The first Defense Against the Dark Arts class of the term began that afternoon.
On his way to the classroom, Sean passed a group of Gryffindor students who were busy trying to fend off Peeves' pranks. He, on the other hand, made his way through without trouble and took a seat in the middle of the room.
Peeves rarely bothered the Slytherin students — the Bloody Baron, Slytherin's house ghost, was the only thing Peeves was truly afraid of. That alone was enough to keep the poltergeist from pestering Slytherins too much — he had no interest in being chased by the Baron for causing trouble.
Sean settled in next to Blaise. Before long, Lupin walked in. He glanced at the class, gave a faint smile, and said, "Good afternoon. I see many of you came early — and prepared your parchment and quills. But you won't be needing those today. Put them away, please, and pack up your books too. We're having a practical lesson."
Heads lifted all around the classroom — Sean included.
Lupin still looked shabby, with threadbare robes that were patched at the sleeves, but he seemed healthier than before. Maybe the warm meals and rest at Hogwarts were already doing him good.
No matter which House they were from, the Hogwarts students were always more excited about practical Defense lessons than long lectures — so long as it wasn't another ridiculous performance like Lockhart's.
The students who'd already settled in got up right away, shouldered their bags, and followed Lupin out of the Defense Against the Dark Arts classroom in a lively, eager line.
"Professor, where are we going?" someone asked.
"To the staff lounge. What we need for today's lesson is waiting there," Lupin replied simply.
He didn't explain further, just led the group down the corridor. They hadn't gone far when they came across Peeves, who was gleefully stuffing a wad of gum into a door's keyhole.
The moment Peeves spotted Lupin and the line of students behind him, he broke into a sing-song chant, each line drawn out mockingly:
"Lupin, you lunatic, you fool— Lupin, you lunatic, you fool—"
Hovering overhead, Peeves danced about, delighting in his little show. Lupin stopped, raised a hand for the students to wait, then calmly pulled out his wand.
"This is a handy little charm," he told the class with a mild smile. Then he called up to Peeves, "Peeves, that gum will just give poor Mr. Filch more work to do. Allow me to help you get rid of it."
He flicked his wand. "Wadiwasi!"
The gum shot from the keyhole like a bullet — straight into Peeves' nostril. The poltergeist let out a squeal of surprise, flipped backward in midair, and zoomed off down the corridor, hurling muffled curses over his shoulder.
For most Hogwarts students, Peeves was an endless nuisance — and seeing a teacher handle him so easily won Lupin immediate respect. The class fell in step behind him again, whispering among themselves, their wariness of him already starting to shift.
Two corridors later, Lupin led them into the staff lounge. Inside, Snape sat waiting. The moment he saw Lupin enter — surrounded by students — his expression darkened like a thundercloud. He rose without a word, brushing past Lupin as though he didn't exist.
But when he reached Sean, his sharp glare softened just a fraction. He paused and muttered, "How's the work going on the substitute for the second ingredient?"
Sean answered quietly, "We've made some progress, Professor."
"Good. Keep at it. I want a working substitute by next weekend."
"Yes, Professor."
With that, Snape gave Sean a curt nod, then swept out of the lounge, his robes swirling behind him as the door swung shut.
Lupin glanced after Snape as he left, then turned to Sean with a faint smile."Your name's Sean, right? We met in Severus' office on the first day of term."
"Yes, Professor."
Sean could tell that Lupin genuinely wanted to get to know him — maybe because he'd noticed Snape's unusual attitude toward him, or maybe he'd heard something through the grapevine. But Sean himself had no real interest in making friends with Lupin.
Before he could say anything else, Harry jumped in. To him, Sean wasn't just another Slytherin — he was a good friend, and Harry felt Lupin should know that."Professor Lupin, Sean's someone Professor Snape really trusts. He even published papers in The Golden Crucible during his first and second years — he's brilliant at Potions!"
Lupin's eyebrows rose in surprise. News of Sean's publications had spread around Hogwarts long ago, but Lupin, living hand-to-mouth as he did — and fighting to keep his condition in check — hardly had time or money for academic journals. Most days, he could barely afford necessities, let alone the latest magical research.
Hearing this now, he looked at Sean with newfound respect."I had no idea we had such a talented student among us. I hope I'll see that same dedication in Defense Against the Dark Arts."
"I'll do my best, Professor," Sean answered politely — but kept his tone distant.
Lupin seemed to pick up on it but didn't let it bother him. He simply turned back to the rest of the class."Right, everyone — follow me."
He led them to a large, old wardrobe tucked against the far wall. It rattled suddenly, banging once against the wall behind it, as if something inside was eager to get out.
A few students shrank back nervously. Lupin held up a hand, reassuring them with calm authority."No need to worry — there's a Boggart inside. They love dark, enclosed spaces, especially ones with a bit of history. Today's lesson is all about handling Boggarts. So — let's have a look at what frightens us most, shall we?"