Wait. First hit bruised, second broke, third shattered. Each touch was twice as bad as the last.

  Same force. Different results.

  A memory flashed, the Harvesters. The first man’s wrist, bent backward. The second’s arm, limp as a rope. The third’s knee, collapsing inward like a failed load-bearing joint.

  His stomach turned.

  Not random. Not luck.

  First strike: baseline.

  Second strike: double.

  Third strike: quadruple.

  She was a walking algorithm of destruction. A cold thread of understanding pulled tight in his chest.

  Exponential growth.

  She wasn’t just strong. She was a recursive equation, every touch compounding the last, a silent algorithm of ruin.

  The name for it dropped into his mind, fully formed, as if the concept itself had forced its own label into existence.

  Crescendo.

  Her recursive technique. It had to be automatic. A built-in, self-escalating failsafe that triggered with each consecutive strike. A defense mechanism that didn't know how to de-escalate, only how to ensure the threat was permanently neutralized.

  The understanding hit him like a physical blow, and suddenly, her entire demeanor made a terrible, heartbreaking sense. The constant fidgeting, the way she held herself so carefully, the palpable fear in her eyes, it wasn't just social anxiety. It was the bone-deep terror of a person living with a live landmine for a nervous system. A single, accidental nudge in a crowded street, a startled flinch, a friendly pat on the back that landed a fraction too hard... and the algorithm would engage.

  He looked from the crumpled, wheezing man on the ground back to Butter. He finally, truly understood. A few accidental nudges, and he would be broken just the same.

  She shoved a gummy worm into her mouth like it might seal the apology. Chewed fast. Then offered one.

  “Want one?” she asked, meekly. “You probably don’t. I get that.”

  Brad stared at the crumpled man on the ground. Then back at her.

  A sudden scuff of a shoe on wet asphalt. A guttural yell.

  The lookout, who had fled earlier, returned. He charged from the shadows, a rusted crowbar held high, his face a mask of drunken rage as he sprinted directly toward Butter's undefended back.

  Brad didn't think.

  He moved on an instinct he didn't know he had. He pivoted, stepped into the man's path, and threw a single, desperate punch. It wasn't skilled. It was all shoulder and fear, a wild swing that connected with a sickening crack against the man's jaw.

  The man's eyes rolled back in his head. He dropped like a sack of bricks, the crowbar clattering harmlessly to the pavement.

  Silence, broken only by Brad's ragged breathing and the distant wail of the van's alarm.

  Butter stared, the gummy worm frozen in her outstretched hand.

  Brad shook the stinging pain from his knuckles, looking down at the two unconscious men. A hysterical laugh bubbled in his throat. He gestured at the scene, his voice thick with disbelief.

  "A grown man," he panted, "trying to sneak-attack a teenager." The sheer, stupid injustice of it all was almost funny.

  She looked like she wanted to melt into her hoodie and vanish.

  Not just shy. Ashamed.

  Brad stared at her, trying to look cool, trying to hide the fact that his hand was throbbing with a hot, sharp pain. He flexed his fingers subtly under the guise of shaking off the adrenaline, but the knuckles were already starting to swell. It didn't matter. The pain was a cheap price. A little ache in his hand was infinitely better than the soul-crushing guilt he knew she’d feel if her Crescendo had activated on the lookout. He’d seen the shame in her eyes after the thief; he wouldn't let her carry another body, even a metaphorical one, on her conscience.

  “He was being rude. To Mr. Henderson’s car,” she said, almost inaudibly.

  Her prosthetic hummed, a sound like a sleeping beast. Brad wondered what happened when it woke up.

  He took the gummy worm. Slowly. Not because he wanted sugar. But because she needed him to. She wasn't just strong, she wasn’t human, not entirely.

  And yet she looked more wrecked than the men she’d wrecked. She wasn’t just powerful. She was a live wire wrapped in apologies. Something broken. And brilliant. And trying.

  The rain still fell. But something far stranger had stepped into Brad’s life.

  And it wasn’t leaving.

  ///

  The rain had finally stopped, but the streets didn’t feel clean.

  They gleamed like open wounds beneath flickering lamps, steam rising from manhole grates and gutter streams whispering through trash and broken glass. Brad hunched his shoulders against the cold. The city seemed to breathe now, slow and uneasy.

  Stolen content warning: this tale belongs on Royal Road. Report any occurrences elsewhere.

  He kept glancing at her, Butter, chewing on a blue raspberry sour strip like she hadn’t just taken down a car thief with math magic.

  “So... that Cresendo thing,” he ventured, his voice a whisper. “Does it work on... everything?”

  Butter blinked slowly, letting the sour chew. “Maybe. Never tried it on a building. Probably rude.” She offered him a green strip.

  He reached for it, but she paused. “Wait... how'd you figure that out?”

  He shrugged his shoulders, "I'm very observant, I guess."

  She stared down at her prosthetic leg, the faint blue glow pulsing like a trapped heartbeat. Her voice, usually so hesitant, cut through the silence like glass.

  “You should go.”

  Brad blinked. “What?”

  Butter wouldn’t meet his eyes. “You saw what I can do. What I am.” She paused for a moment, then continued. “People like me... we’re not safe to be around.”

  A streetlamp flickered, casting her face in jagged shadows. For the first time, Brad noticed the scars, thin, silvery lines along her jaw, nearly invisible unless the light hit them just right.

  Like someone tried to erase her.

  He swallowed hard. “Yeah, well. People like me aren’t safe to be around either.” A bitter laugh escaped him. “I’m one missed paycheck away from living under a bridge. My ‘superpower’ is surviving on expired sardines.”

  Butter’s pink eyes flicked up, startled.

  “People who stay near me get hurt,” she insisted, fists clenched. “Not might. Will.”

  Brad shrugged. “People who stay near me get hungry. Pretty sure you’re winning.”

  Butter frowned.

  Brad kicked a pebble. “Look, I don’t know what the you are, but you didn’t have to help me back there. You could’ve walked away. But you didn't.”

  She opened her mouth, then closed it. Her fingers twisted in her hoodie sleeves. “I... I just didn’t want you to get hurt.”

  “Why?”

  The question hung between them, raw and unguarded. Butter hesitated. Then, so quiet the rain nearly drowned it out:

  “Because nobody ever does that for me.”

  Brad’s chest ached. He reached out, slow, giving her time to pull away. When she didn’t, he tapped her prosthetic with his knuckles, once, twice. The metal hummed under his touch.

  “Guess we’re both shit at self-preservation,” he said.

  Butter’s breath hitched. Then, like a dam breaking, she let out a laugh, small, startled, and real.

  She stared at her hands. “I blasted out the windows of a hospital once.”

  Brad blinked. “What, like with a—”

  “Not on purpose.” Her voice frayed at the edges. “I just sneezed, thrice.”

  He opened his mouth. That’s cool, almost slipped out, automatic, the way you laugh off anything too weird to process, but then he saw her eyes.

  Not embarrassed. Not joking. Ashamed.

  The kind of shame that hollowed you out. The kind you earned by waking up to shattered glass and screaming, by seeing your own hands and realizing they were weapons first, flesh second.

  Brad’s chest ached. He thought of Lissy’s hospital room, the way the machines had beeped louder than her voice by the end. How the walls had felt like they were pressing in.

  “Crescendo...” he said, the name feeling foreign and dangerous on his tongue. “It works on everything?”

  The implications unspooled in his mind like a nightmare. A handshake. A pat on the back. A hug. If every touch was a step in an exponential sequence, then how did she do anything at all? How did she pet a cat without turning it to paste? How did she get dressed without shredding the fabric? The sheer, constant, minute control she must have to exercise every second of every day just to exist in the world was a burden he couldn't even comprehend. It wasn't just a power; it was a prison.

  He didn’t ask if she’d been alone in that room. He already knew the answer.

  He didn’t say anything else. Just nudged her with his elbow, careful not to dislocate anything. When she didn’t flinch, he left it there. Warmth against warmth. Two kids who didn’t know how to be touched gently.

  For a second, she tilted into the contact, then stiffened, like she’d remembered her bones were made of grenades.

  Butter’s prosthetic whirred, the blue glow pulsing faster. Like a heartbeat. Like a warning. Brad pretended not to notice.

  A flicker of movement in his periphery. Butter’s fingers twitched. The candy fell from her hand.

  Brad frowned. “What's wrong?”

  Her pupils dilated. The streetlamp above them buzzed, then died. Shadows pooled at their feet like spilled ink.

  Butter’s voice was a blade. “Don’t move.”

  Brad froze. He didn’t see anything. Didn’t hear anything. But the air itself felt charged, like the moment before a lightning strike.

  Then Butter’s prosthetic leg pulsed, a single, frantic blue flare.

  And the world exploded.

  Then there was a sound like air collapsing. A blur moved faster than his brain could track, Butter was ripped from beside him and slammed into the side of a van. For one suspended moment, she was weightless, limbs splayed like a broken starfish.

  Then: impact. BAM!!!

  She hit the van back-first like a cannonball, metal buckling around inward in a perfect silhouette of her body. The van’s frame lurched sideways, tires screeching against asphalt as the suspension buckled. Inside, the dashboard cracked from the shockwave, the radio sparking as wires tore loose.

  The tempered glass burst into diamonds, showering the street in a glittering hail as the force traveled through the frame. The van’s alarm wailed, a dying animal’s scream.

  Butter embedded in the steel, her hoodie snagging on twisted edges, before slumping forward with a wet gasp, the wind knocked out of her like a corpse revived mid-autopsy. Her hoodie was shredded at the seams where the steel had bitten into her back.

  Brad’s vision swam. The van’s alarm wailed like a dying animal, but all he could hear was the thud-thud-thud of his own pulse. His hands shook. His lungs burned.

  Butter was standing.

  No, not standing. Unfolding.

  Her hoodie was shredded at the seams where steel had bitten into her back, but the pale skin beneath was unbroken. Not bruised. Not bleeding. Just... there. Like concrete after a hailstorm: scuffed, but fundamentally unchanged.

  "That impact was at least 80 mph," his brain supplied, unbidden. "Human body hits solid metal at that speed, ribs puncture lungs. Spine snaps. Organs liquefy."

  But Butter? She’d embedded in the van. The metal had warped around her. His stomach lurched.

  "That’s not possible."

  But his mind, traitorously sharp, kept working.

  Unless her tissues are denser. Unless her bones aren’t really bones. Unless she’s not human at all.

  Brad’s brain itched with equations.

  Force = mass × acceleration.

  Human femur fractures at ~4,000 newtons.

  That impact was 50,000+. Minimum.

  His eyes, wide with fear, scanned her now like a schematic.

  Data Point: The prosthetic leg. Advanced, unknown power source. Not medical. Industrial? Military? Its integration is seamless, suggesting either perfect adaptation to her biology or that the biology was designed to adapt to it.

  Data Point: The exponential force application. A controlled, mathematical escalation of kinetic energy output. Not emotion-driven. Algorithmic.

  Data Point: The hands. No calluses. No scars. Pristine. The hands of a newborn or a... prototype. Never worn, because they cannot be worn down.

  Data Point: The appetite for sugar. A high-calorie fuel source for a high-output system? A biological imperative, or a programmed behavioral quirk?

  The pieces clicked together, forming a horrifying, inescapable conclusion. This wasn't a person who had been given powers. This was something that had been built. Engineered. Her strength wasn't an addition; it was her base state. Her bones weren't fortified; they were likely something else entirely. Carbon nanotube lattice? Forged alloy? Theories flashed and died, inadequate.

  She was less a superhero and more a... sentient wrecking ball. A living, breathing piece of impossible physics, wrapped in a cheap hoodie and a layer of profound, tragic shame.

  Butter flinched. And just like that, the numbers evaporated. The fear rushed back in. Because whatever she was, whatever he was noticing, it didn’t matter right now.

  A movement on his right. He saw her, a figure stood now, poised atop a taxi cab like she belonged there. Her presence radiated from her in a way that made the shadows cling to her, like a setting sun. Braided long black hair, streaked with white, glistened under the lamps. Glistening double gold hoop earrings caught the sickly light, framing a face of sharp, impossible angles.

  She was beautiful, Brad realized with a jolt of pure, unadulterated terror.

  It wasn't a human beauty. It was the lethal, fluid grace of a predator, a panther poured into the shape of a woman. She moved with a silence that felt like a threat, her poise so unnerving it seemed a wizard had conjured her from a cat's soul and shadow. The only thing missing was a tail twitching in predatory amusement.