Chapter 5: The Equation of Ruin
"Your speed..." Yuta murmured, his breathing still shallow from the sudden adrenaline spike. He stared at the empty street where the thief had vanished. "If you hit him... the margin of error is zero. But... what if the target was suddenly fifty kilograms heavier? He couldn't run."
Sora slowly turned her head. The lingering frustration in her brown eyes was suddenly pierced by a sharp, dangerous curiosity. She looked at Yuta, then down at her overturned skateboard lying on the concrete path.
"You mean... making him heavy without actually touching him?" she asked, her voice hushed, as if speaking the idea aloud might break it.
"Not him," Yuta corrected, stepping toward the abandoned piece of sporting equipment. He picked it up by the curved tail. The wooden deck was scuffed, covered in cheap stickers, and completely ordinary. "We transfer the mass. You provide the velocity. I provide the density. A moving projectile."
The sun had dipped below the horizon, painting the park in deep shades of twilight blue and casting long, distorted shadows. The elderly citizens had gone home, leaving the paved pathways completely deserted. It was the perfect, isolated laboratory.
Sora took the board from his hands, her fingers tracing the rough grip tape. "My 'Momentum Shift' lets me maintain the force of my initial push," she explained, pacing out a distance of about ten meters. She drew a line in the gravel with the heel of her shoe. "I kick it from here. It shoots forward like a hockey puck. You stand in the middle, touch it as it passes, and make it dense."
Yuta positioned himself halfway down the path, crouching slightly. He calculated the trajectory. It sounded simple in theory. Two basic actions intersecting at a single point.
"The timing has to be exact," Yuta warned, his eyes narrowing as he focused on the plastic wheels. "If I activate my trait too early, the sudden weight will stop it instantly, or shatter my fingers. Too late, and I miss the window entirely."
"Just don't miss," Sora replied, a nervous, entirely unconvincing grin on her face. She dropped the deck onto the pavement. Clack.
She took a deep breath, stepping back. Then, with a sudden burst of athletic energy, she lunged forward, stomping her back foot onto the tail while simultaneously kicking the board forward with her front foot. It was a flawless, high-speed launch.
The skateboard rocketed across the smooth concrete, a low, rumbling blur aimed directly at a sturdy oak tree twenty meters away.
It approached Yuta in a fraction of a second. He reached down, his hand hovering millimeters above the path. The roaring sound of the wheels filled his ears.
Now.
His fingertips brushed the speeding grip tape. He mentally pulled the trigger on his 'Density Shift'.
The physical backlash was instantaneous and catastrophic.
The wooden deck, traveling at roughly twenty-five kilometers per hour, suddenly possessed the mass of a solid lead anvil. The cheap metal axles connecting the wheels to the board were never engineered to withstand such an extreme, contradictory collision of forces.
CRACK.
It sounded like a gunshot. The metal trucks sheared completely off the bottom of the board with a shower of orange sparks. The dense, incredibly heavy wooden deck slammed straight down into the concrete with the force of a meteor, gouging a fist-sized crater into the pavement before violently flipping upward.
Yuta threw his arms over his face, falling backward into the dirt as splinters of wood and stray plastic wheels shrapneled into the nearby bushes.
Silence descended violently upon the park, save for the solitary spinning of a broken wheel settling onto the grass.
Yuta lowered his arms, coughing slightly from the dust. He looked at his hand. His fingers were trembling uncontrollably, the skin scraped red, though thankfully unbroken.
Sora rushed over, her eyes wide with undisguised shock. She stared at the small crater in the concrete, then at the jagged, heavy piece of plywood embedded in the dirt a few feet away. Her favorite mode of transportation was utterly annihilated.
"Are you okay?" she asked, her voice cracking slightly, the reality of the danger finally sinking in.
"My reaction time is too slow," Yuta stated flatly, ignoring the stinging in his palms. He didn't apologize for the broken equipment; they both understood the risk they had taken. "Human biology is the bottleneck. The transfer of kinetic energy was successful, but the structural integrity failed because my activation was delayed by approximately zero-point-two seconds. The front wheels caught the artificial weight before the rear wheels did."
Sora slumped onto the ground next to him, pulling her knees to her chest. The adrenaline crash was hitting them both hard. "So, we have the gun, and we have the bullet. But we can't aim it, and we can't pull the trigger without blowing our own hands off."
Yuta looked at the shattered wood. He pictured the pink-haired girl from their classroom, the one who could track movement with terrifying, disciplined precision. He then thought of the boy with the loud voice and the yellow sweater, whose erratic energy naturally drew every eye in the room.
"We lack a metronome," Yuta said quietly, the pieces of the puzzle slowly sliding into place within his mind. "We need someone who can see the exact frame of impact. And we need a distraction so the target doesn't simply step aside."
Sora looked at him, catching his drift perfectly. The competitive, stubborn spark returned to her eyes. "Monday morning," she stated, getting up to collect the sad remnants of her board. "We need to talk to the Samurai and the Spark Plug."