Chapter Text
The staircases of Hogwarts were a wonder in themselves—grand, sweeping things of carved stone that clicked and swung into place like pieces in a living maze. Most students had long accepted their whims, groaning when the steps carried them away from class or cheering when, by sheer luck, they landed on the right floor. To everyone else, the staircases were simply part of the castle’s eccentric charm.
But not Harry Potter.
He and Ron stood at the top of one now, leaning over the banister as it slid with stately precision into alignment with another flight. The stone groaned faintly, chains clinking deep inside the walls as though the castle itself were alive.
“They move quick enough, yeah?” Ron said, nodding down as the staircase settled into place. “Look, it’s lined up already.”
Harry squinted, his brow furrowing in that way Ron knew meant trouble. “But what if you’re in a real hurry? Say—you’ve got three minutes to get to Snape’s class before he takes fifty points off for being late? What then?”
Ron grimaced. “Then you run. Stairs or no stairs, you just leg it and hope for the best. Everyone knows that.”
Harry tilted his head, restless with the thought. “We could test the efficiency of it.”
Ron blinked. “Test… how?”
Harry leaned further over the railing, eyes glittering with feral excitement. “Physics. We make an experiment. See if the staircases move faster on their own, or if something going down them would beat them. Start at the top, measure how long it takes to reach the bottom. Compare that to how fast the staircase moves itself.”
“Harry,” Ron said flatly. “It’s a magic school.”
“Still physics,” Harry shot back. “Magic doesn’t cancel out basic laws of the universe. Objects still fall. Students don’t use brooms or spells on the stairs—they walk. Which means the stairs are competing with physics. And I want to know if they win.”
Just then Draco and Blaise rounded the corner mid-argument, footsteps hurried and uneven.
“I’m telling you,” Draco was saying sharply, “the portraits watch me. Not in the general ‘we observe students’ way—specifically me.”
Blaise snorted. “Maybe they’re admiring your hair. It’s blinding in torchlight.”
“Bugger off,” Draco muttered, but he lifted a hand to smooth it anyway.
“Oi, Malfoy, Zabini!” he called, his voice echoing against the vaulted ceiling. The two blinked at Harry. “Which do you think is faster—the staircases moving on their own, or someone going down them?”
Draco blinked, thrown. “Obviously the staircases. They’re enchanted.”
“Not necessarily.” Harry straightened, suddenly sounding more like a lecturer than a first-year Gryffindor. “Think about it—momentum, velocity, acceleration—”
“—gravity,” Ron added proudly, like it was the cleverest word he’d ever said.
Harry snapped his fingers. “Exactly! How could the stairs keep up with a body in motion? Magic, sure, but how would the enchantment know the speed it needed to match?”
Draco’s mouth opened, shut, then opened again, his face pinched in outrage. “That’s ridiculous! The castle just… knows. It’s enchanted!”
Blaise, to everyone’s surprise, didn’t scoff. He tilted his head, intrigued. “You’d need to test it. Something fast enough to go down the stairs, but with the weight and balance of a person. A book wouldn’t work—it’s too flat. Gobstones would bounce. You’d need an object closer to human shape. A dummy, maybe.”
Harry grinned like Christmas had come early. “Exactly! A proper experiment.”
Ron frowned. “You mean like… chucking someone down the stairs?”
“Preferably someone we don’t like,” Draco muttered.
“Why not you?” Ron shot back, grinning. “You’re always falling over yourself anyway.”
“I am not!” Draco looked scandalized, clutching the railing as though Ron might really try it. “This is the most reckless, idiotic idea I’ve ever—”
Harry ignored him, thoughts already spinning. “If we had a weighted dummy—or something transfigured—we could compare the time it takes to fall versus the time it takes for the staircase to rotate into place.”
Blaise smirked faintly. “But you’d need a constant starting point. Same height, same angle of release. Otherwise your data’s worthless.”
Ron squinted. “Data? We’re at Hogwarts! You lot are talking like Muggles in a lab.”
Draco groaned, dragging a hand down his face. “Merlin’s beard, you’re all insane. You’ll get expelled before Christmas.”
Harry’s grin turned sharp, almost daring. “Give me until tomorrow. I’ll have it ready by then.”
The glint in his eyes made even Draco hesitate—just for a moment—before huffing dramatically and muttering, “Fine. But if anyone dies, it’s on you, Potter.”
-The Next Day-
The contraption in front of them was unmistakably a couch—or at least it had been, once. Its faded upholstery sagged in places, and one armrest leaned at a suspicious angle as though ashamed of being attached at all. Beneath it, however, Harry had somehow fastened a set of curved wooden runners. They gleamed faintly, charmed to stay slick and resist splintering, giving the whole thing the look of a sofa that had decided to moonlight as a sleigh. A tangle of rope was knotted to the front like reins, and extra cushions were crammed haphazardly across the seat, lashed down with lengths of twine to keep them from bouncing loose.
It wobbled whenever someone breathed too hard near it. It looked both ridiculous and vaguely threatening.
It was, in short, a couch-sled: ungainly, heavy, and only half-stable—but undeniably capable of sliding.
Draco froze, his mouth falling open in sheer disbelief. “What is this?” His voice climbed an octave. “You said dummy, Potter. This is—this is a furniture graveyard!”
Harry looked up from where he crouched on the floor, grinning with a manic gleam. “Not a graveyard. A sled. Well—sort of. A couch-sled.”
Ron’s face split into a grin as he hefted a moth-eaten cushion into place. The whole frame groaned in protest. “Brilliant, isn’t it? Heavy enough to have proper weight, soft enough not to kill anyone if it flips, and—look—armrests! For balance!”
“Balance?” Draco squeaked, nearly shrill. “That thing couldn’t balance on a flat floor, let alone a staircase that moves!”
Harry dusted off his hands, eyes shining. “That’s the genius of it. I saw this Muggle film last year—called Home Alone. Kid uses a mattress to ride down his stairs like a sled. Looked incredible.” He slapped the couch affectionately. A small puff of dust erupted, making Draco flinch back. “Same principle. Only bigger. Better.”
Ron leaned forward, fascinated. “You can ride mattresses? Brilliant! Why haven’t wizards ever thought of that?”
“Because wizards,” Draco hissed, clutching the banister as if for dear life, “aren’t completely mad!”
Blaise stepped lightly over a discarded chair leg; hands tucked in his pockets as he surveyed the creation with calm amusement. His lips quirked as though he couldn’t quite decide if Harry was a lunatic or a visionary. “I’ve got to admit, Potter—it’s bold. But how do you know the staircases will even register it? They might just see a heap of junk and let it crash into the floor below.”
Harry’s grin sharpened. “I’ve thought of that too.”
Before anyone could retreat, Harry grabbed the three boys and all but dropped them onto the sagging couch. “See, you can’t trick enchantments. A fake dummy wouldn’t convince the castle. But a living subject? Different story. The magic would have to react.”
Ron blinked. “Living subject?”
Harry planted both hands on the backrest, leaning over them like he was about to reveal the cleverest secret in the world. His green eyes glittered. “So I thought—why not?”
Draco’s eyes narrowed. “Why not what?”
(Start Can Can by Offenbach song here)
“Why not us?” Harry said cheerfully.
And with a sudden, merciless shove, he sent the couch hurtling forward. The runners caught the stone with a screech, and the couch lurched onto the staircase just as Harry vaulted over the backrest to join them.
“WAIT—WHAT?!” Draco’s scream split the air, bouncing off the vaulted ceiling as gravity seized them all. The couch-sled groaned, wobbled, and then shot downward like a bewitched battering ram.
The couch launched down the stairs with a jolt that threw all four boys backward.
“BLOODY HELL!” Ron roared, clinging to the armrest like it was a lifeline.
“WE’RE ALL GOING TO DIE!” Draco shrieked, his scarf snapping like a banner in the wind.
Blaise was swearing fluently in Italian, his calm façade crumbling as the couch bounced hard enough to rattle teeth.
And Harry—Harry was laughing. Wild, bright, unstoppable laughter that echoed through the stairwell as the couch picked up speed.
The enchanted runners hissed against the stone, sparks crackling as the staircase shifted beneath them. The couch didn’t falter. It leapt the gap like a charging Hippogriff, slamming onto the next flight with a bone-jarring thud. Dust rained from the ceiling.
“IT’S NOT SUPPOSED TO JUMP!” Draco screeched.
“Hang on, hang on, hang on—” Ron yelled, bracing himself as they spun around a corner so fast that one leg of the couch actually lifted.
Blaise, teeth clenched, muttered, “Merda, merda, merda—”
The staircases twisted wildly now, swiveling into place almost in anticipation, turning every step into a dizzying trap. At each new junction, Harry whooped louder, flinging his arms like a boy on a carnival ride. The others screamed, cursed, or simply held on for dear life.
At one junction, the staircase slid away too soon. For a terrifying second they were airborne—weightless—before slamming down on the next landing so hard that every spring in the couch screamed. Draco’s shriek cracked an octave higher.
Halfway down, a cluster of Hufflepuffs screamed and scattered as the couch barreled past, narrowly missing them. One dropped a stack of parchment that fluttered into the air like panicked owls.
“WE’RE GOING TO KILL SOMEONE!” Draco howled, horrified.
“Better them than us!” Ron shouted back.
The couch hit another landing, bounced—actually bounced—and then shot forward as if launched by a catapult. It slid beneath a swinging portrait just in time, the painted knight inside leaping back with a scandalized cry.
“WHAT IS THAT?!” the portrait bellowed, but it was already behind them.
Staircases twisted wildly now, clicking and locking into dizzying configurations. The couch careened down one flight so steep Draco nearly fainted, then whipped around a hairpin turn so sharp Blaise had to yank Ron upright before he toppled over the side.
“THANKS!” Ron yelled.
“DON’T THANK ME YET!” Blaise shouted back.
Then—of course—Peeves arrived. The poltergeist appeared overhead, upside down, clutching chalk in both hands.
“WHEEEE! WHAT A RIDE!” he howled, bombarding them with dust and erasers. “Faster, faster, faster!”
A chalkboard eraser exploded against Draco’s head, leaving a white puff of dust in his hair. “I HATE THIS SCHOOL!” he wailed.
Another staircase twisted mid-slide, sending the couch into a sharp downward spiral like a corkscrew. All four boys screamed as their stomachs tried to catch up. Harry threw his arms wide and howled with feral glee. Draco clamped his eyes shut, muttering prayers to Merlin himself.
And then—suddenly—they weren’t on stairs anymore. The final flight spat them out onto the smooth marble floor of the Entrance Hall. Momentum carried the couch forward like a charging beast straight toward the huge double doors—
—which swung open at that exact moment.
The boys screamed as one as the couch sled rocketed into the Great Hall.
Gasps erupted from hundreds of students as the monstrous contraption skidded across the floor between the long house tables, scattering plates and cups in its wake. Gryffindors dove aside. Slytherins shrieked. A Ravenclaw prefect actually fainted into her pudding.
The couch fishtailed, throwing Ron halfway across Blaise’s lap. Pumpkin juice fountained skyward as an entire jug went airborne and dumped itself over a cluster of first-years.
“MY TOAST!” someone screamed.
It clipped the edge of the Hufflepuff table, sending a tray of sausages flying like javelins.
The couch spun, screeched, and at last slammed to a halt at the foot of the staff table. One armrest tore loose and rolled in a sad circle before thunking against Snape’s boot.
The silence that followed was deafening.
McGonagall’s lips had vanished into a single white line. Dumbledore’s eyes twinkled so hard it looked painful. Snape looked like he’d just aged ten years, his expression hovering somewhere between murderous rage and existential despair.
The boys sat in a heap, hair wild, faces pale, eyes wide.
Blaise shakily got off the couch, calmly dusted himself off and said, “Ten out of ten would recommend.”
Ron, still wheezing, nudged Draco in the ribs. “Same time tomorrow?”
Draco made a strangled noise and collapsed on the floor.
Harry, grinning with feral brightness, leaned back against the broken couch. “I’d call the experiment a success."