Late that night, the Great Hall was dim and warm with the collective breathing of five hundred students spread across every inch of floor. Sleeping bags and makeshift pallets covered the space between the house tables. No one was being sent back to their dormitories until every corridor had been cleared.
Dumbledore stood near the staff entrance, talking quietly with Filch and Snape.
"Astronomy Tower and Owlery are clean," Filch said. "Nothing."
"Third floor and the dungeons are clear," Snape added. His voice was precise and clipped. "Nothing in either."
"Thank you both." Dumbledore nodded, though his expression remained troubled.
Filch shuffled off to continue the sweep. Snape stayed.
They walked slowly through the rows of sleeping students — or students pretending to sleep.
"One person enters Hogwarts without a trace," Snape said quietly. "Doesn't that concern you, Headmaster? I mentioned this at the start of term — about the professor you've seen fit to hire —"
"Severus." Dumbledore's voice was gentle but final. "No member of this faculty let Sirius Black into the castle."
"I'm confident of that. Once the search is complete and the castle is clean, the students return to their houses."
"And Potter? He should be warned."
"My other star student has already briefed him." A dry note in Dumbledore's voice. "Harry knows. Now we simply hope Sirius doesn't do anything foolish before the truth comes out."
He glanced across the room at Harry — whose eyes were very carefully closed, whose breathing was very carefully steady.
Dumbledore said nothing further on the subject.
Harry lay still for a long time after they moved on.
Snape suspects Lupin. He turned it over. But why?
He liked Lupin. More than any professor he'd had, probably. The man had been their parents' friend, had shared stories freely and warmly, had treated Harry like a person rather than a symbol.
But Sirius had been their parents' friend too. If Lupin and Sirius knew each other — and they must have, going back that far — then maybe Lupin knew what had really happened. Maybe he was the way to Sirius.
Harry opened his eyes in the dark and stared at the ceiling.
He had to talk to Lupin.
Morning. The martial law lifted with the castle declared clear.
Harry gathered Kevin and the others before breakfast and laid it out — what he'd overheard, what he'd pieced together.
"Lupin knows Sirius. Snape wouldn't suspect him otherwise. If Lupin let him in, they've been in contact. He could lead us to Sirius."
"Dumbledore said Lupin wouldn't have let Sirius in," Kevin pointed out.
"We still need to ask." Harry was immovable.
Hermione said, carefully, "This all works if Sirius isn't the traitor. But if he is, and Lupin let him in anyway —"
She let it hang.
Harry went quiet. The logic landed. Doubting Lupin from that angle meant doubting someone they'd all grown to genuinely like over the past several months.
He rejected it.
"Dumbledore trusts him," Harry said finally. "And I trust Dumbledore. We go to Lupin, ask him directly, and see what he says."
"Defence Against the Dark Arts is this afternoon," Kevin said. "We'll catch him after."
He was curious himself. The story he remembered had skipped the backstory almost entirely — Sirius and Lupin in that shack, talking fast and loud and assuming everyone else already knew. There was a lot he didn't actually know about what had happened twelve years ago.
Defence Against the Dark Arts. Except Snape walked in.
He moved with purpose, snapping his wand at each window as he passed to slam the shutters. The room darkened. He yanked the curtain closed over the remaining light.
"Page three hundred and ninety-four," he said, without preamble.
Nobody moved.
"Professor Snape?" Harry said. "Where's Professor Lupin?"
"That is not your concern, Potter. Professor Lupin is indisposed." He aimed his gaze at the room. "Page three hundred and ninety-four. Now."
Kevin opened his book. Werewolves.
Hermione got there first, composure intact. "We've just finished Red Caps and Hinkypunks. Skipping ahead seems —"
"There are wolves in the school," Kevin said quietly. "It's relevant."
Snape's gaze cut to him. "Quiet."
"Who can explain the difference between an Animagus and a werewolf?"
Hermione's hand went up immediately. Snape looked past her.
"Kevin."
Hermione lowered her hand. She pinched Kevin's side.
"Ow —"
He rubbed his ribs and stood up.
"An Animagus transforms by choice into a fixed animal form. Full control — timing, duration, the transformation itself. A werewolf has none of that. The change happens at the full moon whether they want it or not. They lose themselves entirely."
"There are two kinds," he continued. "Pure-blooded werewolves — full-time wolves with some pack intelligence, capable of spreading the curse. The Ministry hunted most of them down. A handful are left, possibly in the Forbidden Forest."
"The second kind are the transformed — people who were bitten or scratched and infected. In human form, they're fully themselves. At the full moon, they change without control. The curse passes. But Wolfsbane Potion, taken before the full moon, lets them keep their mind during the transformation. Not safe exactly, but manageable."
He sat.
"Correct," Snape said. One word, delivered like a receipt. "With one addition — a werewolf is dangerous before the transformation begins. Remember that."
The lesson continued. Origins, physiology, identification, legal classification. Dry material, delivered with Snape's characteristic efficiency. The bell went.
"Monday. Two rolls of parchment. Identifying characteristics of werewolves and methods of detection."
Students groaned as Snape swept out.
Hermione was on Kevin before the door had fully closed.
He pulled her and Harry aside, into a quieter corner of the corridor.
"Lupin is infected," Kevin said. "Werewolf — the bitten kind."
"How do you know?" Harry asked.
"Snape as good as told me at the start of term. Then I caught the smell of Wolfsbane on Lupin early in the year. Snape's been watching him since day one. Last night was the full moon — Lupin's out sick today." He looked at them. "Put it together."
Hermione had reached the same conclusion two minutes into the lesson. She nodded slowly.
Neither of them was afraid of Lupin because of it. He was the same person who had been kind to Harry, who had taught them with patience and wit, who had spoken of James and Lily with warmth that was clearly real. The werewolf part was a medical fact, not a character indictment.
"Give it a few days before we go to him," Kevin said. "The shift takes it out of you. He needs to recover. Watch the Quidditch match in the meantime — it's tomorrow."
Harry nodded. He could wait.
---
---
You already know the mission. My friend doubted this community and we are still making him regret it.
One Powerstone vote. One review. That is all it takes to keep proving him wrong.
Top 10 is non negotiable. Let's make it happen.