A ring of candles floated around the center of the Great Hall, and every student's attention locked onto the platform.
Melvin timed his arrival perfectly and stepped into the side chamber off the hall. He hadn't even had the chance to greet everyone one by one before he spotted Snape—robes flowing, expression blank, eyes cold—standing against the wall. Nearby, the other core-subject professors nodded and smiled, all wearing expectant looks, like coworkers enjoying a holiday while watching someone else get stuck working.
Remus Lupin was there too, right in the middle of his full-moon cycle. He waited in a corner looking pale, and when he saw Melvin, he still managed to force a gentle smile.
The elective-subject professors took up the other side of the room—Professor Babbling, Professor Vector, and Professor Sinistra, all smiling brightly. Trelawney was the only one missing, probably hiding somewhere with a bottle.
The students had already gathered. The space around the platform was split four ways—each House claimed a quadrant, with Gryffindor and Slytherin kept far apart.
Melvin did a quick headcount. All seven year groups—almost the entire school—were present.
"One unlucky first-year caught a cold and is stuck in the dorm," Flitwick said with a shrug. "And a fourth-year boy tried to use the Levitation Charm to make himself fly—broke both legs and a few ribs. Other than that, everyone's here."
He tipped his head toward Melvin. "So… let's see what you've got."
"Let's begin," Melvin said.
He carried a small suitcase up onto the platform and swept his gaze across the room. The young professor didn't look particularly stern, but his deep, pitch-black eyes brought the hall to silence almost instantly.
"Hello, everyone. I'm Melvin Lewinte. I'm sure you've heard already—tonight's lesson is about the Patronus Charm."
"Just two weeks ago, the Gryffindor and Slytherin teams played a match in the middle of a storm. We all saw an intense, exciting game… and then Dementors entered the school, roaming freely over the pitch."
"Their fog made the weather even worse. A close encounter caused Seeker Harry Potter to pass out, and in the end Gryffindor lost the match."
"And this wasn't the first time Harry lost consciousness. The same thing happened on the Hogwarts Express."
Melvin's opening was slow and heavy, building a kind of grim tension. Students felt their stomachs tighten.
"Professor—" Harry raised his hand, trying weakly to defend himself. "You don't have to emphasize the passing out. And I wasn't the only victim."
The moment the words left his mouth, he regretted it. Nearly the whole school turned to stare—some with curiosity, some with amused teasing, and the Slytherins with open contempt.
And there was also Ravenclaw's Seeker with the East Asian features—Cho Chang.
Harry felt his cheeks heat up.
"Yes," Melvin said evenly. "Any one of you could be attacked."
He set the suitcase down, tapped the clasps, and the black leather case opened—top and bottom—revealing an interior that looked impossibly deep and dark.
Icy white fog spilled out like stage dry ice—except there was no princess in the mist. There was only a tall, thin figure in a black cloak and hood, all gray and shadowy, like something that belonged in a dim attic.
Faced with a crowd of lively students—especially students who'd inhaled a trace of Euphoriant Elixir—the Dementor reacted like a starving prisoner catching the scent of the best meal in the world. It trembled with excitement.
But fear of the young professor held it in place. It hovered without daring to lunge, only drawing in deep breaths as if tasting the air. The sound rasped loudly through its throat—wet and guttural—and it made everyone's skin crawl.
The entire hall sucked in a collective breath.
A real Dementor.
The fog drifted to the walls. The warm, comfortable room suddenly felt invaded by cold. Professor Sprout rubbed her arms, goosebumps rising. "That's a boggart pretending to be one… right? Why does it feel so real?"
"It should be… right?" Flitwick said, suddenly uncertain.
Professor McGonagall pressed her lips together without speaking. The cheeriness from the potion was fading now, and her expression had turned grim.
"A dark creature born on the isolated islands of the North Sea," Melvin said gently, his voice soft enough to blunt the panic the creature inspired. "The despairing guards of Azkaban: Dementors."
"Some of you have heard of them. What you're seeing is an extremely realistic approximation—created by a boggart donated by Professor Lupin for Defense Against the Dark Arts. Given a boggart's nature, you can assume this will simulate something very close to the real thing. I want you to learn how to defeat it through training."
"What kind of training?" someone called.
"Is it the Patronus Charm?" George and Fred chimed in back-to-back, dutifully playing hype-men.
"Yes," Melvin said with a nod and a faint smile. "The Ministry refuses to reduce Dementor security. They agreed not to let them approach Hogwarts, but considering these are dark creatures driven by instinct, accidents can happen at any time."
"Headmaster Dumbledore and the staff sincerely hope every one of you has the ability to protect yourselves."
Students grew a little tense, but they listened even more closely.
"Many scholars in the wizarding world insist only 'pure-hearted' wizards can cast a Patronus," Melvin continued. "The most famous example is the Dark wizard Raczidian. When he tried to use the charm, it backfired—he conjured maggots that consumed him."
He paused, then his tone turned suddenly lighter. "However, that story is misunderstood. That Dark wizard was from Birmingham and had a thick accent. He mispronounced the incantation—same idea as that genius who tried the Levitation Charm and somehow summoned a bison."
The Great Hall erupted in laughter.
"In reality, Dark wizards struggle with the Patronus for a simpler reason: their souls are twisted. Their personalities run to extremes. They're irritable, volatile, and they have a hard time digging up genuine happy memories."
"Can you imagine a Death Eater laughing from the heart—rather than doing that cruel, nasty cackle?"
More laughter rolled through the room.
For the next half hour, Melvin covered the theory behind the Patronus Charm. He pulled funny examples from different sources and mixed in a few stand-up style beats that kept the room laughing nonstop.
"Based on ancient woodcuts and scrolls, we know the Patronus has been used for thousands of years," he said. "It's truly an ancient branch of magic."
"Listen carefully to the incantation: Expecto Patronum. It literally means you're calling for a protector."
"But there's another way to understand it," Melvin said, his voice echoing through the hall. "The caster is the protector. You cast with the intent to protect, and you bring a good memory to the front of your mind."
"That memory is exactly what a Dementor tries to steal. It's what you're fighting to protect."
Students took it in, visibly getting something out of it.
Even the professors listening in looked intrigued, like they'd just gained a new angle on a spell they'd known forever.
"Expecto… Patronum?" Snape drifted despite himself, remembering the green-eyed girl he'd met in the park—how her eyes tilted slightly when she smiled. Was that why his Patronus had changed?
Once the theory ended, everyone pulled out their wands to practice—professors included. The older staff moved through the groups, correcting sloppy wand movements and "no-I-don't-have-an-accent" pronunciation.
Thin threads of silvery mist began to appear across the Great Hall. The floating candles and the stars and moon on the enchanted ceiling seemed dimmer in contrast.
"Cast with the intention to protect… remember something happy," Ron muttered impatiently. People all around him were producing silver mist, and his wand still did nothing. He looked like he wanted to split his own head in half.
Sure, Harry and Hermione had taken extra lessons—but why was Neville progressing so fast too?
And Seamus and Dean—both their wand tips were glowing.
This spell felt downright unfair. How was anyone supposed to think about that many things at once? When ancient wizards invented magic, couldn't they have made it simpler?
"Relax," Hermione called from nearby. "Figure out what you're trying to protect."
"How am I supposed to know what I'm trying to protect?" Ron shot back. "Does the silver Sickles in my pocket count?" He pulled out a few coins, and weirdly, he did seem to find a rhythm—his casting immediately looked smoother.
"Don't be so shallow. Something more important—" Hermione guided him, sounding like she was teaching more than teasing. Detention copying had been exhausting, but she'd learned a lot. "Like your friends. Think about Scabbers!"
"Scabbers?"
"Think about all the good times Scabbers has been with you. If a Dementor attacked Scabbers, how would you protect him?"
"Expecto Patronum!" Ron said clearly, with real force.
He slashed his wand through the air. Magic surged into the willow wood; the wand tip flared, and the unicorn hair core responded to that intent to protect.
A thin, crystal-like filament of mist appeared—like autumn morning fog, light and lively. It drifted from the wand, circled Ron twice, and dissolved.
"Merlin's beard! I did it—I learned the Patronus Charm!" Ron said, thrilled. "I get it now. I have to protect Scabbers. I have to think about my happy memories with him!"
"You could think about something a little more important," Harry said, watching the whole thing and feeling like something was off. "Like family or friends, you know what I mean."
"Those people are stronger than Ron," Hermione said with a sweet little smile that didn't quite match the ruthlessness of her logic. "They don't really need his protection. A small pet is better at triggering that protective instinct. And if Scabbers can help, he'd probably be happy to."
Silver light flickered everywhere. Every so often, McGonagall demonstrated—her Patronus leapt above the crowd, a lively tabby cat.
Lupin claimed the kids needed guidance closer to their current level, and Snape—shockingly—agreed. Seeing that, the other professors also chimed in, and most of them stuck to conjuring a simple cloud of silver mist rather than a full animal.
"Expecto Patronum—" Harry tried again, but the silver glow at his wand tip sputtered out.
He glanced around. Everyone nearby stayed focused, waving wands and muttering the incantation. Seamus and Dean were basking in the growing mist they'd produced, grinning wide—both the potion and the sense of achievement working together.
Older students looked even sharper. Between tonight's clear explanation, the hands-on coaching from professors, and the boost from the Euphoriant Elixir, they were already brushing up against the spell's core idea.
A few top students—Cedric, Percy—slowed down and started noticing a problem: the silver light stopped getting stronger, but the mist still wouldn't condense into a solid form. Beyond technique and knowledge, it required a shift in mindset.
You had to face a Dementor directly to feel the real danger—and to understand happiness and protection on a deeper level.
But the professors were still circulating and guiding, and only a tiny number of students seemed ready for practical testing. Most were still at the basics; they weren't fluent enough in the theory and mechanics yet.
So there probably wouldn't be hands-on practice any time soon.
That was when Harry saw Hermione standing alone outside the practice ring. She watched others, clearly wanting to step in and help—but worrying she'd annoy them. Her expression was conflicted.
Harry relaxed for the first time all night. He stopped practicing and wandered over. "Hermione—these last few weeks, you've been copying all that Patronus research. Do any of those books say why Professor Lewinte's Patronus is a horned water serpent?"
Hermione turned and stared at him. "Didn't you read the book? How do you not know this?"
"The one Professor Lewinte recommended over the summer? I did read it," Harry said, frustrated. "That's why I'm confused. It says Patronuses are supposed to be normal animals with no magical powers. So why would someone's Patronus be a magical creature?"
"It's in the materials you copied!" Hermione said, rolling her eyes. "You just didn't read them carefully."
Her scolding had real bite, but Harry let it slide almost immediately. Professors recommended piles of reading. Apart from Hermione, he'd never met anyone who actually read all of it—let alone memorized it.
At this point, if you didn't understand something, you asked Hermione. That was basically the unspoken rule of third year. "Know-it-all" had stopped being just a joke and started sounding like genuine praise.
"So why is it?" Harry asked honestly.
"Most witches and wizards get common animals," Hermione explained patiently, straight from the text. "But a very small number get magical creatures. In history, Andros once conjured a giant Patronus. And among living witches and wizards, the most famous example in Britain is Headmaster Dumbledore's phoenix Patronus."
She continued, "Now there's another case: Professor Lewinte's horned water serpent."
"Do you think ours could be something special too?" Harry asked with a hopeful grin.
Hermione paused, then realized what he meant. She thought it through and answered carefully. "Dumbledore's phoenix is tied to something special in the Dumbledore family line—and he has Fawkes in his office. That's an actual phoenix."
She shook her head, looking a little deflated. "Professor Lewinte is connected to horned water serpents. You've seen it—Jorm has been with him since it was little."
Harry couldn't hide his disappointment. He wanted a Patronus that impressive too.
The Great Hall buzzed with energy. Candles floated overhead, and the silver light made the ceiling's sky seem brighter. Harry went back to the boring repetition of practice. Maybe the potion was helping—watching that pretty silver mist spill from his wand slowly lifted his mood again.
Even if he couldn't get a flashy magical-creature Patronus, at least he could learn to drive off Dementors and stop passing out the second one got close.
Then, out of the corner of his eye, he caught a heavy, dark stare—Snape. Harry calmly looked away, stepped forward a bit, and positioned Neville's broad frame between them.
He didn't know why, but lately Snape seemed to be paying special attention to him.
Harry figured Snape wasn't satisfied with Slytherin's Quidditch advantage and wanted a chance to dock Gryffindor points—enough to erase the fifty-point lead Neville had earned.
Harry wasn't a first-year anymore. After two years of lessons learned the hard way, he knew the best strategy was simple: stay away from Snape and don't give him an opening.