S.H.I.E.L.D., the subterranean secret training facility beneath the Triskelion Headquarters.
This was North America's most advanced single-combatant testing center, its cavernous interior as vast as a hollowed-out mountain. The air carried the distinct scent of ozone and cooled metal, while an array of matrix-style floodlights illuminated the space in blinding white brilliance.
A deep-black synthetic track encircled the entire facility, its unusual surface shimmering faintly—this was no ordinary material. A cutting-edge Stark Industries kinetic absorption and feedback alloy, it had been designed explicitly for superhuman-speed testing.
At the starting line, Steve Rogers flexed his wrists and ankles, the faint crack of his joints echoing in the silence.
He wore a brand-new suit—predominantly a deep navy blue, with the familiar red-and-white star and stripes emblazoned across his chest and shoulders. But this suit was sleeker and more form-fitting than anything he had worn before. Along the joints, fine, almost biological-looking fibers pulsed with a dark, muscle-like texture.
This was the prototype Paul had custom-built for him—the "Magnetic Levitation Disc" suit. A ridiculous name, but its performance was beyond terrifying.
"You ready, Cap?"
Paul's voice crackled through the intercom, youthful and unrestrained with excitement. "All sensors calibrated, kinetic feedback system online. Just remember—push your limits today. We need real data."
Steve raised a thumb toward the observation deck, then took a deep breath.
Super-Soldier serum surged through his veins, his body honed to four times peak human performance. The world seemed to slow, fading into the background until all that remained was the rhythm of his own heartbeat.
"Go!"
A dull boom split the air as Steve vanished from the starting line.
His posture was low, his legs churning in a blur beyond human perception. The sheer force of his sprint sent shockwaves rippling through the air, rattling warning signs along the track.
He wasn't running—he was flying.
Against the black track, his dark-blue form left behind what looked like a solid, lingering afterimage.
In the observation room, a group of white-coated agents stood frozen, mouths agape as holographic displays tracked the impossible numbers.
"Sweet mother of—he's still accelerating!"
"He's hitting the curve—and he's not slowing down!"
Steve leaned into the first high-speed turn at an impossible angle, his boots nearly parallel to the ground. A faint blue arc of energy erupted beneath his feet—the suit's stabilization engine compensating for the brutal centrifugal force.
He was a blur, a streak of motion more than a man.
"300 meters per second… 315… 320…!" Paul's voice trembled with exhilaration, his knuckles whitening around his tablet.
The readings inched toward the sound barrier.
And this was on the ground, powered by nothing but raw physical strength.
Steve's blood burned. The wind howled in his ears, no longer sound but pressure. He could feel it—a threshold, just out of reach. One final push, and he would break past sound itself.
Then—
"Stop! Steve, STOP!"
Paul's panicked yell tore through his focus.
Steve instinctively reacted, boots slamming down as twin alloy brake panels snapped out from his heels. Sparks screamed against the track, twin black scorch marks tracing his path as he skidded to a perfectly controlled halt just shy of the end line.
Breathing hard, he turned toward the observation room, his exhales crystallizing in the air.
Paul came barreling out of the control room like a man possessed, emotions warring between euphoria and sheer terror.
"Are you insane?" he wheezed, pointing upward. "You were about to cause a sonic boom underground! You realize the whole base would've thought it was a freaking earthquake? My equipment wouldn't survive that kind of shockwave!"
Steve gave a sheepish grin. "Got carried away."
"Carried—? You were about to punch a hole in reality!" Paul shoved the tablet under his nose, fingers shaking. "But look at this! 330 meters per second—Mach 0.97! Good God, you're basically a human-shaped missile!"
Steve blinked at the impossible number. He had known he was fast, but this—?
"Credit where it's due," he said, rapping the suit's chest plate. The lightweight material had amplified his every stride, its kinetic feedback turning each motion into raw acceleration.
"Please. The suit's just the wheels—you're the damn engine." Paul's eyes gleamed with dangerous inspiration. "Imagine if we hooked this up with the 'Accel World' module—neural-linked reflexes boosting your reaction time tenfold. Hell, at that point, you wouldn't just break the sound barrier. You'd be playing tag with light!"
Steve had no idea what any of that meant, but he handed the tablet back. "Results are good enough for me. What's next?"
For the first time in decades, he didn't feel like a soldier thawed from a bygone era. Just a man who'd been given the keys to something exhilarating.
Test Two: Defense.
A massive target panel rose from the center of the training floor. Twenty meters away, a monstrous, modified rifle stood mounted. Its barrel was the width of a man's fist.
"Barrett M82—Special Forces custom," Paul announced. "12.7mm tungsten-core armor-piercing round. Muzzle energy over 20,000 joules. At two klicks out, it punches through light tanks."
Steve stood before the target, gripping his circular shield.
At first glance, it was identical to his old vibranium shield—same red, white, and blue, same gleaming star at its center. But this one was crafted from Paul's new composite alloy: high-density vibranium at its core, coated in an energy-deflecting outer layer.
"Ready," Steve said, bracing.
"Fire!"
BANG—
The concussion was deafening. The rifle spat fire as the projectile spiraled across the room—
—and struck the shield's center dead-on.
But instead of a titanic impact, the star flared blue. A visible wave of energy rippled outward, liquid-like, dispersing the force.
The tungsten round, capable of gutting a tank, slowed. As if hitting deep water. Then, smoothly, it slid off the shield's face and clattered harmlessly to the floor in a mangled lump.
Steve barely felt the transfer.
"Perfect," he murmured.
"Energy-dispersal coating," Paul smirked. "Doesn't block—just redirects. As long as the force stays under threshold, it could deflect a damn artillery shell."
Steve hefted the shield, testing its weight. The balance was nearly identical to his original. Only one test remained.
"Final phase: Throwing performance."
At Paul's cue, ten drone targets emerged from hidden compartments—each moving unpredictably, darting through the air or skittering across the ground.
Steve smirked. For him, this was barely a warm-up.
But Paul didn't give the signal. Instead, the kid leaned back, arms crossed, wearing a look.
"Problem?" Steve asked.
"Nah. Just thinking we're underselling this." Paul's grin widened. "A basic throw test? For you and that shield? Too easy."
Steve arched a brow. "Got something else in mind?"
Paul snapped his fingers.
"JARVIS. Activate—Storm Protocol."
Instantly, the drones erupted.
Their speed doubled, their movements chaotic—zigzagging, rolling, even cloaking behind each other in erratic patterns. A nightmare trajectory.
Steve tensed.
This wasn't just about accuracy anymore. It demanded computational reflex—near-clairvoyant prediction.
And Paul wasn't done.
"One more rule," he said, devilish. "Only one throw."
"One?" Steve frowned. "You want me to hit all ten targets—in a single toss?"
Impossible. No angle, no rebound could cover the entire field.
"Exactly," Paul said, eyes alight. "Throw it once."
Then, with a knowing gleam—
"But don't overthink it, Cap. Give the shield an order.
Tell it… to fly."