.
Not because he couldn't—but because his body refused to.
Every sound echoed too loudly. Every movement in the dark registered as a threat. His heartbeat stayed steady, controlled, like it no longer needed rest.
He sat against the cold subway wall, breathing slowly.
Listening.
Mitsuki watched him from across the platform.
She had wrapped her tail tightly around her waist, fingers digging into her sleeves. Her ears twitched every time Rei shifted.
"You're not shaking," she said quietly.
Rei glanced at his hands.
They were steady.
"That's bad, isn't it?"
Mitsuki swallowed. "…It means your body is still changing."
She approached carefully, like she wasn't sure if Rei was still the same person.
He noticed.
That hurt more than the pain in his neck.
"I'm still me," he said.
Mitsuki stopped in front of him. Her eyes searched his face, not for lies—but for danger.
"I know," she whispered."That's why I'm scared."
Above ground, the city sealed itself off.
Roadblocks.Emergency broadcasts."Gas leaks.""Routine inspections."
Lies stacked neatly on top of fear.
Far beneath them, something else was waking up.
Director Kagami screamed.
Not in pain—in ecstasy.
Bones shifted. Skin hardened. Muscles rewrote themselves in seconds. His spine elongated, tail ripping through fabric. Scales bloomed across his arms like black glass.
Then—
He inhaled.
Exhaled.
And pulled himself back together.
Human again.
Perfectly.
The room fell silent.
Kagami smiled.
"So this is what you tried to steal," he murmured.
Back in the subway, Rei stood abruptly.
Mitsuki flinched.
"Someone's coming," Rei said.
His voice was calm.
Too calm.
"How many?" Mitsuki asked.
Rei closed his eyes.
"…One."
Her blood ran cold.
"One meant command.
One meant him.
They moved deeper underground.
As they ran, Rei noticed things changing.
His vision adjusted to darkness effortlessly. His muscles responded before he told them to. Fear didn't freeze him anymore—it sharpened him.
"I can feel it," he said between breaths."My body keeps… fixing itself."
Mitsuki's jaw trembled. "That's how it starts."
They reached an abandoned maintenance chamber.
Dead end.
Mitsuki stopped.
Rei turned to ask why—then felt it.
Pressure.
Like the air itself was being crushed.
Applause echoed through the tunnel.
Slow.
Deliberate.
A man stepped into the dim light.
Tall. Immaculate suit. Calm smile.
Director Kagami.
"Incredible," he said."A rat that learned to love… and a boy who learned to evolve."
Mitsuki hissed, body lowering instinctively.
"You should've stayed in your cage," Kagami said gently.
Rei stepped forward.
"No," he replied."She should've never been put in one."
Kagami tilted his head.
"Oh," he said."So the mutation speaks."
His eyes flashed.
Something moved beneath his skin.
Mitsuki grabbed Rei's arm.
"Don't fight him," she whispered desperately."He doesn't stop changing."
Rei met her gaze.
Neither did he.
The lights exploded.
Concrete shattered.
And evolution finally showed its teeth.