SD: CH168 - Runes Of Undoing

The corridors of Hogwarts carried a different weight that night. Cho moved quickly, every footfall absorbed by stone, every breath sharpened

The corridors of Hogwarts carried a different weight that night. Cho moved quickly, every footfall absorbed by stone, every breath sharpened by the cold air. Her limbs ached in a strangely satisfying way, her nerves still charged with the remnants of what Harry had done—what he had dared to do.

It hadn’t been a kiss. Nothing that could be written off as impulsive. No clumsy fumbling or whispered flattery. Harry saw her—not as Cedric did, through the lens of admiration or possession—but like she was an equation he’d already solved, and he was just letting her catch up.

There was something different about being touched by someone who didn’t need to ask. Who didn’t plead or prod or coax. Who just offered—knowing she would reach out and take.

And she had taken it.

Cedric never made her feel like that.

Not once.

She turned into the narrower passage leading to Ravenclaw Tower, the one she preferred late at night. Fewer eyes. More air.

As she passed the disused classroom before the stairwell, a hand gripped her arm and yanked her inside.

Instincts long trained from her familial disciplines screamed.

She twisted, slammed the attacker against the wall, her forearm pressing against their throat, wand drawn and pointed squarely between the eyes.

A startled sound broke the tension. Her grip tightened. The figure squirmed, and the sound became a gasp.

"Finite," she snapped.

The shimmer of the Disillusionment Charm fell away, revealing tousled brown hair and wide, furious eyes.

"Cedric?" she breathed.

She released him instantly, wand still at the ready. He stumbled back, coughing and clutching his throat.

"Merlin, Cho," he wheezed. "Are you trying to kill me?"

"You tried to ambush me! What else was I supposed to think?"

"Obviously, it’s me! Who else would—?"

She stepped back, scanning the room. Dust hung thick in the air. Moonlight filtered in, casting long shadows. The classroom had once been theirs. Now, it was just another relic.

She let the silence sit for a moment. "So, can I ask why you were creeping around like some rejected villain?"

He scowled. "I saw you. In the library."

"Yes," she said coolly. "Working. With Harry Potter."

"Is that what we’re calling it now?"

She raised an eyebrow. "Cedric, are you seriously doing this?"

"You were flushed. Laughing. His hand—"

"—was tracing a dual-aspect rune pattern."

"Don’t play dumb."

"And don’t project your insecurities onto me," she shot back. "Professor Babbling assigned me to oversee Potter’s project. Something about his rune matrices being unprecedented, apparently."

"You didn’t refuse."

"Why would I?"

She paused, just long enough.

"Because I’m curious. Because I like knowing how things work. And because Potter’s sudden leap in magical ability is suspicious."

He stared at her. "So... you’re spying on him?"

"Spying is such a dramatic word." She stepped closer, her tone lowering. "I prefer 'investigating.' I’m not going to figure out how he ticks by staring from across the Hall. So yes. I’m playing into his little schoolboy fantasy. Letting him think he’s leading the dance."

"He had a crush on you."

"Still does. Which makes it easier."

Cedric looked stunned. "And you didn’t tell me?"

She placed her hand gently on his cheek, her voice softening. "Because I know you, Cedric. I knew you'd overreact. Like now. And I needed him to believe there was nothing strange about it. If you didn’t look angry or suspicious, he’d have no reason to doubt me."

He leaned into her touch. "You’re doing this for us?"

"Of course. Everything I’ve learned about him—all those tiny shifts in tone, that surge of power, the way people react to him—it’s all building to something. And when it breaks, I want to be there."

"He said something to you?"

"He said I looked like I belonged in the Restricted Section," she said with a smirk. "Said he always wondered what it would be like to talk to me."

Cedric’s frown deepened. "And you encouraged it."

"I endured it. For the sake of finding out what he’s hiding."

His shoulders eased slightly. "You’re incredible."

She gave him a tight smile. "I know. Which is why I’m wondering why you thought tailing me under a Disillusionment Charm was a good idea."

He flushed. "I panicked."

"Then maybe think about that. About why your first instinct was to assume the worst."

He reached for her hand. She let him take it.

"I’m sorry," he murmured.

She squeezed his fingers, then let go.

"Let me do this, Cedric. Let me figure out what Harry’s building toward. Because if I’m right, it won’t just change Hogwarts—it’ll change everything. And fetch me a really nice addition to my resume. So, I’d like you to shove your insecurities elsewhere and let this Ravenclaw do what she does best.”

He nodded.

Cho left him in the room, the dust curling in her wake, the moonlight fading behind her. Her expression didn’t waver until she was safely alone.

So easy.

So very easy.

One hand on the heart. One push on the pride. And the Hufflepuff folded right back into place.

She didn’t know if she wanted Harry, or if she just wanted what Harry offered: clarity, power, momentum.

But Cedric? He was no longer in her way.

....

....

Cho Chang wasn’t nervous.

She told herself that twice as she smoothed her uniform skirt, straightened her posture, and stepped into the quiet study room tucked behind the Ancient Runes hall. No one ever came here this late—not even the most overzealous Ravenclaws. Except Harry. And tonight, her.

She shut the door softly behind her, letting the hum of enchantments settle. Her satchel was heavy with her notes—real ones this time. She’d written out everything in detail. Rune charts. Fate-binding correlations. Algiz stabilizers. The theory had to be sound. Harry wouldn’t respect her otherwise.

He looked up as she entered. No smile, but his eyes flicked to her hands, then her collar, then back to her eyes. Calculated. Calm. He sat with a parchment in front of him, his sleeves rolled back, exposing forearms covered in ink stains and rune-ash.

“Chang,” he said, nodding.

“Potter.”

She dropped her bag beside him and slid into the seat, ignoring the hum that settled in her skin as soon as their shoulders aligned. She didn’t let herself shiver, though she wanted to. Instead, she spread out her notes like a shield between them.

“I’ve been thinking,” she said, keeping her tone crisp. “About the matrix.”

Harry’s pen stilled. “Go on.”

“Your theory holds for structured rituals, but I wanted to try something smaller. A test case. Still a system. Still cause and effect. But… less complex.”

He turned to her fully now, elbows on the table, eyes sharp. “Such as?”

She tapped the parchment and muttered something under her breath. Instantly, a familiar rune matrix appeared on it. Perthro anchoring at four corners. Algiz interwoven. 

She reached into her bag and pulled out a folded strip of deep navy fabric. It was silk, charmed to be stain-resistant—a piece from one of her old formal robes. She laid it between them.

“Silk,” she said. “Can easily be cut in any direction with the standard cutting charm. But say, if we wanted the cut to happen… say, along a specific axis, every time we cast the spell…”

“Decreasing randomness….” he murmured — 

“Enacting a predetermined future,” Cho finished quickly. “Granted, it’s far too simplistic, but —”

“The theory would still hold,” said Harry, nodding his head. “How do we do this?”

She drew her wand and aligned the silk on the rune-marked cutting board. Harry leaned in, watching her movements as she traced a clean path along the vertical axis.

“Diffindo,” she said.

The charm hissed sharply. The silk parted down the rune-line in a single, seamless slice—not a thread out of place.

Harry raised an eyebrow. “Controlled. Consistent. But still dependent on direct casting.”

Cho nodded. “Exactly. Predictable... but manual.”

“Not very useful,” Harry mused. “You had to trace the exact pattern beforehand. In any practical system, you wouldn’t get this… intimate with the ritual. Unless you're doing it yourself, it’s practically redundant.”

Cho didn’t argue. He had a point.

“What if…” he said, narrowing his eyes, “I just used intent—and let that trigger the rune scheme?”

“No physical contact?” Cho asked, intrigued. “Worth testing.”

Harry pointed his wand just a foot from the cloth. “Diffindo.”

SNAP.

The fabric didn’t cut.

It exploded.

Tiny, frayed shreds burst outward in every direction like confetti. The air filled with the rustle of silk flutters as slivers settled across the room—on their notes, their robes, even in Cho’s hair.

Harry blinked. “Huh. Didn’t see that coming.”

Neither did Cho.

Nothing in their calculations—nothing in the predictive schema—had suggested this outcome. Diffindo was a clean-line severing charm. Reliable. Predictable. And yet, this had behaved like a cross between Diffindo and Bombarda—if such a hybrid could even exist.

A minima version, maybe?

No. She had seen him. He had spoken the incantation clearly. His wand movements were precise. There had been no deviation.

Then what?

Her eyes flicked back to the parchment, to the glowing matrix still humming faintly.

It must have been the rune.

Had to be.

“That went well,” said Harry. “Alright, what do we have next?”

Cho blinked, and then realised her real plan for tonight. Harry’s actions had unwittingly opened up a new way to get things moving along nicely, without her coming off as too bold.

“Um, I did try being a little creative earlier with the matrix,” she said. “See this glyph overlay?” She pointed at the center of the rune inscription. “I added an auxiliary path into the matrix. It doesn’t need the hex cast directly. The matrix channels the cutting hex through this pre-written structure, and activates it with a whisper." 

Harry leaned closer, studying it. "You embedded the hex itself into the matrix?"

"Exactly," Cho said, pleased. "I wanted it to feel more like fate acting through us. We employ different stimuli to channel intent through the rune—and the hex executes perfectly, but only where we want it to.”

“I slice as I speak?” said Harry, amused.

Cho blushed. “The rune has enough magic to tear the cloth in a straight line. But our whisper — carrying our intent — will decide where the tearing must happen.”

“Our whisper…” repeated Harry.

“Ravenclaw dorm rooms aren’t exactly the most private areas,” she admitted, giving her best shy expression. “Whispers are better than uttering things aloud, and I didn’t want more curious eyes on this.”

“Alright, but we don’t have any cloth left,” Harry pointed out. “Perhaps we can summon —”

“From where?” Cho demanded. “My dorm? Or yours? Wouldn’t it look suspicious if our clothes started flying out of our rooms? Might give people the wrong idea.”

Harry laughed. “You might be right about that. So… conjuring?”

“And risk the conjuration magic interfering with the experiment?”

“No then.”

“Well…” she trailed off, blushing. “We could use our own clothes. I mean, it’s just… a cutting hex, nothing else. We inscribe the inscription on different parts of our robes, and calibrate it to different trigger points, and different stimuli. See if Fate decides its path.”

Harry rolled his wand between his fingers. “You realise we’re basically attempting to use probability as a fabric to alter an object’s physical constitution?”

“Probability was always there,” Cho countered. “We’re only consciously manipulating it.”

Harry grinned, something darkly amused flickering in his gaze. "Which means our clothes will unravel exactly how fate wants them to."

"Not fate," she corrected. "Us. We are the ones writing fate tonight."

They set up quickly. A low hum of magic thickened the air as they re-anchored the ritual matrix onto their robes. Cho worked meticulously, brushing runes along her own sleeves and collar, silently uttering trigger points as she wove them through the Algiz arc.

Harry mirrored her, equally methodical. The flick of his wand, the way his lips moved over syllables—so sure, so easy.

When they were done, he raised his eyes. "Ready?"

She nodded. "Choose your trigger."

Harry stepped forward, closing the distance between them. Cho could feel his breath against the hollow of her throat.

“Here,” he whispered.

Cho shivered.

A narrow incision appeared between her collar buttons, leaving the rest of her shirt untouched.

Cho smiled. “My turn.”

She stepped behind him, fingers ghosting over his wrist. The rune flared faintly under her touch as she dragged her hand up his forearm, across the bicep, over the shoulder—and then down the other side. A perfect arc of intent.

The matrix shivered.

A sound like paper tearing whispered through the air. The shirt split down the upper back and arms—clean, precise, inevitable. A breath later, it fell.

Cho caught her breath.

His shirt dropped to the floor in two halves, leaving his back bare to the light. No fanfare. No dramatics. Just the quiet finality of something undone exactly as it had been designed to be.

Her eyes traced the lean muscles flexing beneath his skin. Harry wasn’t built like Cedric — who carried his physique like a trophy. He was something else — lean, coiled, honed by purpose rather than vanity. A swimmer’s form, maybe. A predator’s stillness. She let her palm press flat against the middle of his back, feeling the heat radiating from him.

It felt like touching a secret.

Like pressing her fingers against a future no one else had seen yet.

“If all you wanted was a free show, you could’ve just asked, you know,” said Harry, amused and turning around. 

“It isn’t like that,” said Cho, blushing and stepping back, taking his entire form into account. This time, her eyes went to the scar on his upper arm. She traced its outline and lifted an eyebrow.

“Basilisk fang,” he said. “From the Chamber of Secrets back in second year.”

Cho’s jaw fell open. The rumors were true? “An… an actual basilisk?”

“And a ruddy big thing it was too,” said Harry, chuckling. “Easily sixty feet or more. I’ll get to know its exact dimensions after Gringotts sends those bloody harvesters.”

Cho blinked again. She had, of course, heard of the private auction of basilisk parts that the Ministry of Magic had set up, only to be put on temporary hiatus. 

“Apparently the Ministry wants the harvesting to happen after the other schools come here and the Triwizard tournament begins. I swear our Minister is an attention whore.”

Cho laughed uneasily, feeling so very small and out-of-place. Something she had little experience with. Instead, she focussed her attention on the other marks on his body, wondering what other secrets they were hiding.

“Ah, that one,” said Harry, as she touched the hollow of his throat, finding thin blackened marks that looked eerily like someone’s fingers. “Burns from the time Professor Quirrel tried to strangle me.”

Cho had heard stories about his Unforgivables class with Professor Moody, where he had shared a little about his struggle against Quirrel. Since the Headmaster, the DMLE director, and other members were present there, she saw little worth in doubting his word.

“It’s like you and I live in very different worlds, you know,” she whispered.

“I can give you a tour of mine, if you want,” he quipped.

Briefly, Cho considered taking him on his offer, before stepping back. “Your turn. What stimulus will you use next?”

Harry arched his brow. “Well, it’s obvious that voice and physical touch work perfectly as stimuli. I’m more interested in seeing if the intent can change the nature of the spell itself.”

“Oh, how?”

“Well, we’ve seen that the spell cuts at the point of stimulation. But what if there are more than one at different points simultaneously?” 

“...Interesting. Go ahead.”

Harry stepped closer. Cho inhaled his cologne. It made her loins stir.

His hands came close to her bosom, barely an inch away, but still refraining from touching. “May I?”

“It’s all for research, isn’t it?”

His lips twisted into a smirk. “Absolutely.”

“Hmm. Go on then.”

He cupped both of her breasts above her shirt, and Cho couldn’t suppress the moan erupting out of her throat at his touch. Just what was it that he did to her? Merlin, she had been Cedric’s girlfriend over the past year and had dated before that, so she was no stranger to the pleasures of flesh, but this… this was something else.

It was like every place he touched, or even breathed, somehow turned into an erogenous zone.

“Rip,” he said.

The inscription activated right away, causing perfectly-cut circles along Cho’s bosom, revealing her vivid teal brassiere. It was a sharp contrast with the reddening that was slowly climbing up her neck and cheeks. Much to his surprise, she pulled the now torn shirt and sat in just her bra and skirt.

“Well, obviously I wasn’t going to sit wearing that,” she sniffed. That he could still see her bra and the bosom it did little to hide, only better than before — was conveniently forgotten. Her instincts screamed at her to conjure something — a blanket, a shirt, anything to hide herself from his eyes, to do something.

Anything.

She didn’t.

Instead, she met his gaze calmly, marvelling at his audacity as he touched her collarbone with a finger, before it moved —lower, slower—dragging warmth in their wake like ink spilled across skin.

Her breath hitched. She felt her pulse stutter beneath his touch and hated how easy it was for him to do this to her. How natural it felt to stand there and let him.

He didn’t touch her like Cedric did—cautious, reverent, always asking. Harry touched her like he already knew the answer. Like the question was just a formality.

She tilted her chin up slightly, letting him look, letting him see. After all, she’d spent years perfecting that very image.

She’d always known what she looked like. The careful polish of her Ravenclaw uniform, the way her skirt skimmed along the upper curve of her thighs. The soft taper of her waist, elegant and firm from years of broomwork. Her chest—not overly full, but high, sculpted, poised. A kind of elegance that didn’t bounce or beg—it commanded.

She wasn’t curvy like Lavender Brown or coltish like Padma Patil.

No.

Cho was all symmetry. Clean lines. The kind of beauty that made you sit straighter. Speak slower. Look twice.  Her beauty wasn’t ornamental—it was weaponized. Deliberate. Contained. Skin smooth as white jade, hair a silken river of black velvet falling down her spine. Her eyes—almond-shaped, cold and exact—rarely gave anything away. They didn’t need to. Her smile did all the cutting.

She knew what she looked like. What they whispered when they thought she couldn’t hear.

Elegant. Exotic. Untouchable.

And yet here she was—breath shallow, eyes fluttering—as Potter of all people unfastened her like parchment beneath a sealing charm.

She let out a slow breath.

His hand brushed just beneath the swell of one breast—chaste in its technique, but electric in its consequence—and she felt her body respond before she could tell it not to.

Her nipples, hard enough to cut something, brushed against the cooled air. The spike of pleasure rushing through her body made it impossible to deny it anymore.

Looking at him, her entire body thrummed with need, and she admired the sight. Harry had never looked more attractive, his handsome face exuding masculine sexual need, an appealing sight for the undersexed fifth-year. That she was getting a reaction like this despite him having his pants on somehow made it better and worse. 

She had been bred on restraint. But he was making it impossible to remember why. And in that moment of insanity, she did something unexpected.

She kissed him.

Reaching for the back of his head, she pulled him roughly, her open mouth reaching his.

As if meant to do so, their mouths formed a tight seal as soon as they met, and just as quickly, their tongues were all over each other. Duelling, swirling around each other, mashed together, exchanging spit. Lips pressed against lips, cheeks hollowed, this was anything but romantic. This was crazed, hungry, animalistic lust, two lovers feeding off each other. Just a few weeks before, Harry Potter was someone to dismiss, and now, her tongue was down his throat, and he was giving her as good as he was getting.

She kissed him till her lungs were burning for oxygen, separating with a heated grasp, and yet she retained her hold over his neck, uncaring that her breasts were smashed against his ripped chest. 

“Chang,” Harry whispered. “All this has been fun, but before we get past this, I want you to think deep and hard about what you’re doing. About Cedric.”

Cho’s blood rang hot with indignation. She wanted to have only one thing ‘deep and hard’ and Cedric was nowhere close to that thought. 

“What about him?” She half-sneered, half-snarled.

“He’s your boyfriend, you’ve been together for a year and more.”

“Didn’t stop you from fingering me earlier at the library,” she spat, folding her hands back beneath her tits. Harry nodded with a ‘well, you got me there’ kind of expression before she continued, “As for Diggory, he obviously has better things to do. Like wallow in self-pity, or cry at the injustice of it all, while making a mockery of himself and everything he stands for.”

“And you decided to dump him for me?”

“I decided to be my own person,” said Cho, scowling. “I’m not Cedric’s trophy, nor someone sitting around, waiting for him to return home victorious, so that I might bask in his reflection.”

She really didn’t understand Harry Potter. He had agreed to let her partner him in his project, knowing the underlying risks. No doubt he had been supremely confident that he had nothing to fear, or even worse, that he had nothing to fear her risking his secret plan of rigging the tournament in his favour. He had read her blatant invitation right, and certainly had no qualms in pushing things down that lane.

And now… after all this… 

“He’s really pissed you off, hasn’t he?”

Cho gave him a very unfriendly smile in acknowledgment.

Nodding, Harry ran his eyes up and down her body with complete approval. “I’ll tell you this though, Chang. Once you get in with me, you might never get out of this rabbit hole.”

His finger dipped to her navel, and rested on the waistband of her skirt, where the last of her uniform’s structure clung to the illusion of propriety.

It would’ve been so easy to stop him. To swat his hand away. Say a word. Shift her weight. Refuse.

But she didn’t.

“What I do… it isn’t just pleasure. Or pain. It’s a rabbit hole so deep down, that before you know it, I will own you.”

Her stomach fluttered under his touch. Not in nervousness—no, she didn’t get nervous.

Anticipation.

Because she wanted to see if he’d keep going. Wanted to know how far he’d push. Wanted to know if her carefully crafted balance—perfect student, dutiful girlfriend, ever-collected Cho Chang—could survive being undone by the boy who now was about to have his way with her.

She had always carried herself with an air that said: you may look, but not touch. Her legs were long, strong from years of flying, tapering to elegant knees and dancer’s calves. Her thighs were shaped more by discipline than indulgence—toned, not soft, with just enough curve to suggest she wasn’t untouched by vanity.

“Show me.”