The entrance to the NeuroSim Vault was locked behind two biometric scans and a retina passcode. Only three people in the entire ValeTech building had access to it.
Renji Vale.
Dr. Lena Cero.
And now—Lior Ahn.
The walls pulsed with faint light as if alive, glowing gently with soft blue veins of electricity beneath the surface. Inside the vault, a circular pod stood in the center—like a sleep chamber crossed with an MRI scanner, surrounded by floating holographic rigs.
"Simulation Chamber Omega," Renji announced. "It models a full human brain—every synapse, every microglia, down to neurotransmitter flow. It's used to test decision-making under high-stress neurological conditions."
Lior was still trying to process the sheer scale of it.
"You made this?"
"I designed the neural logic. Lena coded the rest." Renji's tone was matter-of-fact.
A second later, the system whispered in Lior's mind.
> [Advanced SimTech Detected. Preparing Compatibility Bridge.]
[New Skill Unlock Available: Cognitive Overclock Lv.1]
[Warning: Emotional Input High. Risk of Psychological Feedback.]
He looked at Renji. "And you want me to test this?"
"No. I want to see how far you'll go before breaking."
Lior narrowed his eyes. "That's a twisted way of showing mentorship."
Renji smiled faintly. "Mentorship is for med school. I offer evolution."
---
Inside the Pod
As Lior lay back, the interface locked around him with a hiss. Cool air flooded the chamber, and within seconds, he was immersed in the simulation.
It wasn't abstract.
It was real.
He stood in a brightly lit operating theater, gloved, masked, and surrounded by virtual assistants.
A girl, no older than eight, lay on the surgical table. Her scans hovered in the air: High-grade glioblastoma. Location: Brainstem. Survival chance: < 6%.
The AI spoke:
> "Patient is slipping. Surgery required. Time limit: 18 minutes."
Lior's hands moved instinctively. The system supplied anatomical overlays, critical margins, neuron protection zones.
His breath hitched. The tumor was tangled with motor control clusters. One wrong cut and the girl would lose the ability to breathe.
> [Cognitive Overclock Activated: Lv.1]
The world slowed.
He moved faster, smoother—identifying safe paths, rerouting neural currents.
But the girl's voice echoed inside the sim.
"Will it hurt?"
She looked so… real.
His hands trembled.
> [Warning: Emotional Contamination Detected.]
He took a breath, focused harder. He was here to save lives. Emotions had to wait.
Cut. Remove. Seal. Close.
Beep.
Flatline.
> [Simulation Failed.]
The lights dimmed. Everything went dark.
---
The chamber opened.
Lior gasped, drenched in sweat. His body trembled like he'd actually lost someone.
Renji stood at the control panel, unreadable.
"You lasted 17 minutes and 11 seconds," he said. "Not bad for a first time."
Lior sat up slowly, his voice hoarse. "I didn't lose because of technique."
"No," Renji said, walking closer. "You lost because you care."
There was no mockery in his voice. Only… analysis.
"Empathy is useful in the clinic," he continued. "But in neurosurgery? It gets you killed."
Lior looked up. "Then maybe it's time someone changed that rule."
For the first time, Renji paused.
Then he turned, hands behind his back.
"Your system chose you for a reason," he said softly. "Let's see if you can change more than just rules."
---
Later That Night
Back in his room, Lior stared blankly at his ceiling, brain still reeling from the sim.
> [Simulation Debrief Available]
[Emotional Processing Lv.1 Unlocked]
[New Quest: Successfully Complete Critical Pediatric Brain Surgery in Sim]
[Reward: Skill Tree - Neuroanomaly Recognition Lv.1]
The ceiling seemed to whisper back at him:
"Will it hurt?"
Lior covered his eyes.
He didn't want to become a cold machine.
But he didn't want to fail again, either.
He would need to find balance between intellect and heart.
Between his system… and his soul.
And maybe, just maybe, Renji wasn't as heartless as he acted.
Because when Lior failed that little girl in the simulation—
Renji had looked away.
Almost like it hurt him, too.