The lecture hall smelled like old carpet and ozone, the way the physics building always did after a long night of experiments. Yuan He had learned to love it: that thin edge in the air that meant something had been pushed, heated, coerced into behaving.
He stood behind the podium with his laptop open, a laser pointer in his palm, and a glass of water he hadn't touched. On the first row, his adviser sat with arms crossed, expression carved into neutrality. Two faculty members from the department were there, along with a half-dozen grad students who looked like they'd slept in hoodies and survived on vending machine coffee.
His title slide glowed on the projector.
Toward Practical Confinement: A Low-Field, High-Stability Approach to Net-Positive Fusion
He clicked once.
"Good morning," he said, and his voice didn't crack. "Thank you for coming. I'm going to walk you through the confinement architecture we've been building, the stability problem everyone told me I couldn't solve, and why I think we finally have a path that scales."
The next slide was a diagram: rings, coils, field lines braided into a shape that looked obedient. Beautiful, in the way only equations made visible could be. He spoke the way he'd learned to speak to committees: start with what they already believed, then slide a blade under it.
"Tokamaks have their strengths," he said. "They also have instabilities that grow teeth the moment you push performance. Most designs try to overpower the plasma. We tried to cage it."
He clicked again, and the room settled into listening.
"This is a low-field approach," he continued, pointing at the outer coil arrangement. "Not because I want low performance. Because I want control. We built in passive stability first, and then we added power. We allow controlled motion within constraints, so the system has time to correct and time to fail safely."
His adviser didn't move. That meant nothing. It also meant everything.
Yuan He let himself breathe. The slides flowed: design principles, simulations, hard numbers. He didn't drown them in derivations. He gave them the spine.
"Here's the key," he said, circling the place where his design diverged from the standard. "If you clamp everything at once, you get brittle behavior. It holds until it doesn't. We instead..."
A vibration passed through the floor.
Faint, like a truck going by outside.
Then again, stronger. The lights flickered as if the building hesitated mid-thought.
A few people glanced around, uncertain smiles forming and dying.
Yuan He's stomach tightened before his mind caught up. He had checked the dashboard ten minutes ago. It was supposed to be conservative. It was supposed to stay boring.
He clicked out of his presentation without thinking and pulled up the monitoring page.
The numbers were wrong.
Field strength increasing. Temperature rising. Vibration sensor spiking.
A red banner stacked under the other, then another.
His hands went cold.
It wasn't just "wrong." It was wrong in a way he recognized.
A week ago, in a fog of deadlines and caffeine, he'd pushed a last-minute patch to the monitoring layer, just the display mapping, he'd told himself. He'd been cramming for the defense and fighting the kind of fatigue that made simple things feel negotiable. He'd renamed channels, reorganized indices, promised himself he'd re-run the full calibration suite in the morning.
He hadn't.
Now the UI was screaming, late and out of order, because it had been listening to the wrong heartbeat.
Somewhere beneath them, a machine he'd built to be stable was being fed a lie.
Another whump came from below. Not a boom yet, just the promise of one.
His adviser stood, sharp as a snapped line. "Is that-"
"Everyone needs to get out," Yuan He said, and his voice turned hard enough to cut. "Now."
For half a second, nobody moved, because adults in nice clothes don't like being told to run in a university building. Then the floor shuddered again and the room remembered it had legs.
Chairs scraped. People surged toward the doors. Someone swore. A fire alarm began its flat, relentless wail.
His adviser appeared beside him. "Basement?"
"Yes," Yuan He said, already moving.
"Don't be stupid," his adviser snapped.
Yuan He didn't answer. He was already sprinting.
The stairwell smelled like concrete and fear. People flowed upward, shouting, phones up, eyes wide. Yuan He took the stairs down two at a time, because the basement was where the reactor assembly was and the reactor assembly was where the mistake was, and if there was any chance to keep it from becoming a headline about dead students, he had to take it.
He hit the basement corridor and the air was warmer already. A low roar rolled through the walls like a storm held captive.
The lab door was half-open. Light pulsed inside, not the cold fluorescence of the building, but something brighter, strobing, wrong.
Two undergrads, lab assistants he'd begged from the department, stood frozen in front of the main monitor, faces bloodless.
"Out," Yuan He barked. "Both of you. Now!"
They flinched like he'd struck them and bolted. One of them hesitated at the doorway, eyes darting toward the reactor. "What do we do?!"
Yuan He pointed down the corridor without looking away from the screen. "Stairs. Up. Keep people moving. Do not stop!"
The student ran.
Yuan He's gaze flicked over the readouts and finally, finally, saw the real problem beneath the noise: cooling loop pressure falling, but the interlock still reading "nominal" because the wrong channel was being trusted. His patch hadn't caused the failure, but it had blinded his warnings until the failure had teeth.
He crossed to the emergency panel. The quench indicator blinked yellow.
He slammed the quench lever.
Nothing.
The system refused. The safety logic was engaged, software that assumed sensors were honest and uncertainty meant "don't act." A flat-lined channel meant it couldn't confirm. It wouldn't allow a quench because it didn't want a rash, catastrophic choice.
It was about to make a slower, worse one.
"Come on," he hissed, fingers flying across the manual override. "Come on!"
The coils' hum rose, a rising note like a scream building in the back of a throat.
Footsteps thundered in the corridor. His adviser's voice cut through the alarm. "Yuan He!"
He didn't turn.
He ripped open the interlock cabinet and found the jumper array. His breathing came too fast. The vibration became a savage, steady tremor. Metal somewhere deep in the assembly began to complain.
"Everyone's out of the stairwell!" his adviser shouted from the doorway, voice strained as he waved someone away behind him. "Campus security is clearing the floor!"
That sentence hit Yuan He like a hand on his spine. It meant the building above was emptying. It meant there was no one left to save except the people still too close.
He made a choice.
He pulled the jumper.
The interlock released with a click so small it felt obscene.
He slammed the quench again.
This time the indicator snapped to green. The hum shifted down, the way a pressure cooker sighs when it finally gives up steam. Energy began to dump into the resistive banks. Heat blossomed through the system and the air took on a sharp, burning edge.
For one second, the graph lines on the monitor started to flatten.
For one second, he thought he'd done it.
Then the reactor assembly gave a sound like a giant snapping a tree.
A coil housing fissured, a hairline crack blooming into a glowing seam. White-blue light flared behind it, stored energy trying to become motion, trying to become disaster.
His adviser took a step into the lab, stupidly brave. "Get out of there!"
Yuan He looked past him, down the corridor, and saw the flow of fleeing bodies was gone. Only flashing lights and the empty hall remained. The undergrads were nowhere in sight.
Good.
There was time for one more action, and it wasn't on a screen.
He lunged to the far side of the emergency panel and grabbed the heavy isolation shutter, a blast door meant to seal the lab from the corridor. It was designed for chemical spills and small fires, not this. It took both hands and all his weight to pull it down.
Metal groaned. The shutter dropped a foot.
His adviser reached him, grabbed his shoulder. "Yuan-"
Yuan He shoved him backward with a strength he didn't know he had. "Close it!" he yelled. "Don't argue, close it!"
His adviser stumbled into the corridor, shock on his face turning into understanding.
Yuan He hauled the shutter down again. It dropped, almost sealed.
The white-blue light behind him intensified, turning his shadow into something sharp and unreal against the wall. The reactor's roar deepened into a tearing sound, as if the room itself were being unzipped.
He thought, absurdly, of his slides. Of the neat lines. Of the phrase he'd used: fail safely, as if the universe respected footnotes.
He thought of the patch he'd told himself was harmless, the calibration he'd postponed, the way he'd tried to out-run fatigue with pride.
He thought: Containment. Always containment.
He heard the shutter slam from the other side, his adviser completing the seal. He heard the scrape of a lock mechanism engage.
He smiled without meaning to, a small, bitter thing.
At least this time, the blast wouldn't climb the stairwell.
At least this time, nobody else would die because he had been tired and arrogant.
The reactor let go.
The lab became light.
There was no pain at first. Just heat and pressure and the sensation of being flung backward through a tunnel. His lungs tried to inhale and found nothing. His body tried to exist and found it had been outvoted.
Somewhere in the collapsing white, a single thought rose, clear as a bell.
I finally made it stable. Just not for me.
Then the world snapped like a wire breaking under load, and everything went black.