AUTHOR'S NOTE:
This chapter contains depictions of pranks involving food tampering and physical discomfort. The author does not condone tampering with food or products in real life.
*****
Clap. Clap. Clap.
The slow clap echoed off the stone walls before either of them spotted him.
Fred Weasley was leaning against the far wall with his arms crossed, his Slytherin tie loosened, watching them with an expression that didn't quite reach amusement and didn't quite reach anything else either. George stood half a step behind him, quieter, his eyes moving between Harry and Iris with something more careful in them. A Ravenclaw badge sat neatly on his chest — the one tidy thing about either of them.
"Well, well, well." Fred tilted his head. "Lookie here, Forge. Firsties making trouble." The corner of his mouth pulled up, slow and deliberate. "Proper trouble."
The word landed differently than the rest of the sentence. Proper. Like there was a distinction he was drawing, and they had just crossed to the right side of it.
Harry and Iris went very still in the way that people went still when they were rapidly recalculating. They exchanged a glance, the wordless, compressed kind that only existed between people who had been finishing each other's sentences since before they could properly form them.
They had been so careful. And yet.
"How long have you been standing there," Harry said. Not a question. An assessment.
"Long enough," Fred said pleasantly, "to know what a ghost pepper is." His eyes slid to Iris with something that might have been appreciation. "Or at least, long enough to want to."
George hadn't moved from his half-step behind, but his expression had shifted into something thoughtful. "We heard there was an incident," he said, his tone more measured than his brother's, the kind of measured that came from someone who was doing actual calculation behind his eyes. "Glitter. Pepper spray. Three terrified fifth years. Two Hufflepuffs in the hospital wing." A pause. "We wanted to see what kind of first year carries that sort of thing in their bag."
Iris's chin lifted slightly. "The prepared kind."
"Clearly," George said, and almost smiled.
Fred pushed off the wall and took a few unhurried steps toward them, and Harry had the distinct impression of watching something large and patient decide to move. He understood now why people would go pale at the mention of Weasley's name in the common room (Percy included). Fred didn't move like a third year. He moved like someone who had already decided how every conversation was going to end.
He stopped at a comfortable distance. Close enough to talk. Far enough to be polite about it, which somehow made it worse.
"Here's the thing, little Potter," Fred said, his voice dropping the theatrical lilt and becoming something quieter and considerably more direct. "Vaisey and his lot are in my common room. Have been all year. And they've been a particular kind of irritating." Something passed across his face — brief, cold, and entirely unlike the easy smile that had preceded it. "I have my own reasons to want them handled."
Harry looked at him steadily. "And?"
"And," Fred said, the smile returning at half-wattage, "I heard the words ghost pepper and industrial glitter and thought to myself — these are people worth knowing." He glanced between them. "So. What exactly are you planning? And more importantly..." his eyes settled on Harry with an attention that felt almost physical, "...what does it cost to be involved?"
Harry held his gaze for a moment. Then, slowly, the corner of his own mouth moved.
Because Fred Weasley had just spoken the only language Harry had fully trusted since arriving at Hogwarts.
Nothing for free. Everything has a price. Name it.
"That," Harry said quietly, "depends on what you're bringing to the table."
Fred's smile finally reached his eyes. It was not, Harry noted, a particularly comfortable thing to look at directly.
George, still half a step behind, glanced between the three of them and said, to no one in particular, "I'd like the record to show that I came here about ghost peppers,...."
Nobody listened to him.
******
Day One
The first sign that something was wrong was subtle enough that nobody caught it.
Zabini emerged from the bathroom at half past six looking immaculate as always, sat down on his bed, and began combing his hair with the focused attention he gave everything involving his appearance. It was only when Theo Nott glanced over and did a very slow double take that anyone noticed.
"Zabini," Theo said carefully. "Your hair."
"What about it?"
"It's... moving."
Blaise's hand froze mid-stroke. He looked down at the comb. Then, very slowly, he looked in the mirror above his bedside table.
His hair, which had begun the morning in its usual neat arrangement, was doing something that hair was not supposed to do. Each strand was moving independently, curling and uncurling at its own pace, like something that had recently been informed it was alive and was still deciding how it felt about that.
Blaise put the comb down with extraordinary calm.
"I see," he said.
He did not say anything else. He simply sat very still on the edge of his bed with the expression of a person who was filing something away for future reference.
Then Draco came out of the bathroom.
He had a towel around his shoulders and was rubbing his wet hair with the brisk efficiency of someone with a strict morning schedule to maintain. He sat at his own mirror, glanced at his reflection, and continued toweling his hair dry.
"Has anyone seen my—" he began.
"Draco," said Theo.
"What?"
"Stop rubbing your hair."
"Why?"
Theo opened his mouth. Closed it. Seemed to decide that some things were better witnessed than explained. "Just — stop."
Draco lowered the towel.
In the mirror, his reflection stared back at him. His hair, normally a precise platinum blond, had taken on a distinctly pinkish quality at the roots.
"That's," Draco said, "not right."
"Don't touch it," Theo said immediately.
Draco touched it.
"DRACO—"
"MY HAIR—"
"I told you—"
"WHAT IS HAPPENING TO MY HAIR—"
"The more you rub it the redder it's becoming," Theo said, with the resigned tone of someone watching an inevitable disaster complete itself. "You could be the other Weasley sibling."
The shriek that followed woke the rest of the dormitory.
By the time the Slytherin table filed into the Great Hall for breakfast, the damage was fully visible in the unforgiving morning light.
The other houses noticed immediately.
The Gryffindor table went first — a ripple of poorly suppressed laughter starting at the far end and rolling steadily toward the staff table like a wave gathering momentum. The Ravenclaws were more restrained but no less entertained, several of them leaning together in quiet observation with the expressions of people cataloguing something genuinely interesting. Even the Hufflepuffs, who were constitutionally inclined toward kindness, were struggling.
Draco Weasley — as he would be referred to in whispers for approximately the next week — sat down with the rigid dignity of someone pretending nothing was happening. The deep red had settled into his hair with absolute commitment. No amount of Madam Pomfrey's suggested remedies, attempted during a very brief and very embarrassing pre-breakfast visit, had shifted it even slightly.
He was not alone in his suffering. The fifth-year prefect had somehow acquired a magnificent silver streak running ear to ear. Two third year girls were now matching shades of violet. A seventh-year boy who had arrived at Hogwarts with fine straight hair was navigating the Great Hall with an impressive afro that added four inches to his height and had briefly caused him to get stuck in the dormitory doorway.
He had looked in the mirror for a long time before breakfast.
He was still deciding how he felt about it.
The Slytherin table sat in collective mortification, staring at their porridge with the focused intensity of people pretending to be somewhere else entirely.
"It wasn't me," Fred said loudly, for the third time, to no one in particular.
"Fred." Percy's voice came from two seats down, flat with the specific exhaustion of someone whose patience had been load-bearing for years and was beginning to show structural damage.
"Percy, I swear on Mum's good china—"
"Fred."
"I didn't even know shampoo could do that—"
"FRED."
"—and if I had known I would have absolutely used it sooner, obviously, but the point is I didn't—"
Percy put his fork down with a precise, controlled movement that was somehow louder than if he'd slammed it. "I am going to ask you once. Did you or did you not—"
"It wasn't him."
The voice was quiet. Matter of fact. Coming from approximately three seats further down where George Weasley was buttering his toast with an air of complete serenity.
Percy turned slowly. "George."
"It genuinely wasn't him," George said, not looking up. "I would know."
"That is not the reassurance you think it is," Percy said.
George considered this. "No," he agreed pleasantly. "I suppose it isn't."
Day Two
"AHHHHHHHHHH!!!!!"
"What the bloody hell??"
"Ew! Ew! Ew!"
Harry had been awake since four thirty. He pulled his curtain back one careful inch and watched Burke, who had shoved his feet directly into his shoes without checking them first, freeze mid-step with an expression that moved through confusion, comprehension, and pure horror in approximately half a second.
He let the curtain fall.
The screaming continued.
From what Harry could piece together from the sounds alone, the slime had appeared sometime in the night. It coated the stone floor in a thin, deceptively invisible layer that only became apparent when someone stepped on it in socked feet. It was on the chair cushions. It was on door handles. Someone — and the resulting shriek suggested it was Nott — had reached into their school bag for their Transfiguration textbook and retrieved instead a handful of something green and deeply unpleasant.
"My wand," someone said, in the voice of a person discovering a personal tragedy. "It's on my wand—"
"Don't touch the—"
"It's inside my shoe—"
"How is it inside the shoe—"
"HOW IS IT ON THE CEILING—"
Harry blinked. He hadn't planned for the ceiling.
Sure enough. The common room's vaulted stone ceiling, dimly lit by the greenish glow filtering through the lake windows, had acquired a collection of slowly dripping stalactites of slime, each one hanging with a kind of patient, architectural commitment.
Harry stared at it.
He was going to have to ask Iris how she had managed the ceiling.
Blaise appeared at Harry's shoulder, having navigated the floor with the careful precision of a man crossing a minefield. He looked up at the ceiling. He looked at Harry. He looked back at the ceiling.
"The ceiling, Potter," he said.
"I see it," Harry said.
"She did the ceiling."
"She is thorough," Harry agreed.
Blaise pressed his lips together. Looked one more time at a particularly ambitious drip making its way toward the prefect's favorite armchair. Then he turned, picked up his school bag — checking it very carefully before opening it — and said, to the room in general and no one in particular, "I'm going to breakfast early."
Nobody stopped him.
In the corridor outside the common room, the slime stopped exactly at the threshold. Not a drop beyond it. Perfectly contained. Surgical, almost.
Harry stepped over it and followed Blaise to breakfast, both of them immaculate, both of them saying nothing, both of them watching the corridor ahead with the focused expressions of people who had absolutely nowhere to be and were going there very calmly.
Behind them, the screaming continued.
Day Three
It started at two in the morning.
One moment the Slytherin dormitories were silent. The next, the stone walls were vibrating.
The sound that erupted from the common room radio was not music. Not by any definition currently recognized by the wizarding world. It was a wall of sound — guitars screaming over each other, drums hammering with the persistence of something that had given up on subtlety entirely, and a vocalist who appeared to be in considerable distress about something and wanted everyone within a considerable radius to know about it.
"WHAT THE—"
"MAKE IT STOP—"
"WHAT IN THE WORLD IS—"
The common room erupted. Students in various states of undress descended the dormitory stairs in a stampede, wands out, hair disheveled, faces carrying the particular outrage of people whose sleep had been interrupted by something they didn't have the vocabulary to describe.
"Turn it off!" Vaisey shouted over the noise, jabbing his wand at the radio.
Nothing happened.
"Silencio!"
"Silencio!"
The music got louder.
The common room went very still for a moment, everyone staring at Vaisey, who was staring at his wand with the expression of a man whose understanding of how magic worked had just been quietly undermined.
He tried again. "Silencio!"
Louder still. The stone walls hummed with it. A first year's stack of textbooks vibrated off the edge of a table.
"Stop casting at it!" someone yelled.
"Then you do something—"
"Finite Incantatem!"
The guitar screamed. Several people covered their ears.
The combined silencing charm from the seventh years didn't just fail — it produced a feedback shriek that sent half the common room stumbling backward. When the sound settled back to its original volume, three people were sitting on the floor looking personally offended by the laws of magic.
"Try unplugging it," someone yelled.
Harry glanced sideways. It was a fifth year he didn't know well — a half-blood named Avery whose reading habits Harry had noticed leaned toward Muggle paperbacks kept inside transfigured textbook covers.
"What?!" someone nearby asked.
Avery caught himself. "Nothing," he said, rearranging his expression into one of appropriate bafflement. "I have no idea what any of this is."
Harry looked at him.
Avery looked at Harry.
A small understanding passed between them, the way understandings did in Slytherin — quietly, without being acknowledged, filed away for later.
The music played on.
*****
By morning it had not stopped.
Breakfast at the Slytherin table was a study in collective suffering. Dark circles had appeared under eyes that were usually immaculately presented. Hair that had only just recovered from Day One was now in a secondary state of disarray from hours of tossing in beds that vibrated gently with the bass. Three students had fallen asleep directly into their porridge and nobody had the energy to comment on it.
"Throw it out," Draco said, pinching the bridge of his nose. "Just...physically remove it."
Two fifth years approached the radio with the careful energy of people handling something potentially dangerous. They removed it from the wall. The music continued. They looked at each other. One of them picked it up. The music continued. They carried it out of the common room, down the corridor, and deposited it outside the entrance to the dungeons with a sense of finality.
They returned to the common room.
The radio was already back on the shelf.
Same position. Same cord plugged into the same socket. Same song, which Harry had privately come to think of as the common room's unofficial theme, given how many times it had cycled back to the beginning.
The two fifth years stood in the doorway and looked at it for a very long time.
"That," one of them said finally, "is not possible."
"Put it in the lake," someone suggested.
They tried that too, on day two of the music. It took three of them to manage it, levitating the equipment through the castle in the early hours of the morning, past portraits that pointedly looked the other way, down to the edge of the Black Lake where they deposited it in the shallows with considerable satisfaction.
By the time they returned to the common room, shivering and damp and triumphant, the shelf was occupied again.
Different radio. Same music.
Pansy Parkinson sat down on the common room sofa, pulled a blanket over her head, and didn't come out until breakfast.
Theo Nott, who had approached the problem from a theoretical angle and spent two hours attempting to locate and dismantle the charm work responsible, stopped in the middle of his third diagnostic spell and went very quiet.
"What?" Draco asked.
"I can't find it," Theo said.
"What do you mean you can't find it?"
"I mean," Theo said carefully, "that as far as my spells are concerned, there is no active charm on this radio. There is no enchantment. There is no spell. There is no magical signature attached to this equipment whatsoever." He paused. "The radio is just...playing."
Draco stared at him.
"That," Draco said, "is significantly more alarming than if you'd found something."
Theo nodded slowly. "Yes," he said. "I thought so too."
In his bed, curtains drawn, Harry listened to Theo's diagnostic spell wash harmlessly over the walls of the common room and felt the castle hum very faintly in response, the way it sometimes did when he pressed his hand to the stone and spoke quietly in the language that the portraits and the suits of armor and the old painted snakes in the corridors understood. Not magic, exactly. Just — attention. The castle paying attention.
He had asked it nicely.
It had been happy to help.
Day Four
The Slytherin table at breakfast looked like the aftermath of something.
Dark circles had graduated from noticeable to architectural. Malfoy had acquired a hat from somewhere, a neat, expensive thing that sat slightly too low on his head and did not quite disguise the faint reddish tinge still visible at his ears. Nobody mentioned it. Pansy had her head propped on her hand with the glassy expression of someone whose body had arrived at breakfast but whose mind had filed for a leave of absence. Two sixth years had been caught sleeping in an empty Charms classroom at midnight and had received detention on top of everything else, which had done nothing for the general atmosphere.
Someone had found slime residue in their shoe again. The resulting sound had been less a scream and more a long, exhausted exhale of pure defeat.
Harry ate his eggs methodically, cutting them into precise thirds, and kept his eyes on his plate. Except for the occasional glance. Measured. Spaced far enough apart to look like nothing. Just a first year eating breakfast and occasionally looking around the Great Hall the way anyone might.
Vaisey was three seats down. He was eating porridge with the mechanical energy of someone fueling a body that had stopped cooperating. Hersey beside him. Fawley across. All three of them looked, Harry thought, approximately how he had felt the morning after they'd cornered him outside the common room, which he found mathematically satisfying.
Blaise, seated to Harry's left, noticed the glances. He noticed most things. It was, Harry had come to understand, both Blaise's greatest skill and his primary source of anxiety.
He looked at Harry. Then at the third years. Then back at his own breakfast, which he regarded with sudden deep suspicion.
"I'm not hungry," Blaise announced, to no one in particular.
"You haven't touched your toast," Harry observed.
"I'm aware."
"The toast is fine, Blaise."
"You'll forgive me," Blaise said, with great dignity, "if I've developed trust issues."
Harry said nothing. He took a calm sip of pumpkin juice.
Three seats down, Vaisey reached for the pepper shaker out of habit and seasoned his porridge.
Harry watched.
Hersey did the same.
Fawley, who had been staring into the middle distance with the expression of a person considering early retirement, roused himself enough to follow suit.
Harry looked back at his eggs.
Across the table, Blaise had gone very still. "Potter," he said quietly.
"Mm."
"Did you—"
"Eat your toast, Blaise."
Blaise looked at his toast. Looked at the pepper shaker, which had made its way to his end of the table. Looked at Harry.
He picked up his toast and ate it dry, without touching another condiment for the remainder of breakfast.
*****
The first sign came seven minutes later.
It was, in retrospect, the most warning anyone was going to get.
Vaisey made a sound. Not a scream — not yet. More of a sharp intake of breath, the kind that preceded something more significant. His hand went to his throat.
Hersey looked at him. "You alright?"
Vaisey shook his head, very slightly.
Then Hersey's hand went to his own throat.
Then Fawley sat up very straight.
The screaming started with Vaisey. It spread to Hersey within seconds, and Fawley a moment after that, and the Great Hall, which had been in the comfortable murmur of early morning, went abruptly, completely silent.
Every head turned.
The three third years were on their feet, hands at their mouths, faces cycling rapidly through shades that had no business appearing on human skin. Vaisey grabbed for his water goblet and drank deeply.
It got worse.
"MILK!" someone yelled from the Hufflepuff table, Hannah Abbott, on her feet, already reaching for the jug in front of her with the urgent competence of someone who knew exactly what was happening. "THEY NEED MILK—"
The jug was already moving. Levitated, sailing smoothly over two tables, arriving at the Slytherin table with a precision that suggested the caster had anticipated the need. Harry didn't look up from his eggs.
Vaisey seized the jug. Drank. The screaming subsided into something more like desperate whimpering. Hersey grabbed it next. Then Fawley.
The Great Hall watched in collective stunned silence.
Gradually, the whimpering stopped. The three boys stood breathing hard, eyes watering, but upright. Alive. Functional.
"What," said the Ravenclaw prefect slowly, "was that."
The tension broke. Gryffindor went first. Laughter starting low and building fast, the kind that feeds on itself. Hufflepuff followed, several of them looking guilty about it, which only made it funnier. Even some of the Ravenclaws were pressing their hands over their mouths with expressions of pained amusement.
At the staff table, Professor Flitwick had his hands over his mouth. It was unclear whether he was hiding a smile or genuine concern. Probably both.
Professor McGonagall had her lips pressed into a very thin line that was doing a great deal of work.
Professor Snape was looking at the three third years with an expression of cold, measured assessment that had nothing to do with amusement and everything to do with filing information away.
Vaisey, Hersey, and Fawley sat back down with the careful movements of people reassembling their dignity from scattered pieces. Vaisey's jaw was set. His eyes, still watering, moved slowly down the Slytherin table.
They stopped on Harry.
Harry was eating his eggs. He had been eating his eggs. He would continue to eat his eggs. He looked up at exactly the right moment, not too fast, not too slow, met Vaisey's gaze with an expression of mild, polite curiosity, and looked back down.
Vaisey's hands curled slowly around his goblet.
Then Hersey made a sound.
A different sound.
The color drained from his face in a way that had nothing to do with the ghost pepper's initial effect and everything to do with its secondary one.
"I need to—" Hersey started.
He didn't finish the sentence. He didn't need to. The way he stood up, very suddenly, very urgently, communicated everything the sentence would have.
He made it approximately four steps before the Great Hall understood what was happening.
The laughter that followed was of a different quality entirely. Less the bright hilarity of a moment ago and more the kind that people felt slightly bad about even as they couldn't stop. Several Hufflepuffs had buried their faces in their hands. One Gryffindor fourth year had slid entirely under the table.
Fawley stood up next, with the same urgent trajectory.
Then Vaisey, who had just enough time to turn and look directly at Harry with an expression of absolute, incandescent understanding before necessity overruled dignity entirely.
The Great Hall watched them go.
The silence that followed was the specific silence of five hundred people deciding simultaneously not to say the thing they were all thinking.
Professor Snape stood up from the staff table.
He did not look at Harry. He looked at the doors through which three of his students had just departed at considerable speed, and his expression was the expression of a man doing calculations.
Harry picked up his toast and took a bite.
*****
Three days earlier.
The Undercroft
The room had found Iris, not the other way around.
"Tada!" Iris said and pushed.
The door appeared from the clock underneath the stairs of the Defense Against the Dark Arts classroom.
The four of them stood at the threshold of a room that smelled of old stone and woodsmoke and something that might have been centuries of secrets. It was large, larger than it had any right to be given the wall it had been hiding behind, with a low vaulted ceiling and a fireplace that lit itself when they entered, as though it had been waiting.
On the far wall, scratched into the stone in a dozen different hands across what looked like decades, were names.
Fred crossed the room in four strides and ran his finger along the wall slowly. "Sebastian Sallow," he read. A pause. "Ominis Gaunt." Another pause, longer. "Thalen Crests." He was quiet for a moment. "Slytherins," he said, with a tone that meant something more than the word itself.
"You know them?" Harry asked.
"Of them," Fred said, and didn't elaborate.
George was already examining the fireplace with the focused attention he gave anything that defied easy explanation. Iris was still standing in the center of the room, turning slowly, reading the magic the way she read everything — patterns, connections, the invisible architecture of how things held together.
"Nobody's been here in a long time," she said.
"Good," Harry said. He set his bag down on the nearest surface. "That's exactly what we need."
It was George who noticed the bag first. Specifically, the particular way it clinked when Iris set it down. "What," he said, "is in there."
"Equipment," Iris said.
"What kind of equipment?"
"The useful kind." She was already opening it. "Now. Fred. Don't touch anything until I've explained what it—"
Fred had already touched something.
Specifically, he had picked up a small, wrinkled, deeply unassuming dried pepper from the open bag and was examining it with the focused curiosity of someone who had never met a thing they weren't willing to immediately investigate.
Harry saw it first. He went very still.
"Fred," Harry said, in the careful voice of someone who had learned to stay calm in emergencies. "Put that down."
"What is it?"
"It's a ghost pepper. Put it down."
"A ghost pepper," Fred repeated, turning it over. "What does it—"
"Fred—"
Fred ate it.
The room went silent.
Iris slowly covered her face with both hands.
George took out a small notebook and a quill with the calm efficiency of a naturalist who had just been presented with a specimen. "For the record," he said, "I want it noted that I had nothing to do with this and I did say—"
Fred made a sound.
It was not a scream, exactly. It was something that preceded a scream — a sharp, total-body realization of what he had just done, moving across his face like weather.
Then it was a scream.
"WATER—" Fred lunged for his bag. "WATER—I NEED—"
"Milk," Harry said, already reaching into Iris's bag with the practiced efficiency of someone who had planned for this exact contingency. He produced a small bottle and held it out. "It has to be milk."
Fred seized it. Drank. The screaming subsided into heavy breathing.
The room was quiet for a moment.
"Right," Fred said, his voice several textures rougher than it had been. His eyes were streaming freely. He wiped them with the back of his hand. Straightened up. Looked at the pepper, which was sitting innocuously on the table where he'd dropped it.
"That," he said, with the reverence of someone who had just met something worthy of respect, "is brilliant."
"You just voluntarily ate something that made you scream," Iris said flatly.
"And now I understand exactly how it works." Fred turned to look at her with an expression that was still forty percent physical suffering and sixty percent genuine delight. "The first thing to know how something works is to test it out. What better way than through experience?"
"You are not going to have a wonderful experience," Harry said. "In approximately..." he checked his watch, "...six to eight hours."
Fred looked at him.
"The initial reaction isn't the worst part," Harry said.
A beat of silence.
"How bad," Fred said slowly, "is the worst part?"
Harry and Iris looked at each other.
"You should probably stay near a bathroom," Iris said, with genuine sympathy, "for the rest of the day."
George had been writing steadily throughout this exchange. He looked up. "I'm documenting this for science," he said, to no one in particular. "Also, Fred, I told you not to touch anything."
"You didn't say anything," Fred said.
"I was thinking it very loudly."
Fred looked back at the pepper. Despite everything — despite the streaming eyes and the rough voice and the dawning comprehension of what the next six to eight hours were going to involve — he was smiling. It was the smile of someone who had just been handed a weapon they hadn't known existed and was already thinking about the possibilities.
"Right," he said. He pulled up a chair, sat down, and looked at Harry across the table with watering eyes and absolute focus. "Tell me everything."
****
The flashback ends there and snaps back to the present. Snape standing, doing his mind calculations, Harry eating his toast — and the contrast between the chaos of the Undercroft scene and Harry's perfect stillness in the Great Hall lands the chapter's core point. He planned all of this. He is completely in control. And Snape knows it, even if he can't prove it yet.
Day Five
Harry had been awake since four again.
This time he was prepared. He had wedged himself carefully against the headboard before falling asleep, his blanket tucked in a specific way that Iris had assured him would account for the reversion. He had not entirely believed her.
He believed her now.
"AHHHHHHHH—"
Harry hung upside down from his bed and looked at the ceiling, which was now the floor, and the floor, which was now the ceiling, with the calm expression of someone who had built this particular contingency into the plan and was mildly pleased to find it working correctly.
Around him, the dormitory had erupted.
Cursing. Specifically, the kind of cursing that happened when someone had been pushed past the point where they cared about vocabulary. Blaise, hanging upside down two beds over, had his arms crossed and was staring at the floor-ceiling with an expression of someone who had moved through shock and outrage and arrived, exhausted, at a place of bleak philosophical acceptance.
"Potter," Blaise said.
"Mm."
"I am hanging upside down from my bed."
"I can see that."
"My blood is rushing to my head."
"That will pass."
A pause. "How do you know."
"Educated guess."
Blaise closed his eyes. "I want you to know," he said, with great dignity, "that I am going to be absolutely furious about this as soon as I am the right way up."
From somewhere down the corridor — past the first year dormitory, past the second years, from the direction of the private prefect rooms that were supposed to be separate, protected, warded with a different set of enchantments entirely — came a sound that was less a scream and more a declaration.
"I AM GOING TO FIND OUT WHO DID THIS AND I AM GOING TO KILL HIM."
The dormitory went very quiet.
Even upside down, everyone recognized the voice. Marcus Flint did not shout. Marcus Flint didn't need to shout. The volume wasn't what made it land the way it did — it was the absolute, load-bearing certainty of someone who meant every syllable and had the physical capability to follow through.
Theo Nott, hanging upside down from his four-poster, turned his head slowly toward Harry with an expression that was the first genuinely suspicious look Harry had received in five days.
Harry was already looking at the ceiling-floor with the serene blankness of someone whose mind was entirely empty of relevant thoughts.
"The prefect rooms," Theo said slowly. "Someone got into the prefect rooms."
"Apparently," Harry said.
"Those are warded separately."
"Are they?"
"You need specific knowledge of the castle's architecture to access them."
"Interesting," Harry said.
Theo stared at him for a long moment. Harry could feel the stare the way you felt weather coming — that pressure of someone doing careful arithmetic in your direction.
"I don't know anything about architecture," Harry said pleasantly.
Theo kept staring.
Down the corridor, something large fell over, followed by Flint's voice again, lower now and therefore worse. "When I find out who is responsible—"
"You won't," said a second voice. Quieter. Vaisey.
A pause.
"What did you say," Flint said.
"I said—" Vaisey stopped. Seemed to reconsider the wisdom of finishing that sentence while hanging upside down in front of Marcus Flint. "I said. We should figure this out together."
A long silence.
"Get down," Flint said finally, to the room at large. "Figure it out. Someone find me a counter charm before I lose circulation in my feet."
*****
Getting down proved more complicated than anticipated.
The reversion charm, it turned out, was not a simple Finite situation. Three different counter charms failed. Someone attempted to physically pull themselves off the bed and succeeded only in dangling at an angle that was worse than vertical. A fourth year tried to summon his wand, which had fallen to the ceiling-floor, and managed to hit himself in the forehead with it.
The solution, eventually, was to get the right way up by going further wrong — a full rotation, arms tucked, dropping to the ceiling-floor and then righting as the charm completed its cycle. Iris had apparently built in a release mechanism. It just required committing to the momentum.
Harry completed the rotation with the ease of someone who had practiced it at four in the morning and landed neatly on his feet.
His dormmates stared at him.
"Fencing," Harry said, adjusting his collar. "It helps with spatial awareness."
Nobody said anything.
He picked up his bag and headed for the door. "Breakfast?"
*****
Flint found him in the corridor outside the Great Hall.
Not cornering him. Just appearing beside him, falling into step with the unhurried weight of someone who didn't need to rush to make a point.
"Potter," Flint said.
"Flint," Harry said.
They walked in silence for a few steps.
"The prefect rooms," Flint said.
"Terrible business," Harry said.
Another silence.
"Someone with knowledge of the castle got in there," Flint said. "Specific knowledge. The kind you don't get from books."
"Mm," Harry said.
"The kind you'd get from—" Flint paused. Seemed to choose his next word carefully. "—unconventional sources."
Harry said nothing.
Flint stopped walking. Harry stopped with him. They stood in the corridor outside the Great Hall with the noise of breakfast filtering through the doors, and Flint looked at him with the same cold, clinical assessment he'd used in the common room entrance weeks ago. The look that didn't ask questions so much as file observations.
"I want to be very clear about something, Potter," Flint said, his voice dropping below the ambient noise of the corridor. "I don't know what's happening in my common room. I don't know who's behind it. I don't have proof of anything." A pause. "But I want you to understand that whatever is happening, it ends before it becomes a problem for the house that I can't manage."
Harry met his gaze. "Understood," he said.
Flint studied him for another moment.
"Vaisey's going to come for you properly," Flint said. "Whatever's been keeping him civil — he's running out of patience. And scared people do stupid things."
"I know," Harry said.
"Good." Flint straightened up. Something shifted in his expression — not warmth, exactly. More like the acknowledgment between two people who understand each other's position. "If something stupid happens," he said, "I didn't see anything."
He walked into the Great Hall.
Harry stood in the corridor for a moment.
Then he followed.
Day Six
It started, as Blaise would later describe it to no one because he refused to speak of it, with a sound.
A soft sound. Almost gentle. The kind of sound that, in another context, might have been described as festive.
Pff.
Blaise opened his eyes.
The Slytherin common room was green. It was always green — the lake light, the banners, the general aesthetic commitment of seven centuries of interior decoration. But it was a different kind of green this morning. A brighter green. A green that caught the light in small, individual, enthusiastic pieces.
Blaise sat up very slowly.
"No," he said.
His voice came out strange. Flat. The voice of a man whose mind had performed an emergency evacuation.
"No," he said again, louder.
Glitter. There was glitter everywhere. On the common room floor. On the furniture. Suspended in the air in lazy, drifting clouds that the dungeon's ambient chill kept aloft with dreamy persistence. It coated the surface of the lake-green windows and fractured the light coming through them into a thousand small, cheerful points that bounced around the room with complete indifference to the suffering they were causing.
It was in his hair.
Blaise touched his hair with one careful hand and looked at his fingers and the small cascade of silver and gold that fell from them.
Something in his expression went very quiet. Very still. The stillness of a person accessing a memory they had filed under things that must never happen again.
*****
"POTTER!" Blaise's voice cracked off the dungeon ceiling and came back at him.
It didn't matter which Potter. It applied to all of them. It applied retroactively to every Potter going back to the founding of the bloodline. It applied, in some philosophical sense he was too sleep deprived and glitter-covered to articulate, to the concept of Potters as a category of being.
Around him, the rest of the common room was waking up to the same discovery in various stages of horror. Someone sneezed and produced a small explosion of silver. A seventh-year prefect walked through a drifting cloud of it and emerged looking like she had been blessed by something that had very poor taste.
Draco Weasley — he had given up fighting the nickname internally even if he would sooner expire than use it aloud — stood in the center of the room in his hat, covered in glitter, and said nothing for a very long time.
"I want to go home," he said finally.
"Same," said approximately seven people.
*****
By nine o'clock, Professor McGonagall had summoned Iris Potter to her office.
Professor Flitwick had come along on the grounds that he had questions. Professor Sprout had come along on the grounds that Iris was her student, and she wasn't going to let the girl face a McGonagall interrogation without her head of house present. The result was a somewhat crowded office and one eleven-year-old girl sitting in a chair across from three professors with her hands folded neatly in her lap and an expression of polite, attentive innocence.
"Miss Potter," McGonagall began.
"Professor," Iris said.
"You are aware of the incidents occurring in the Slytherin common room over the past week."
"Everyone's aware," Iris said. "It's been quite eventful."
McGonagall's eyes narrowed very slightly. "The glitter. Specifically."
"Terrible business," Iris said.
"You have a history," McGonagall said, "of glitter-related incidents."
"I was nine," Iris said. "And I maintain that was a learning experience."
"For whom?"
Iris considered this. "Everyone present," she said diplomatically.
Flitwick made a small sound that might have been a cough.
"Miss Potter." McGonagall folded her hands on the desk. "The Slytherin common room is warded. Students from other houses cannot enter."
"I know," Iris said. "That seems like a very sensible precaution."
"So, you understand why we're curious—"
"I'm a Hufflepuff," Iris said. "I can't get into the Slytherin common room. I couldn't even if I wanted to." She paused. "Which I don't. Obviously."
"Your brother is a Slytherin," McGonagall said.
Iris tilted her head. "I have another in Gryffindor," she said. "What's your point?"
The office was quiet.
Professor Sprout, to her considerable credit, kept her expression entirely neutral. She was, however, looking at a point slightly above McGonagall's head with the focus of someone concentrating very hard on not reacting.
"Miss Potter," McGonagall said, in the tone of someone choosing their next words with surgical precision, "do you know anything about what has been happening in the Slytherin common room?"
Iris met her gaze with the clear, steady eyes of someone who had been raised by Petunia Dursley and had therefore been field-tested against far more formidable interrogators.
"Professor," she said, with great sincerity, "I barely know what's happening in my own common room half the time. The Hufflepuff basement is a very busy place."
Another silence.
"You may go, Miss Potter," McGonagall said.
Iris stood, smoothed her robes, and picked up her bag. At the door she paused. "Should I be worried about my brother?" she asked, and her voice was perfectly calibrated — just enough concern to be sisterly, not enough to be suspicious. "Only, it sounds like someone's been having a terrible time in there and I'd hate for Harry to get caught up in anything."
McGonagall looked at her for a long moment.
"Your brother," she said carefully, "is fine."
"Good," Iris said warmly. "Thank you, Professor."
She closed the door behind her with a soft, definitive click.
In the office, nobody spoke for a moment.
"Well," said Flitwick eventually.
"Don't," said McGonagall.
Sprout was looking at the ceiling. Her shoulders were shaking very slightly.
"Pomona," McGonagall said.
"I'm not doing anything," Sprout said, in a voice that suggested she was doing something.
McGonagall pressed her fingers to her temple. Outside her window, the castle went about its morning with complete indifference to the conversation that had just taken place in her office. Somewhere below, the Slytherin common room was presumably still covered in glitter.
She had a feeling it was going to be a very long week.
Day Seven
The music started again at two fourteen in the morning.
It had been silent for six hours. Long enough that people had started to hope. Long enough that exhausted students had actually fallen into real sleep for the first time in days — deep, unguarded sleep, the kind that made the return of the guitars feel like a physical assault.
The common room lights flickered on automatically with the noise, as they always did, as though the castle had decided that if everyone was going to be awake they might as well be able to see each other suffering.
Draco Weasley — he had stopped correcting people — sat up in bed.
He sat there for a long moment. His red hair, faded now to a stubborn strawberry blond that no charm had fully shifted, was flattened on one side from sleep. There was glitter on his pillow. There was still glitter on his pillow. There would, he had come to understand, always be glitter on his pillow. The glitter had become permanent in the way that trauma became permanent — present even when you couldn't see it, ready to catch the light at the worst possible moment.
The music climbed toward a crescendo.
Something in Draco Malfoy's face went very smooth and very still.
Then he stood up, walked to the center of the dormitory in his pajamas, and said, at a volume that cut cleanly through the music, "ENOUGH."
Nobody moved.
"I said ENOUGH." He turned in a slow circle, addressing the room, the ceiling, the walls, the general principle of the past seven days. "I don't care who is doing this. I don't care why. I don't care about house politics or third year grudges or whatever this is supposed to prove. I want it to STOP and I want to SLEEP and I want the glitter off my pillow and I want my HAIR BACK—" his voice cracked slightly on the last word, which he covered immediately by raising the volume, "—and whoever is responsible I want them to know that I, Draco Malfoy, have had ENOUGH—"
"Malfoy." Harry's voice came from behind his curtain. Quiet. Calm. The specific calm of someone who had been awake for the past hour thinking.
Draco spun toward it. "WHAT, POTTER—"
"Sit down," Harry said, without heat. "All of you. I need to show you something."
A pause. The music wailed on.
Draco sat down. Not because he was told to — Draco Malfoy did not do things because he was told to — but because his legs had made the decision independently, the way legs did after seven days of inadequate sleep.
One by one, curtains opened. Blaise emerged first, unsurprised, as though he'd been waiting. Theo followed, his expression already sharpening into the focused attention he gave things he found genuinely interesting. Burke came out slowly, arms crossed, something careful moving behind his eyes. Zacharias Smith pushed his curtain back without a word and sat on the edge of his bed and watched.
Harry stepped out last. He was fully dressed, which nobody commented on, though Theo's eyes noted it.
"The dormitory wards," Harry said, without preamble. "This room has them. Every dormitory in the castle does — they're old, built into the foundations, part of the original construction. They're not active because nobody's activated them. But they can be."
Silence. Even the music seemed to recede slightly, as though the castle was listening.
"What do they do," Theo said.
"They seal the room," Harry said. "Anyone keyed to the ward can enter freely. Anyone not keyed to it—" he paused, "—can't. And anything that happens inside stays inside. No external interference."
Draco's eyes had sharpened despite the exhaustion. "You mean whatever's been getting into our dormitory, all the pranks, the tampering,"
"Stops," Harry said. "Yes. It also has a silencing charm too which means we won't be able to hear the sound of music outside"
Another silence. Longer this time.
"How do you know about this," Theo said. Not aggressively. Carefully. The voice of someone taking a thing apart to see how it worked.
Harry had been ready for this question. He had been turning over the answer for the past hour, finding its edges, deciding how much of it to hand over. "I found out," he said. "The castle has a lot of history in it. If you know where to look and how to ask, it tells you things."
"How to ask," Theo repeated slowly.
"How to look," Harry said. A slight adjustment. Not a lie. Not the whole truth. Exactly enough of both to be technically accurate and functionally opaque.
Theo looked at him for a long moment. Harry could see him doing calculations — weighing what he'd just been given against what hadn't been said, calculating whether the gap between the two mattered enough to press on right now, at two in the morning, with the music still going and six days of sleep debt sitting on all of them.
He decided it didn't. Or decided it did and filed it for later. With Theo it was sometimes hard to tell which.
"How does it activate?," Theo said instead.
"Everyone in the room has to agree to it," Harry said. "All of us. It only works if we all key ourselves in willingly. That's how the magic holds." He let that sit for a moment before adding, "It also means that if anything happens inside this room after the ward is up, whoever is responsible is one of us. No external interference means no external suspects."
The room absorbed this.
Burke shifted. Just slightly. Just enough.
Harry didn't look at him directly. He already suspected Burke to have been the person leaking information about him to Vaisey.
"That's not nothing," Blaise said quietly, from his bed. His voice was neutral, but his eyes were on Burke too.
"No," Harry agreed. "It's not."
"You're asking us to vouch for each other," Theo said.
"I'm asking us to protect ourselves," Harry said. "What we vouch for is our own business."
Draco was quiet for a moment, looking at the floor. The music climbed again. He closed his eyes briefly, and when he opened them something had settled in his expression — not warmth, exactly, but the exhausted pragmatism of someone who had run out of better options.
"Fine," Draco said. "Do it."
Blaise nodded once.
Theo looked at Harry for another moment, then looked away. "Yes."
Zacharias Smith said nothing. He simply held out his hand in the gesture Harry had described — the one that keyed the magic in. His face was entirely unreadable. He had not, Harry noted, said a single word during the entire conversation.
Everyone looked at Burke.
Burke looked back at the room. Five faces, varying degrees of tired and expectant and watchful. The music continued its patient assault on the ceiling.
"Fine," Burke said. His voice was flat. He didn't look at Harry when he said it.
Harry noted that too.
He pressed his hand to the stone of the dormitory wall — the specific place he had identified earlier, where the old magic sat closest to the surface, where the castle's original intention was still legible if you knew how to read it. He didn't speak aloud. He didn't need to. The language he used was older than the school and quieter than speech and the castle recognized it the way it recognized everything that had ever been part of its foundations.
The ward settled into place like a door closing.
Not dramatic. Not loud. Just — present. A change in the quality of the air, the way a room changed when a window was shut against the weather. Harry felt it the same way he felt all the castle's magic — not as a spell but as an intention, something alive and old deciding to pay attention.
The music stopped.
Not faded. Not wound down. Simply stopped, between one beat and the next, as though it had never been playing at all.
The silence was enormous.
Nobody spoke for a long moment.
"Oh, thank Merlin," Draco said, and lay back down, pulled his covers over his head, and was apparently asleep within thirty seconds.
Blaise looked at the wall where Harry had pressed his hand. Then at Harry. Then he lay down too, with the air of a man who had decided that understanding things was a problem for a more rested version of himself.
Theo was the last one sitting up. He looked at Harry across the quiet dormitory with an expression that was thoughtful and patient and not quite finished.
"How to look," he said again, softly. Almost to himself.
"Good night, Theo," Harry said.
Theo lay down.
Harry sat on the edge of his bed in the sudden silence and listened to the castle breathe around him and thought about Burke's face when he'd said fine, and the way Zacharias Smith had extended his hand without a word, and the particular arithmetic of a room full of Slytherins deciding, for the first time, to trust each other.
Not because they liked each other.
Because it was useful.
Which, in Slytherin, was close enough.