CASS162- Duel?

Harry turned up before the Christmas break ended, for another round of Patronus training. Cassian just gave him a once-over and raised a brow.

"Neville's not here. It wouldn't be fair, would it?"

Harry frowned. "How about I train, and you correct my mistakes?"

Cassian sighed through his nose, trying not to be impressed. "Fine. That was really Slytherin of you, by the way."

Harry grinned faintly. "Sorting Hat said I'd do well in Slytherin, too."

Cassian hummed. "And you speak Parseltongue."

Harry shrugged. "Didn't ask for that one."

Cassian stood, "No one asks for weird magical talents. They just wake up one day and realise they can talk to snakes or knit sentient scarves."

Harry snorted.

"Wand out," Cassian said, rolling his shoulders. "Let's see if you're any worse without Neville to guilt you into effort."

Harry didn't rise to that. He stepped into position, wand raised.

The first try was a puff of light. Second, mist. Third try nothing.

A few more attempts and the boy sat down hard, panting as if he'd just sprinted across the pitch. His jumper was clinging damp to his back, wand clutched in his hand.

Cassian crouched nearby, not bothering to offer a hand.

"What's your happy memory?" he asked.

Harry looked up, caught off-guard.

"What?"

Cassian gestured vaguely. "That thing you're meant to be thinking about when you do this spell. Happy memory. You've got one, right? Or are we firing blanks on pure optimism?"

Harry glanced down at his wand. "Er. I think so?"

"That's promising," Cassian muttered. "Right. Listen. I know it's personal. Not asking for a diary entry. But clearly, something's missing. You're managing the mist, so the spell's trying to work, which is more than most can do at your age. But that fuel source of yours—"

He tapped his temple. "—is barely lighting the lantern."

Harry frowned. "I thought I was doing alright."

Cassian snorted. "You're doing better than I expected, honestly. But that's not the goal. The goal's not 'well done, gold star, now die anyway.' You're aiming for a proper shield."

Harry wiped his forehead on his sleeve. "I thought the memory just had to be happy."

"Happy's a start," Cassian said, standing. "But not enough. Needs to mean something. Deep enough to grab onto when everything else is falling apart. Not just 'once had a good treacle tart.'"

Harry looked at the floor again.

He started pacing, slowly, arms folded. "There's a reason they don't teach it in Year Three. Especially when even most adults can't cast this spell. Takes more than wandwork. It's a gut-level thing. You've got to reach for the one memory that's yours and hold on like the world's ending. Because sometimes, it will be."

"It is my family and me. Sitting, laughing, hugging."

Cassian dug his nails into his palm.

"That's not a memory, Potter."

Harry looked up, confused.

Cassian didn't soften it. "It's a mirror trick. Doesn't count."

The boy blinked. "How do you know that?"

Cassian rubbed the back of his head. "Saw you. Your first year. Standing in front of the Mirror."

The shift on Harry's face was fast, sharp little twist of embarrassment and something heavier, dragged up from where he'd been keeping it buried.

His voice snapped, "What am I supposed to do then? I haven't got one, have I?"

Cassian crossed the space and dropped a hand to the boy's head, gave it a light ruffle.

"Course you do," he said. "If you didn't, the Dementors wouldn't be chasing you this relentlessly."

Harry didn't look convinced. His shoulders had gone stiff again, jaw tight.

Cassian let out a slow breath. "They're not drawn to you because you're weak. They come because you've got more to take. They smell it, loss, pain, everything knotted up in your bones. But that means there's something worth protecting in there. Something real."

Harry stayed quiet. His eyes were fixed somewhere near Cassian's boot.

Cassian straightened up, dusted off his sleeve like he was brushing off sentiment. "Start small," he said. "Doesn't need to be a grand bloody memory. Doesn't have to have violins and fireworks. Just has to be yours."

He started walking towards the desk again, then paused halfway. "Oh, and don't bother lying to yourself. Magic doesn't like it."

Harry gave a tiny nod. Might've been agreement. Might've been exhaustion.

Cassian flicked his wand. A flame sparked in the old lantern by the corner. The shadows backed off.

"Come back tomorrow," he said, not turning around. "And bring a memory that happened."

Cassian was halfway to the door, coat in hand, when Harry's voice stopped him.

"Sir?"

He turned. Harry stood awkwardly by the desk, fingers curling at the hem of his sleeve.

"I got a broom," Harry said. "Today. No note. Just... showed up. It's a Firebolt."

Cassian raised a brow. "And let me guess. You didn't immediately fly it straight into the moon?"

Harry didn't smile. "I haven't touched it. I thought... maybe it's from Black."

Cassian looked at him for a beat. Then he stepped back over, set his hand firm on the boy's shoulder.

"Good," he said, quiet but sure. "Bloody good thinking."

Harry blinked up at him.

"I know grown wizards who'd mount that broom before the box hit the floor," Cassian went on. "You didn't let the shine blind you. That's rare."

He squeezed on Harry's shoulder.

"I'm proud of you."

Harry didn't say anything, but his chin lifted a little.

Cassian straightened. "Right. I'll take it to McGonagall. She'll run it through every charm-breaker and curse-sieve we've got. If it sneezes funny, we'll know."

He paused at the door, one hand on the frame. "And if it's clean, you'll be back in the air before your teammates start a mutiny."

Harry nodded. "Thank you, sir."

***

The Firebolt sat in his arms like a living thing, sleek, fast, suspiciously generous. Cassian handed it over to McGonagall without ceremony.

"Don't glare at me like that," he said as she raised an eyebrow. "He's the one who brought it up. I'm just the broom mule."

She didn't argue. Just took it with the sort of care you usually reserve for cursed artefacts or bad eggs from Knockturn.

Cassian watched it disappear into her office, then turned and muttered under his breath, "If that thing is rigged, Black's either brilliant or dramatic as hell."

He rubbed the bridge of his nose. "...Both, probably."

***

When Christmas ended and the students came shuffling back into the castle they found the Duelling Club had moved. No longer sprawled across the polished drama of the Great Hall, it now occupied a high-ceilinged classroom on the third floor.

There were banners. Actual banners. And a platform Cassian had nicked from Flitwick's rehearsal stash. The place looked like someone had tried to host a Hogwarts talent show and forgot to take the stage down.

Cassian stood dead centre, arms wide. Behind him, Hannah Abbott and Susan Bones flanked him like very nervous assistants who'd only realised what they'd signed up for this morning.

He pointed at them, "These two," he said, "decided Duelling Club was getting stale. Repetitive. So, as a totally logical punishment, they're now my sidekicks. Possibly also managers. Depends how well today goes."

Susan rolled her eyes. Hannah beamed.

Cassian clapped. "So, girls, what are we doing?"

Hannah stepped forward. "We spent all of Christmas Break putting together ways to fix the Duelling Club. So we've got ideas, loads of them."

Cassian leaned on the edge of the stage.

"Footwork lanes," Hannah rattled off, counting on her fingers. "A proper practice grid so people stop tripping over their own robes. Target dummies that fight back. Simulated duelling runes, like real ones, scaled down, so they react to spell pressure instead of just puffing smoke."

"Reflection wards," Susan added, holding up a small diagram. "So you can train counters and dodge at the same time."

"And a new scoring system," Hannah said, "based on accuracy, not how dramatic your Expelliarmus looks."

Cassian gave her a slow blink. "You mean to say I can't award points for style anymore?"

"No," both girls said.

He sighed. "Dictators, the lot of you."

Susan pointed to the diagram again. "We also thought we could use the back room for wand maintenance workshops. It's empty most days."

Hannah nodded. "And a corner for first-years who want to observe without getting singed."

Cassian pushed off the platform, hands in his pockets. "And what exactly am I doing in all this?"

"You're supervising," Susan said, far too quickly.

"You're not allowed to make the dummies explode on purpose anymore," Hannah added, before he could ask.

There was a beat of silence.

Cassian glanced between them. "So I get demoted and banned from dramatic teaching aids."

They both nodded.

Next few weeks, Cassian dragged in every professor who hadn't learned how to duck fast enough.

He got McGonagall to sort the Transfiguration blocks, they needed target dummies that didn't explode on contact and training zones that could shift shape depending on spell type. She did it all without blinking, though she did Transfigure one of his diagrams into a toad halfway through, just to make a point.

Flitwick handled the charm stabilisers. He practically skipped into the space once he realised someone wanted his help with something complicated. Wards that flexed under impact, illusion patches for dodge work, pressure plates that recorded spell strength, all cobbled together like the world's most overachieving playpen.

Sprout claimed a corner by the window and filled it with what she called "mildly reactive flora," which in reality meant plants that spat ink or screeched if you aimed a hex too close. One of them tried to eat a practice dummy. She seemed thrilled. Cassian made a note to label it 'motivational greenery.'

Hagrid helped too. Dragged in a few creatures from the Forest, not the sort that mauled students (Cassian made that clear) but things with enough quirks to keep students thinking. An irritable kneazle, a puffskein that mimicked spell incantations and something in a crate that never made a sound and never got opened. Cassian refused to ask. He just marked it Do Not Touch and moved on. 

Bathsheda, of course, handled the runes. She rewrote half the room's foundations while humming under her breath, adjusted the wards so they'd react to spell strength and trajectory, then etched a stabilising ring around the centre dais that pulsed faintly if someone tried to cheat. She didn't even bother explaining it.

By the end of it, the place didn't look like a classroom anymore.

The floor bore layered rune circles under the surface, like someone had trapped a constellation in the wood. There were zones marked for footwork, reaction speed, and resistance training. The back wall had a rotating spell map that flicked through historical duels and let you analyse where they went wrong, Flitwick's idea, naturally.

Cassian stood in the doorway one afternoon, mug in hand, watching the runes flicker.

"Still missing something," he said.

Bathsheda didn't even look up from where she was adjusting the glyph anchors. "If you say 'exploding target dummies,' I'm leaving."

He sipped. "...Can they explode just a little?"

"No."

"Unimaginative."

"You already snuck in the one that smokes when you miss by more than a foot."

Cassian glanced at the dummy in the far corner, which did in fact wheeze like a dying chimney when hit poorly. It looked as amazing as he thought it would.

"Hehe, as for the crown jewel," he gazed at the rows of stalls, a smile tugging at his lips. "This is going to be delicious."

She stood, wiped chalk on her sleeve, and gave him a look. "You're going to have to tell Dumbledore we did this eventually."

Cassian waved a hand. "He'll pretend to disapprove, smile vaguely, and then ask if we can add a section on 'spells of love and harmony'."

"And you'll say no."

"I'll pretend I didn't hear him."

Cassian drained his tea. "Right. Next step, trapdoors?"

"No."

Worth a shot.

That night, when the students arrived for Duelling Club, most stopped dead in the doorway.

Gone was the echo of the Great Hall, the draft, the drama. This new room looked like someone had raided half the castle's supply closets and decided to build a set for a very niche magical game show.

And then there were the professors.

McGonagall, Sprout, Flitwick, Hagrid, and even Aurora, Septima and Charity loitered near the back, arms folded, watching. Bathsheda was standing next to Cassian.

"Welcome to the upgraded Duelling Club."

"Right," Hannah said, eventually. "Um. So."

Susan elbowed her lightly, nodded toward the nearest training lane.

A few students wandered over, curiosity stronger than self-preservation. The target dummy lit up as soon as one of them raised a wand, flashed blue, then gold, then hissed when the spell went wide.

That caught the rest.

Movement rippled through the crowd. Students edged in, spread out, started poking at the different set-ups. The new grid lit under their feet when they shifted stances. A Slytherin pair tried a mirror dodge test and got caught in the feedback ward, one of them yelped, stumbled back, and muttered something that made Professor Vector choke on a laugh.

Hannah was already halfway to the back wall, pointing out the new spell-mapping chart. Susan followed, weaving through a group trying to figure out the footwork lanes without tripping over their own shoes.

A Hufflepuff third-year launched straight into the dummy duel module and nearly got flattened. One of the older Slytherins barged in, wand already out, barely glanced at the warning glyphs before casting. The rune flared red. His spell bounced back and singed his sleeve.

"Bloody hell—" he started, then bit it back when he noticed Cassian watching.

"Reset!" someone shouted from the far corner. The platform shimmered, reformed itself. More students filtered in from the corridor, dragged by the noise or dragged by friends. Within minutes, the place was a proper mess, wands flashing, dummies jolting, runes buzzing like a beehive.

"Finally," Cassian murmured, "someone breaks their nose in a properly calibrated classroom."

***

When the last of the students had finally trickled out, half of them limping, the other half buzzing like they'd just come off a Quidditch pitch, Cassian leaned back against the rail by the duelling dais, mug in hand, hair mussed and coat unbuttoned. The place smelled faintly of burnt ozone and whatever ink Sprout's shrieking plants had belched during the chaos.

Bathsheda sidled up beside him. "So. No one got maimed."

Cassian sipped. "Early days."

She grinned, then, as if sensing the approaching storm, quietly stepped away. "I'll let you handle this one, love."

Cassian turned to ask what she meant and saw the glint of half-moon glasses.

"Traitor," he mouthed at her.

She gave a small, serene wave and kept walking.

Dumbledore strolled in, quiet as a ghost, hands folded behind his back. He didn't say anything at first, just took the room in like it was a painting, wandering slowly along the edges, gaze lingering on the shimmering rune rings and burn-scored target dummies. His expression was neutral. Which was never comforting.

Cassian cleared his throat. "If this is the part where you start lecturing me, can we skip it? I've got tea that's gone cold and a dozen maintenance charms to run."

Dumbledore didn't answer. Instead, he walked to the far end where the mirror dodge test stood dormant, lifted his wand, and cast a lazy hex.

The ward shimmered to life. The mirror image dodged right. Dumbledore shifted his wrist. The next spell was slower, curve-angled. The ward adapted. Cassian watched the old man test it twice, three times, no haste in his movements. The mirrors responded. A slow smile tugged at Dumbledore's mouth.

"How about a duel to test the room?"