"Let me explain," Professor Lupin said slowly.
"The Patronus Charm is one of the most famous spells in existence, and also one of the most powerful defensive charms…
It's an extremely complex and difficult spell that summons a semi-corporeal positive force—a Patronus.
It can repel Dementors and Lethifolds, creatures for which there are almost no other defenses."
Lupin clearly knew the subject well. His voice remained gentle as he continued:
"However, the vast majority of witches and wizards are completely unable to produce any form of Patronus…"
"What do they do when they face Dementors then?" Ron asked.
Lupin was quiet for a moment, then shook his head lightly.
A chill ran down the students' spines.
If Sean hadn't summoned his Patronus earlier, what would that Dementor have done to them?
Even worse—they had been completely powerless to fight back.
"Can I learn it?" Hermione asked suddenly. "Professor Lupin?"
After eating some chocolate, she seemed to have warmed up considerably to the professor who used to run the bookstore.
"The Patronus Charm is widely regarded as advanced magic, well beyond ordinary wizarding level, Miss Granger.
The spell is particularly deep and incredibly complex. Many experienced witches and wizards struggle with it.
Even summoning a non-corporeal Patronus is considered a mark of exceptional magical talent."
Lupin didn't answer Hermione's question directly. Instead, he phrased it in a way that made her lower her head slightly in thought.
"What about Sean? I saw… a cat?" Ron asked, scratching his head.
"Mr. Green…" Lupin said with clear admiration. "Forgive me, but Mr. Green is the most gifted wizard I have ever encountered.
I can scarcely imagine any wizard producing a corporeal Patronus at his age.
In all my years, I've never seen anyone manage it."
"Oh, of course. That's just Sean…" Ron nodded in complete agreement.
Lupin glanced around the compartment and saw that nearly every student wore the same expression of total certainty.
It caught him a little off guard.
"Anything you think is impossible," Ron said with feeling, shrugging, "just put Sean's name in front of it and it becomes a fact."
"Is that so?" Lupin smiled.
"You'll find out soon enough, Lu—"
"Lupin."
"Professor Lupin," Ron corrected in that wise-beyond-his-years tone that made everyone smile faintly.
A loud whistle blew. The train finally pulled into Hogsmeade station.
Everyone piled off in a chaotic rush.
Owls hooted, cats meowed, and Neville's toad croaked loudly from under his hat.
The tiny platform was freezing, and icy rain poured down in sheets.
"First-years, this way!" a familiar booming voice called.
The moment Sean stepped off the train, he spotted Hagrid's enormous figure at the far end of the platform, rounding up the frightened first-years for the traditional boat ride across the lake.
"Hey! Sean!" Hagrid waved enthusiastically and mouthed something clear.
Sean knew it was a reminder to stop by his hut to discuss the first Care of Magical Creatures lesson.
After all, Sean was technically Hagrid's assistant—even while still attending classes…
Still, Hagrid wanted to go over every detail before he could relax. Sean, who had no desire to see Buckbeak back on the executioner's block, happily accepted.
A few wet splashes later, Harry and the others climbed down behind him.
As if on cue, a drawling, gleeful voice reached both Sean's and Harry's ears.
"You fainted, Potter? Is what Longbottom said true? You actually fainted?"
Malfoy elbowed his way past the first-years and blocked Harry's path on the way to the carriages, grinning from ear to ear. His gray eyes glittered with malice.
"Move, Malfoy," Ron said through gritted teeth.
"Did you faint too, Weasley?" Malfoy said loudly. "Did that scary old Dementor frighten you as well, Weasley?"
"Having some trouble?" a mild voice asked.
Professor Lupin had stepped off the train.
Malfoy stared rudely at Lupin, taking in the patched robes and battered trunk.
"Oh, no—er—Professor," he said, a faint trace of mockery in his voice.
Before he could say anything else, he met a pair of direct emerald eyes.
Sean felt a touch of amusement. Malfoy really was like Harry's shadow—always appearing the moment Harry was in trouble or embarrassed, preferably with a camera crew in tow.
When Malfoy slunk away and they climbed into the carriages heading toward the castle, Sean reflected that it all traced back to Harry rejecting Malfoy's arrogant invitation in the Great Hall years ago.
But none of that really mattered.
The Malfoy family had never managed to accomplish a single useful thing for Voldemort anyway.
Outside the castle.
The students followed the crowd up the stone steps, through the grand oak doors, and into the wide entrance hall.
Flaming torches lit the space, and a magnificent marble staircase led upstairs.
To the right, the doors to the Great Hall stood open. Sean started toward them, glancing up at the enchanted ceiling—
A stormy black sky full of heavy clouds—when a voice rang out:
"Sean—you boy—and Potter! I need to see both of you!"
Sean suddenly felt strangely small as he and a startled Harry turned around.
Professor McGonagall, Transfiguration teacher and Head of Gryffindor House, was calling to them over the sea of heads.
She was a severe-looking witch with hair pulled into a tight bun and sharp eyes behind square spectacles.
"There's no need to look so nervous—I only want a word in my office, Potter—" she told Harry, then turned to Sean.
"As for you, young man—you should be a little nervous—"
Finally, she turned back to the others and instructed:
"Off you go to the Hall, Weasley, Granger, Longbottom, and you too, Finch-Fletchley."
The students stared wide-eyed as McGonagall led Harry and Sean away from the chattering crowd.
They followed her across the entrance hall, up the marble staircase, and down a corridor.
McGonagall's office was small but had a roaring, cozy fire.
The moment they stepped inside, she motioned for them to sit. She paused beside Sean, then said abruptly:
"Professor Lupin sent an owl ahead. He told me you encountered something quite unpleasant—"