Chapter 11: The Experiment's Price
The coffee was bitter, overbrewed and left too long on the warmer. Hyukjae sipped it black, the scalding liquid doing nothing to cut through the heavy silence that had settled over Donghae’s kitchen. She—he—fuck, the pronoun was a mental stumble each time—sat at the small table, wrapped in one of Donghae’s oversized hoodies. It swam on her frame, the cuffs covering her hands, the fabric smelling faintly of his detergent and, underneath, them. The sex from hours before, from the frantic floor coupling, lingered like a ghost.
Donghae moved around the kitchen with a quiet efficiency. He washed the few dishes, wiped down the counters, his movements precise. He was giving her space to think, to breathe. The kindness of it grated against the raw edge of her panic.
“I don’t have any clothes,” she said, her voice still hoarse from crying, from screaming. It was higher than she remembered. Lighter. “That fit.”
Donghae paused, a dish towel in his hand. “We can stop at your place.”
“My place has boys’ clothes.” The words felt like ash in her mouth. “The temporary ones I wore… before. They’re buried somewhere. I don’t even know if they’d…” She gestured helplessly at her chest, the new weight of it obvious even under the bulky sweatshirt.
“We’ll figure it out.” He came over, placing a hand on her shoulder. His touch was warm, solid. An anchor. “Heechul first. Answers first.”
“Answers,” Hyukjae repeated, scoffing. The sound was bitter, unfeminine in a way that was uniquely her. “He’ll just look at me like a bug on a slide.”
“Then we’ll make him see the person,” Donghae said, his voice low. “Not the experiment.”
They took the subway, a decision that felt like a descent into a gauntlet. Hyukjae kept the hood up, hands buried in the pockets, shoulders hunched. Every reflection in the dark train windows was a betrayal. The curve of a cheek, the fall of hair against a collar. She caught Donghae watching her, his gaze scanning the other passengers, a protective guard. He stood close, his body a shield between her and the world.
The walk to the Applied Bio-Sciences building was worse. The crisp autumn air felt exposed. Every rustle of leaves, every distant laugh, seemed aimed at her. Donghae’s hand found hers, linking their fingers together. The gesture was bold, declarative. She clung to it, her smaller hand swallowed by his.
Heechul’s lab was on the fourth floor, at the end of a long, echoing corridor that smelled of antiseptic and ozone. The double doors, with their etched, faded equations, stood like a portal to another realm. Donghae didn’t knock. He pushed them open.
The wave of scent hit first—burnt coffee, sharp alcohol, and that underlying floral note, cloying and unnatural. Like rotting lilies. The main lab was a cavern of stainless steel and white laminate. Banks of monitors glowed with undulating graphs. Glass cages lined one wall, empty now. In the centre, Professor Kim Heechul stood bent over a spectrometer, his silver-blond hair a shock against the sterility. He wore a pristine lab coat over a black silk shirt.
He didn’t look up as they entered. “Payment for the door repair is due by Friday, Donghae-ssi. Reinforced steel isn’t cheap, even for a budding lab assistant with a temper.”
“Look at me,” Hyukjae said. The command ripped from her throat, clear and cold.
Heechul went still. Slowly, he straightened, turning. His sharp, handsome face was a mask of academic curiosity. His eyes, a pale, calculating grey, swept over Hyukjae from head to toe. He didn’t seem surprised.
“Ah,” he breathed, a smile touching his lips. It wasn’t warm. It was the smile of a chess player seeing a predicted move. “The recurrence. Fascinating. The timeframe is accelerated from my projections.”
“Cut the shit, Heechul,” Donghae snapped, stepping forward. “What’s happening? He changed back last night. He was himself. And now this.” He gestured at Hyukjae, the movement fraught with a fury he was barely containing.
“‘He’?” Heechul tilted his head, tapping a stylus against his chin. “Interesting adherence to the original pronoun. A psychological anchor, perhaps. Tell me,” he said, focusing on Hyukjae, “was the reversion preceded by any intense emotional or physiological event? A surge of adrenaline? A state of heightened… satisfaction?”
Hyukjae felt the blood drain from her face. She saw Donghae stiffen beside her.
Heechul’s smile widened. He walked closer, circling her like a specimen. “The cellular matrix is adaptive, you see. It learns. It seeks equilibrium. The first transformation was triggered by the catalytic agent, yes, but subsequent shifts…” He stopped in front of her, peering intently. “They may be seeking a stable state. A preferred state. Triggered by bonding events. A chemical recalibration via, say, intimate exchange.”
“What the fuck are you saying?” Donghae growled, moving to put himself between Heechul and Hyukjae.
“I’m saying,” Heechul said, his voice dropping to a conspiratorial whisper, eyes glittering with unholy excitement, “that the transformation might be tied to sexual climax with a male partner. The body, in its fluid state, interprets the event as a… directive. A rewriting of the base code towards a compatible form. Fascinating, isn’t it? The body craving completion.”
The room tilted. Hyukjae’s hand flew to her mouth.
“So every time we…” Donghae couldn’t finish the sentence. His face was pale, horrified.
“Could very well reset the cycle,” Heechul finished, nodding briskly. He turned and strode to a whiteboard, covered in dense, spidery equations. “We need to test the parameters. Is it any male partner, or is there a bonding element? A specific pheromonal signature?” He spun back, stylus poised. “Hyukjae-ssi, you mentioned the university rugby team found you quite captivating in your previous feminine iteration. Perhaps we could arrange a controlled—”
Donghae moved.
It was a blur of rage. He crossed the room in three long strides. His fist connected with Heechul’s jaw with a sickening crack, snapping the professor’s head to the side. Before Heechul could crumple, Donghae grabbed a handful of the silk shirt and lab coat and slammed him backward into the steel shelving unit. Glass vials rattled and jumped; one fell and shattered on the floor.
Heechul grunted, dazed, a thin trickle of blood seeping from the corner of his mouth. His academic curiosity had vanished, replaced by a flicker of genuine fear.
Donghae got in his face, his nose inches from Heechul’s. His voice was a low, guttural snarl, every word layered with venom. “You listen to me, you soulless prick. She is not your experiment. You do not look at her. You do not think about her. You do not speak her name. You fix this. You reverse it. Permanently. Or I will take this entire lab apart with my bare hands and feed you the pieces.”
The feral possessiveness in Donghae’s eyes wasn’t just anger. It was something darker, more primal. A boundary etched in blood. Hyukjae, frozen by the doorway, felt a jolt go through her—not of fear, but of a shocking, deep-seated thrill. The violence was terrifying. And it was for her.
Heechul blinked, his gaze shifting from Donghae’s murderous expression to Hyukjae across the room. He spat a red globule onto the clean floor. His smile returned, blood-smeared and insane. “Remarkable,” he coughed. “The protective impulse. A data point of its own.”
Donghae shoved him away in disgust. Heechul stumbled, catching himself on the edge of a table.
“The base formula,” Donghae demanded, his chest heaving. “The reversal agent. Now.”
“It’s not that simple,” Heechul said, wiping his mouth with the back of his hand. “The recurrence proves instability. A temporary reversal is possible, yes. But permanence?” He shook his head. “The matrix is remembering. Each shift strengthens the feminine template. Forcing a permanent reversion now… could cause systemic collapse. Cellular breakdown. You’d be risking total biological failure.”
The term hung in the chemically-thick air. Total biological failure. Hyukjae understood the euphemism. Death.
Silence descended, heavy and final. The hum of the refrigeration units was the only sound.
“Get out,” Donghae said, the words devoid of all heat, cold and absolute. “We’re leaving. You have one week. One week to find a safe, permanent solution. Or everything you’ve built here disappears.”
He turned his back on Heechul, a monumental act of dismissal, and walked toward Hyukjae. He didn’t touch her. He just stood beside her, a solid wall of quiet fury, waiting.
Hyukjae looked at Heechul one last time. The professor watched them, his eyes no longer just curious. There was a new respect there, and a deep, unsettling caution. She turned and walked out, Donghae at her heels, leaving the lab and its rotting-flower stench behind.
They didn’t speak on the journey back. The train was crowded, pressing them together. Hyukjae felt every point of contact—his arm against hers, his thigh beside her own. Heechul’s words echoed in her skull. Sexual climax with a male partner. A directive. The body craving completion.
Back in Donghae’s apartment, the door clicked shut, sealing them in a silence louder than any scream. Donghae leaned back against it, his head thudding against the wood, eyes closed. The adrenaline was draining, leaving behind a profound exhaustion.
Hyukjae stood in the centre of the room, the hoodie suddenly suffocating. She yanked it over her head, letting it fall to the floor. She stood there in just a pair of Donghae’s loose boxers and a thin tank top, her new body exposed in the grey afternoon light filtering through the blinds.
“So that’s it,” she said, her voice flat. “Every time you fuck me, I turn into this. A factory reset to girl.” She let out a sharp, brittle laugh. “Compatible form. Is that what I am now? Compatible?”
Donghae opened his eyes. The fury from the lab was gone, replaced by a deep, aching sorrow. “Don’t.”
“Don’t what? Say it? It’s the truth. You fuck me, I become her. A convenient little puzzle for Heechul.” She paced, a restless energy possessing her. “Maybe he’s right. Maybe we should test it. Get a control group. See if it’s just you, or if any cock will do the trick.”
“Stop it.” Donghae pushed off the door.
“Why? It’s science!” she shouted, whirling on him. Her eyes were blazing, wet with unshed tears. “Let’s be thorough! Let’s get the fucking rugby team in here and see if they can screw me back to normal! Maybe if enough of them run a train, I’ll just evaporate into pure, stable energy!”
He was in front of her before she could blink, his hands gripping her shoulders. “I said stop!” His shout shook the room. He shook her once, hard. “Don’t you dare. Don’t you fucking dare cheapen this. What happened last night… what happened this morning on the floor… that wasn’t a fucking science experiment. That was me. That was you. That was us.”
“And look what it did!” she screamed back, shoving at his chest. It was like shoving a mountain. “Look at me! This is the ‘us’ you get! A fucking shapeshifter! A problem!”
“You are not a problem!” He released her shoulders only to frame her face with his hands, forcing her to look at him. “You are the solution to every problem I’ve ever had. You’re the only thing in my life that’s ever made sense. I don’t care what shape you come in. I care that it’s you inside.”
“You shouldn’t!” she sobbed, the fight collapsing into sheer despair. “You should want the original model! The one you fell for! Not this… this broken update!”
He kissed her. It wasn’t gentle. It was a claim, a punctuation mark on his words. His mouth was desperate and demanding, swallowing her sobs, her protests, her fear. She clawed at his back, pulling him closer, kissing him back with equal parts fury and need. It was a battle and a surrender all at once.
He walked her backward, never breaking the kiss, until her knees hit the edge of the sofa. She fell back onto the cushions, pulling him down on top of her. Their movements were frantic, fueled by a storm of emotion—rage, terror, and a devastating, all-consuming want.
Clothes were torn, not removed. Donghae’s shirt gave way with a rip of buttons. Her tank top was yanked over her head. He shoved his own jeans and boxers down just enough to free his erection, already hard and weeping against his stomach. He tore the boxers from her hips, the fabric tearing at the seams.
There was no preamble, no gentle preparation. He was rock-hard, and she was wet, her body already traitorously responding to his touch, to his anger, to his need. He positioned himself at her entrance, his eyes locking with hers. His gaze was dark, possessive, blazing with an intensity that stole the air from her lungs.
“This,” he ground out, his voice rough as gravel, “is me claiming you. Not as an experiment. As mine.”
He drove into her in one brutal, deep thrust.
She cried out, a sharp sound of shock and overwhelming pleasure. The stretch was immediate, breathtaking. He filled her completely, a solid, burning anchor in the chaos of her world. He didn’t wait for her to adjust. He set a punishing rhythm, fucking into her with a raw, desperate power that shook the sofa frame against the wall.
The sound was obscene—the wet slap of skin, their ragged breaths, the creak of protesting springs. Hyukjae wrapped her legs high around his waist, her heels digging into the small of his back, meeting every thrust with a roll of her hips. She was adrift, unmoored, and he was the only thing tethering her to reality.
“Is this cheap?” he growled against her neck, his teeth grazing her pulse point. His thrusts were deep, each one jarring through her core. “Is this a fucking control group?”
“No!” she gasped, her fingers scrambling for purchase on his sweat-slicked back.
“Who do you belong to?” he demanded, pounding into her, his cock hitting a spot that made her vision blur.
“You!” she screamed, the word torn from her soul.
He shifted, hooking her legs over his shoulders, opening her wider, penetrating her even deeper. The new angle was ruthless. She clawed at the couch cushions, her back arching off the seat.
“Say it
She clawed at the couch cushions, her back arching off the seat.
“Say it.” His voice was gravel, his thrusts a brutal punctuation. “Again.”
“I’m yours!” The confession ripped from her throat, raw and true, as he pistoned into her. Each drive of his cock was a searing claim. “Donghae, fuck, I’m yours!”
Her climax slammed into her with violent suddenness. It wasn’t a wave but a silent, shattering detonation. Her vision whited out, her mouth a wide, soundless ‘O’ as her cunt clamped down around him in rhythmic, milking spasms. The pleasure was so intense it bordered on pain, a blinding full-body current that erased every thought, every fear, leaving only his name imprinted on her synapses.
He followed with a choked, guttural shout, burying himself to the hilt. She felt the hot, deep pulse of his release inside her, a final claiming. He collapsed atop her, his weight solid and anchoring, his face buried in the sweat-damp hollow of her neck. Their hearts hammered against each other, a frantic, slowing drumbeat in the quiet room.
They lay tangled for a long time, the only sound their ragged breathing syncing into something slower, calmer. The frantic energy that had possessed them both was spent, leaving a spent, tender exhaustion in its wake.
Slowly, gingerly, Donghae pulled out. The slick, wet sound seemed obscenely loud. He shifted to his side, gathering her against him, one hand stroking the damp hair from her forehead. She nestled into the crook of his arm, the aftershocks of pleasure still humming through her veins like a low-grade current.
Then, a familiar warmth bloomed deep in her core. It wasn’t arousal. It was that other feeling, the cellular slide she had come to dread and, in a twisted way, expect. A deep, internal re-knitting.
“Oh,” she whispered, a shiver running through her.
Donghae felt it too. He went very still. His hand, which had been stroking her hair, froze. He looked down at her, his eyes wide in the dim light. She watched the recognition dawn, then a profound, weary sadness.
The change wasn’t violent. It was a soft, whispery sigh of flesh reforming. The subtle strength in her limbs softened. The angles of her face blurred into smoother curves beneath his fingertips. The weight on his arm shifted, becoming lighter, more delicate. The scent of her skin deepened, the subtle musk of sex now layered with a cleaner, floral note.
When it was over, she was Hyuk again. The female Hyuk. The one Heechul’s equations had designed.
Donghae let out a long, shaky breath. He didn’t pull away. Instead, he pulled her closer, tucking her head under his chin. His embrace was protective, resigned.
“See?” she said into his chest, her voice small and thick. “Factory reset.”
He didn’t answer for a minute. He just held her. Then, he kissed the top of her head. “You’re shivering.”
She was. The sweat had cooled on her skin.
“Come on,” he said, his voice soft. He sat up, then scooped her into his arms as if she weighed nothing. He carried her to the bathroom and set her down gently on the closed toilet lid. He ran a warm shower, testing the temperature with his hand.
He helped her in, then stepped in behind her, pulling the curtain closed. The hot water was a balm. He washed her body with a gentle, soapy cloth, his touch clinical and tender all at once, rinsing away the evidence of their fury and their need. He washed himself quickly, then turned off the water.
He wrapped her in a large, clean towel, rubbing her arms briskly before doing the same for himself. Back in the bedroom, he found the oversized hoodie and a fresh pair of his own sweatpants.
“These will swallow you whole,” he said, holding them out.
She looked at the bundle of fabric, then at her own body, so clearly not made for it anymore. The incongruity was a physical ache. “I can’t go out like this.”
“You won’t.” He pulled on a clean t-shirt and jeans. “We’ll fix it.”
“How? With more of Heechul’s magic potions?”
“No.” Donghae ran a hand through his damp hair. “The practical way. First, we get you clothes. Real ones. That fit you now.”
She stared at him. “Shopping.”
“Shopping,” he confirmed, a faint, determined smile touching his lips. “The great equalizer.”
An hour later, they stood outside a small, nondescript boutique in a part of town she rarely visited. The mannequins in the window wore soft sweaters and flowing skirts. Hyukjae felt like an imposter, a ghost in Donghae’s hoodie that hung past her thighs.
“I can’t,” she whispered, her feet rooted to the pavement.
“Yes, you can.” Donghae’s hand found hers, lacing their fingers together. “We walk in. We find things you like. We buy them. It’s just a transaction.”
“It’s an admission.”
“It’s survival,” he corrected gently. “And you’re not doing it alone.”
He pushed the door open, a little bell chiming overhead. The air inside was warm and smelled of vanilla and clean cotton. A saleswoman with a kind face looked up from behind the counter. “Welcome! Let me know if you need any help.”
Donghae led her over to a rack of basic jeans. “Start with necessities,” he said, his voice low. “Jeans. A couple tops. Practical stuff.”
Hyukjae’s fingers brushed against the denim. It felt foreign. She pulled a pair off the rack, holding it up. The cut was clearly for a woman’s hips. A hollow laugh escaped her. “I have no idea what size I am.”
“We’ll guess.” Donghae took the jeans, looking at the tag. He frowned, then scanned the store. He grabbed a soft grey t-shirt and a simple black v-neck sweater. “Try these. The fitting room is over there.”
The fitting room was a tiny, mirrored cube. Hyukjae locked the door and stared at her reflection. The person looking back was a stranger with familiar, haunted eyes. She stripped off Donghae’s hoodie and sweatpants, standing naked under the harsh lights. Her body was undeniably, irrevocably female.
She pulled on the jeans. They buttoned low on her hips, hugging curves she was still learning. The t-shirt was soft, the fabric draping over her breasts in a way that felt both exposing and oddly right. She put the sweater on over it.
When she stepped out, Donghae was leaning against the wall opposite, scrolling through his phone. He looked up.
He didn’t speak. His breath caught, just slightly. His eyes traveled over her, not with hunger this time, but with a quiet, reverent sort of awe. He swallowed hard.
“Well?” she asked, her voice small. She did a stiff, awkward turn. “Do I look like a girl playing dress-up?”
“You look like you,” he said, his voice rough with emotion. “You just look… comfortable. Like you fit.”
Tears pricked at her eyes. She blinked them back fiercely. “It’s just clothes.”
“It’s not,” he said, pushing off the wall. He stepped closer, his hand brushing the sleeve of the sweater. “It’s armor. It’s you deciding to live in the world as you are right now. However long that is.”
She looked down at the soft grey fabric, then back up at him. “I hate it,” she whispered. “And I love that it fits.”
He nodded, understanding the contradiction perfectly. “Get a few more things. Whatever you like.”
She tried on a few more items—dark skinny jeans, a simple dress that felt too big a step, a few more tops. She settled on the practical: two pairs of jeans, three tops, the sweater, and a packet of underwear from a display rack that she shoved into the pile with flushed cheeks. They were plain cotton, but the cut was undeniable.
At the register, the saleswoman smiled warmly. “Found some lovely pieces?”
“Yes,” Donghae answered for her, pulling out his wallet as Hyukjae stared fixedly at a display of scarves.
The woman folded the clothes into a sleek paper bag. “It’s a great basic collection. Perfect for everyday.”
Everyday. The word echoed in Hyukjae’s mind as they stepped back out onto the street. Donghae carried the bag. The afternoon sun was low and golden. For a moment, holding the bag containing clothes that fit her stolen body, with her best friend—her lover—beside her, the terror receded. It was just a transaction. They were just two people, walking home.
He took her hand again. His grip was warm, sure. “One day at a time,” he said, not looking at her, his gaze on the path ahead.
She squeezed his hand, tight. The bag in his other hand rustled, a tangible promise of a tomorrow she was, for now, reluctantly willing to face.