S1E5 — : Halloween, Weather Advisory
The castle woke to October with a grin full of pumpkin seeds. Banners grew themselves; candles approved; suits of armor practiced their "boo." Corvus crossed the common room with his tie exactly imperfect and the locket warm against his collarbone, the black coin in his pocket clicking once like a metronome that had decided today deserved a tempo.
Ravenclaw's eagle asked, "What is more frightening than a question you cannot answer?"
"A certainty you won't examine," Corvus said, and the door, to its credit, let him out anyway.
Down in the Great Hall, the ceiling was a sky stitched with gray, clouds heaped like thoughtful cats. Jack-o'-lanterns floated in orbits above the tables, their smiles ranging from benign to union-busting. The morning smelled of cinnamon and ambition.
Fred and George materialized at his shoulder, twin conspiracies. Daphne Greengrass appeared half a heartbeat later, clean and composed as a blade in a sheath.
"Status check," Fred murmured.
"Breadcrumb motes primed," Corvus said. "Code word Home. Prefects and staff tagged. Self-immolate at midnight."
Daphne's mouth quirked. "How domesticated of you."
"Proper mischief is house-trained," Corvus said. "Today we behave. After all, it would be a shame if any unexpected chaos tried to compete."
"Perish the thought," George said, and a pumpkin lantern above them flashed as if it knew a joke and had elected to keep it.
Corvus buttered toast. The golden trio several tables over were becoming a constellation the school kept glancing at; he let his eyes skim and move on. He had a date with infrastructure.
> 31. Halloween protocol: motes (CV-006) deployed; Hallway Compass (CV-005) wide awake until curfew; Reader's Halo off—encourage feasting, not essays.
31a. If catastrophe, get the little ones to Home. Do not play hero. Heroes are a resource sink.
---
Bats, Bells, and Binns
History of Magic, late morning: Professor Binns droned like a very patient beehive; the class performed synchronized wilting. Corvus occupied himself by testing a small silent charm on his quill—ink that thickened when he grew bored, thinned when he paid attention. By minute fourteen, it was soup. He sighed and thinned it out of pity.
When the spectral bell finally tolled, they escaped into a corridor dim with garlands and bats. Peeves shot past upside down, festooned in bells, singing something uncharitable about professors' socks. He paused midair, flipped, and hovered nose-to-nose with Corvus.
"Widdle Raven with the tidy grin," Peeves trilled. "Got any crimes I can borrow?"
"Only ethical ones," Corvus said. "They wash out."
Peeves made a face as if presented with salad. "Boo," he said conversationally, and vanished through a suit of armor that took it personally.
Daphne matched pace with him, hands in pockets, not looking as if she were matching pace. "Slytherin rumors say you've been leaving breadcrumbs on professors."
"Slytherin rumors sound tasteful for once," Corvus said. "Tell them not to panic. The motes are more polite than most boys."
"Low bar." A pause. "Thank you."
He didn't look at her. "For Slytherins?"
"For first-years," she said, and disappeared into the green-trim tide.
---
Professor Weather
Charms before lunch felt like a warm front. Flitwick had put a tiny paper bat on the corner of his lectern; it bobbed with an earnest sense of occasion.
"Articulation!" he cried, standing on his stack of books. "Incantations are music. Enunciate, or your magic will yawn and wander off."
They practiced a suite of small spells—light, dry, warm—until the room smelled like toasted quills and triumph. When the bell rang, Flitwick caught Corvus's eye with a tilt of the head that said stay a moment, if you would.
"Mr. Black," he said when the room had emptied, "how is our… purely hypothetical… infrastructure?"
"Humming," Corvus said. "Hallway Compass is helpful, not pushy. Breadcrumbs keyed to Home. Teacup Choir on hiatus till tomorrow."
Flitwick's moustache twitched. "Very good." Then, softer: "I hope we won't need your good sense today."
"So do I," Corvus said. The coin warmed in agreement.
---
Feast Forecast
By evening the Hall had transformed from everyday miracle to celebration. Pumpkins hovered. A thousand bats wheeled overhead like punctuation marks. Platters appeared in a rush of scents: roast, spice, sweet; the delirium of a kitchen in love with its own competence.
Ravenclaw filled with the rustle of anticipation and napkins. Corvus took his seat at the far right as usual, where the windows held the last smear of daylight. He watched the room fill—Hufflepuffs with contentment, Gryffindors with noise, Slytherins with the smugness of black velvet in good lighting.
He wasn't watching Harry Potter. He wasn't not watching. He catalogued the lay of the room out of habit: prefect positions, staff spacing, exits, stair availability. The out-of-bounds door three floors up hummed in memory like a tooth you've promised not to prod.
"Bet on whether someone enchants the pumpkin juice?" Fred asked, sliding in.
"Don't tempt fate," Corvus said, "she's easy."
They ate. Corvus practiced heroic restraint by not designing a condiment that corrected rudeness. He timed the refill on the gravy boat (two seconds faster than goblets; interesting). He felt the coin pulse once and learned, just then, what it felt like when the castle held its breath.
The Hall's volume dipped. Not enough to remark on consciously; enough to make a man listening to wardlines glance up.
He glanced up.
Quirrell ran in. He wasn't pale so much as erased. His turban looked too heavy for his head. His voice was the kind of scream you can tell hurts to make.
"TROLL—" he gasped. "IN THE DUNGEON—" The echo came back like a slap. "TROLL—IN THE DUNGEON!" He blinked, almost astonished by himself, then pitched forward in an admirable faint.
The Hall erupted. It sounded like numbers falling down stairs.
Dumbledore didn't shout. He twirled his wand; a rafter-deep bang cracked the air and made the banners tremble into attention. "Prefects," he said, his voice a guide rope, "lead your Houses to their dormitories immediately."
The coin burned cold against Corvus's chest. He stood before his legs admitted it, already mapping pathways in his head.
"Breadcrumbs," he said to Fred and George.
"Home," they said together, not smiling at all.
Ravenclaw surged as one. Corvus vaulted the bench and went parallel to the flow, not against it, shepherding with his eyes where his hands couldn't reach. Hufflepuff first-years clutched at one another like laundry. The Hallway Compass charm woke in the stone with a pleased hum and began nudging hems and eyes toward the correct arches.
He saw it happen: a boy near tears whispering Home without knowing why, and the mote on Professor Flitwick's lapel brightening for just him—visible from halfway across the Hall, a small steady light in a moving sea.
Flitwick's head turned like a compass finding north. He wove to the boy as if he had intended to do that all along. Corvus exhaled a breath he hadn't admitted he was holding.
> 32. Emergency protocol: engaged. Breadcrumb utilization confirmed. Compass effective. Children are very brave.
McGonagall became architecture at the front, Gryffindors coalescing around her spine. Snape rose slower than the rest, eyes cutting to the staff table, then the door, then—subterranean calculation—elsewhere entirely. Quirrell remained a theatrical heap.
Dumbledore's gaze flicked across the Hall, touching houselines like tuning forks. For a second that felt like ten, his eyes fell on Corvus. Recognition. Instruction. Get them upstairs.
Corvus nodded once. He turned to Ravenclaw. "Right side—windows—single file—follow the prefects—don't push—good—good—thank you," he said, a litany of tiny spells made of words. The corridor took them like a river takes leaves.
In the crush, Susan's eyes found him across a wedge of Hufflepuffs; she mimed a halo and pointed at a cluster of first-years under her wing. He flashed two fingers—with you—and kept moving.
They crested the first staircase as the castle decided to complicate things by changing its mind. The treads sighed and swung; the handrail vibrated a question.
"Not now," Corvus told it, very politely. "People are smaller than your jokes."
The staircase—abruptly, astonishingly—held still.
"Thank you," Corvus said, and would have kissed the newel post if that wouldn't have started rumors.
They took the second landing at a trot. Somewhere deep below, the wrong harmony he'd been hearing all week grated through the masonry—the kind of sound that makes your teeth hurt even if your ears don't. He resisted the urge to chase it. He was not a hero today. He was an engineer.
One Ravenclaw first-year froze halfway up, ironed to the step by panic, eyes gone wide to let in more fear.
Corvus slid in front of him so the world was only boy, robe, coin-warm and pocket-dust. "Hey," he said, a softness he kept for owls and cupboards. "What's your favorite shape?"
The boy blinked. "A—triangle?"
"Excellent taste." Corvus held up his hands. "Make me three with your breath. In and out—one. In and out—two. In and out—three. Now we move on a four."
They did. The boy's steps found their way back under him. The stair didn't dare shift.
At the turn for Ravenclaw Tower, the bronze eagle riddle-keeper asked, earnest as ever, "What runs, but never walks?"
"Water," Corvus said, breathless, "and a sensible mind in a crisis." The door seemed to consider adding applause but settled for opening wide.
Prefects poured children through. Corvus counted heads, because counting was a spell too. Paradox beat down from the rafters, furious and helpful, and pecked a boy's sleeve away from a hinge. In the corner of his vision, the coin flared and cooled, flared and cooled, like a lighthouse trying not to be obvious.
When the last of the smallest was inside, Corvus stepped backward into the hall, letting the door's hush wash out the noise. The corridor was a lot of distance and two seconds long. Somewhere below, a sound like stone remembering it was older than trolls rolled up the walls.
He looked down the spine of the castle toward the lower floors and felt every good intention in him lean that way.
He kept his feet where they were.
> 33. Engineering ≠ heroics. Deliverables: safety, count, calm.
33a. If you leave your post, make sure it's for a system, not a gesture.
He turned—and the bronze eagle, as if it had waited for the right moment, posed him a final question: "When is a door not a door?"
"When it is a promise," Corvus said, and the door settled like a cat, very satisfied with its boy.
Behind him, Ravenclaw murmured into quiet like a library finding its shelves. Ahead, the castle re-tuned itself for a fight he wasn't going to watch.
He pressed the coin through his shirt and whispered, "Hold them."
The metal warmed, once, a heartbeat he recognized now—a yes—and the school, vast and old and amused even now, took a long breath in.
The tower swallowed Ravenclaw like a lighthouse swallowing sailors—dry, lit, strict about railing etiquette. Prefects did the counting dance; younger voices trembled into quieter shapes. Corvus moved along the wall, turning panic into inventory.
"Feet off the hinge," he murmured to one boy.
"Breathe in triangles," to another.
"Good. Excellent. Keep your questions, we'll answer them when the world sits down."
He threw a soft net over the common room: Reader's Halo repurposed without the reading—sound thinned for sharpness, thickened for comfort. Not a silence; a quilt. Chandeliers stopped pretending to flicker and simply glowed.
> 34. CV-003 variant: Calmfield; ten-foot radius; opt-out by stepping through. No compulsion. Respiration rate stabilizes in ~30s.
Paradox patrolled the rafters like a small feathery prefect with union rules.
A first-year girl with tear-glossed lashes tugged his sleeve. "My brother—he's in Hufflepuff—I don't know if—"
"Code word?" Corvus asked gently.
She blinked. "Code—?"
"Home."
She swallowed, brave. "Home."
The Ravenclaw motes weren't hers, but the castle was, and Beacon Breadcrumbs obeyed the larger geometry. Somewhere two floors down, a little light on a Hufflepuff prefect's shoulder brightened for one heartbeat. Corvus pointed through the open arch where the stair's wind drew. "He'll see the nearest light. He'll follow it. So will you: sit, drink water, think of three kind things to tell him when he arrives. That's your part."
She nodded, task in hand, terror downgraded to waiting.
The floor under his shoes thrummed—once, twice—as if the school were stomping its foot to settle its balance. The wrong harmony from below cut off mid-snarl. A crash, thin and far. Then the sound of teachers doing what teachers do when administrators stop speaking: moving.
He kept his post.
---
The All-Clear
"Students may return to their feasts," McGonagall's voice carried through corridors like a spell that tastes of chalk and steadiness. The bronze eagle asked a perfunctory riddle; Corvus answered without hearing it. The room exhaled. Children did, too.
He dismissed the Calmfield. Prefects opened the gates. Ravenclaw poured back toward the Hall, laughter thready and giddy the way it is after fear's back breaks.
On the moving stairs, the handrail buzzed a question. "You were impeccable," Corvus told it. The treads settled into a smug, well-earned stillness.
The Great Hall had reset to celebration with a slightly dented bravado. Pumpkins still hung. Platters reappeared as if the kitchen refused to let danger interrupt competence. Harry Potter sat, intact, between a redhead and a girl with a new, fierce place in the world—Hermione's posture read like a vow someone had written on her bones.
Dumbledore stood. The room leaned toward him the way flowers lean toward a window. "Troll is in the dungeons no longer," he said mildly, which was both obvious and an apology for the pun. A wave of relief, laughter trying on courage, teachers taking inventory with their eyes.
Across the hall, Snape's gaze grazed Corvus like a thrown cloak—weight, temperature, meaning, and gone. Flitwick's found him properly—there and warm: Well done, boy. Corvus inclined his head Like you taught me and sat.
Fred and George didn't shout. They bumped his shoulders, left and right, the way brothers do when words would break the weather they like. Daphne passed behind him, not looking, and murmured, "All Slytherin first-years accounted for. Your motes worked."
"Good," he said, equally not looking. "Tell no one it was us."
"Obviously," she said, amused. "We'll blame Hufflepuff."
He ate. He discovered you can taste adrenaline on pumpkin pasties if you pay attention. He pretended not to. Notes on his cuff read themselves like heartbeat:
> 35. CV-006 (Breadcrumbs): visible activations (observed): 9; inferred: 14–18.
35a. Compass nudges accepted > 80%.
35b. Stair cooperation rate 100% under direct politeness.
At the staff table, Quirrell had reassembled his physical imitation of a man who isn't a scream. The wrong harmony didn't hum now; it sulked. Corvus kept a polite distance from it in his mind.
---
Debrief, Informal
After the feast resumed pretending it had never paused, Flitwick waylaid Corvus with the ease of a conductor catching a promising oboe.
"Walk with me, Mr. Black."
They skirted the edge of the Hall where sound thins into architecture.
"Your… hypothetical lights." Flitwick's moustache twitched. "How many?"
"Nine I watched," Corvus said, "and a handful more the system didn't tell me because the system is civilized."
"Very good," Flitwick said, pleased by that exact word. "And the staircases?"
"Responsive to flattery." Corvus kept his tone plain. "If one thanks them for prioritizing safety, they behave like champions."
Flitwick's eyes warmed. "We forget to thank the tools that carry the world." He lowered his voice. "There are some doors, Mr. Black, that will hear you if you knock politely. There are some that will not. You must, as you're doing, learn the difference."
"I'm practicing restraint," Corvus said.
Flitwick patted his sleeve. "An underrated magic." He angled his head, almost casual. "And—should you hear discord where harmony should be—choose witnesses or walls, not thresholds. Doors are where stories get teeth."
"Witnesses or walls," Corvus echoed. "Noted."
---
Inventory of Aftermaths
Back in the tower, the young wore their bravery like oversized jumpers. Prefects conducted the ritual of hot chocolate and scolding. Someone started a "troll song" in a key that offended the chandelier; Corvus deployed Teacup Choir in miniature over a single kettle. The harmonies nuzzled the room into kindness.
He checked on the girl with the Hufflepuff brother. She was mid-hug, performing her three kind things like an oath. He let that be.
He climbed the dormitory stairs, locket warm against his throat, coin cool like a clear head. The window gave him lake, tower, stars—Hogwarts's face after a smile.
Mystery Log:
> 36. Halloween, deliverables met.
– No heroics; yes systems.
– Children processed fear into stories at a rate I envy.
– Staff: Flitwick pleased; McGonagall iron; Snape weather moving east.
– Troll: neutralized offstage. Gryffindor saga consolidating (three points of a triangle).
36a. Lessons:
– Politeness moves stone.
– Panic looks like stillness from the outside. Ask for favorite shapes.
– Doors are promises. Keep the ones you make to them.
He shut the book. Frost feathered a small circle on the pane. Letters flowered in the cold, deliberate and old:
Well asked.
He touched the glass with two fingers. "Thank you," he told the castle, like you thank a tool that carried the world all day.
The frost cleared.
---
A Corridor, Later
He didn't plan to patrol. He did plan to walk, softly, the way you do when your head is too full of thens. The Ravenclaw door let him out with a riddle he answered with muscle memory. The corridor wore the late hour like a shawl.
At the turn by the fourth gargoyle, Daphne leaned half in shadow, posture relaxed in the way of people who could become a knife in one sentence.
"You didn't go looking for the troll," she said. Not a question.
"I looked for stairs and small lungs," Corvus said.
"Mm." She eyed him. "Pranks that help are unfashionable. Keep making them. We'll see if fashion notices."
"Thank you for your endorsement, Lady Trends."
She almost smiled. "Try not to get murdered by a door."
He tipped an imaginary hat. "Working on it."
They parted like two punctual secrets.
---
Two Teachers and a Shadow
At the base of the next stair, he met Snape coming the other way—robes a traveling argument with gravity, hair accusing the air of impure thoughts. Corvus stood aside with the exact measure of deference that says I am not afraid, and I will not obstruct.
"Black," Snape said, tasting the name the way one tests tea for poison.
"Professor," Corvus said evenly.
Snape's gaze snagged, briefly, on the coin's outline under Corvus's shirt—then on the boy's steady hands. A beat. "Ravenclaw," he added, making the word do five jobs at once.
"I take the accusation with grace."
Something that might have been humor, if starved, tugged at Snape's mouth. He moved on, shadow trailing like a cloak's opinion.
At the turn toward the Charms corridor, Quirrell appeared from a side passage with the delicate, careful steps of a man who fears he might wake up the floor. His eyes flitted over Corvus and didn't land. The wrong harmony fluttered, then stilled, like a moth beneath a jar.
"G-good night," Quirrell stammered.
"Sleep is a spell, Professor," Corvus said, bland. "Cast it well."
Quirrell's mouth made a shape that might have been almost gratitude, then smoothed itself into absence. He left the air colder by two degrees.
Corvus didn't follow. Witnesses or walls. Not thresholds. He chose wall—his palm on cool stone until the stone warmed back.
---
The Room That Listens
The hidden classroom accepted him as if the day had exhausted it, too. He laid biscuits on the windowsill for no one in particular. He placed the coin and the locket side by side on the desk, small moons with different gravities, and didn't open either. Promises, kept.
On the slate he wrote:
> 37. CV-007 — Breathkeeper: a pocket charm for steadier lungs; trigger = favorite shape.
37a. Tie into Calmfield; deploy via prefect pins; opt-in only.
Underneath, in smaller hand:
> Not by blood noble, but by choice → Build the choices so others can take them.
The chalk felt lighter by the time he set it down.
Back in the tower, the bronze eagle asked, "What can you hold in your left hand but not your right?"
"My right elbow," Corvus said, and the door laughed, actually laughed, a bright bronze chuckle that sounded like relief with good manners.
He fell into bed. Up in the rafters, Paradox muttered a final complaint and decided to forgive him tomorrow. The lake exhaled a longer wave. Somewhere far under stone, the wrong harmony writhed and went quiet, like a bad idea told to hush. Somewhere nearer—three Gryffindors—friendship braided itself tighter, consequence and care in equal measure.
The coin warmed once against his ribs, a single, small yes. He slept like people do when they have chosen systems over spotlights.
---
Morning After (Addendum)
Dawn made gray tea of the windows. Corvus woke to a note slid under his door—no handwriting, just the school's tidy script:
> Mr. Black—
Your conduct under disturbance: noted and appreciated.
Please see Professor Flitwick today for an errand of no great danger and excellent importance.
— The Deputy Headmistress
He smiled into his pillow, then sat up and reached for the Mystery Log.
> 38. Post-event: when institutions see you, choose your next question carefully.
38a. Ask for errands that build infrastructure. Decline capes.
He closed the book. The tower stretched. Downstairs, the bronze eagle had a new riddle queued and proud of itself.
"Doors as promises," he told the ceiling, because sometimes ceilings deserve a compliment. "I'll keep mine."
Outside, Hogwarts cleared its throat, tuned its corridors, and began another day.