The trouble with new professors was that they often mistook novelty for authority.
That was Adrian's first thought as Potions resumed under Slughorn and the room, though physically unchanged from Snape's old domain, acquired an entirely different species of danger. The dungeons remained cold. The stone still held damp in its joints. Glass jars along the walls still floated unpleasant things in preserving fluid. But Snape had taught as if every lesson were a trap designed to reveal weakness under pressure. Slughorn taught as if the room were a stage and he a host whose guests might, if properly flattered and strategically distinguished, become worth remembering later.
Neither approach, Adrian thought, was kind.
Only one of them pretended to be.
The first sixth-year Potions lesson began with cauldrons already arranged in pairs and a large blackboard bearing the day's potion in handsome looping script:
*Draught of Living Death*
A silence passed through the room when they read it.
Not fear exactly. Recognition. Advanced enough to matter. Difficult enough to sort the merely competent from the gifted, or so Slughorn clearly wished them to believe. The potion sat there on the board like a challenge written by someone who wanted the room divided quickly and elegantly into categories.
Slughorn himself stood near the front table in robes of deep bottle-green this morning, sleeves pinned back with silver clasps that looked decorative and therefore probably cost more than was morally necessary. Six cauldrons simmered on his desk, each containing a potion at a different stage. The room smelled of wormwood, crushed lavender, old stone, and the kind of medicinal bitterness which suggests the brew in question would improve absolutely nothing in a human life while remaining academically impressive.
"Now then," Slughorn said, rubbing his hands together with visible pleasure. "Sixth-year Potions. No more childish stewing of nettles and praying over boils. We begin, as we mean to continue, with something elegant."
Ron, beside Harry, muttered, "That sounds ominous."
Hermione had already copied the title, ingredients, and first eight lines of method onto fresh parchment in a hand so exact it would have improved several lesser legal systems.
Slughorn smiled out across them.
"I imagine most of you have heard of this potion. A little masterpiece. Delicate. Exacting. Highly rewarding if done properly, less so if done with enthusiasm standing in for judgement." His eyes moved over the room with that same soft bright appetite Adrian had seen in the office. "I have, as a small encouragement, brought along a few prizes for the most successful brewers."
That improved the room's posture at once.
Of course it did.
Children remain most governable when offered distinction in manageable doses.
Slughorn lifted one hand and indicated the shelf beside his desk. A small bottle of clear golden liquid caught the candlelight and flashed.
"Felix Felicis," he said.
The room changed.
It was not loud. No gasps, no idiotic open excitement, not from sixth-years who had learned to treat public appetite as something best half-disguised. But the shift went through them all the same. Attention sharpened. Harry sat straighter. Hermione's quill stopped for the first time in three minutes. Even Draco, two tables over, looked up properly.
Liquid luck.
Useful prize.
Bad educational principle.
Slughorn, naturally, looked delighted by the result.
"Just one small bottle," he said, almost lazily. "Enough for perhaps twelve hours of very good fortune. One does not take it regularly, of course. Highly toxic in quantity. Ruinous if misused. But one evening, one exam, one particular undertaking..." He let the thought sit there just long enough to become collective temptation. "The first among you to produce a perfect Draught of Living Death wins it."
There it was.
Not instruction, then. Not merely.
Competition as architecture.
Adrian looked down at the ingredients list. Sopophorous bean. Valerian roots. Wormwood infusion. Asphodel. Standard enough for the category, though not forgiving. The method beneath it was densely written and, Adrian noted at once, faintly wrong in the way textbook methods sometimes become wrong by being too eager to survive committee revision.
Too clean. Too generalized. Built for correct average hands rather than the exact demands of the brew.
Interesting.
At the table beside him, Anthony said under his breath, "Nothing improves pedagogy like legalized gambling."
"That sounds interpretive," Adrian murmured.
"It sounds Scottish boarding school."
Slughorn clapped once.
"Off you go, then. Pairs if you like, though I warn you, partnership in Potions often reveals more about social incompatibility than romance ever does."
That drew the required laugh. Enough for cover. Enough for rooms to begin moving.
Adrian remained where he was.
Not because he had no partner. Because he preferred the room before people fully committed to noise.
Harry and Ron, after a brief chaotic consultation involving spilled notes and wounded pride, took a cauldron near the middle. Hermione, after one scandalized look at both of them, chose to work alone. Draco partnered with Zabini. That itself was useful. No Crabbe, no Goyle. No visible bodyguards, then. Only one sharp quiet boy from Slytherin House and another trying very hard not to split in public.
Adrian reached for a copy of the textbook from the stack at the side table.
The top one had gone.
So had the second.
By the time he reached the last remaining pair, he found himself with a battered copy whose spine had partially separated at the middle and whose edges looked as if three previous owners had tried to improve it by weather and resentment.
Useful.
He took it back to the table and opened it.
Inside the front cover, written in old brown ink with an irritating certainty of hand, were the words:
*This Book is the Property of the Half-Blood Prince*
Adrian looked at the page for one second longer than strictly necessary.
Anthony, glancing over, said, "That sounds unstable."
"It sounds adolescent."
"No," Anthony said. "Adolescent instability. More dangerous because it has handwriting."
The book smelled faintly of old parchment and something more specific beneath it. Dust, certainly. But also dried rosemary and old potion fumes soaked so long into the pages they had become part of the binding's memory. Human use. Repetition. Not library neglect exactly. More like long private dependence.
He turned to the potion instructions.
And stopped.
The margins were dense with notes.
Not childish doodles. Not random corrections. Layered observations in a quick slanting hand, terse enough to suggest impatience with prose and exact enough to reveal someone who had already outgrown the textbook by the time he wrote in it.
*Crush with flat side of silver knife, releases juice better than cutting.*
*Valerian should be added after 3rd stir, not before. Book wrong.*
*Counter-clockwise half turn at end to settle surface.*
There.
Not one correction. A system of them.
Adrian read the page again, first by the printed method, then by the annotated one. The differences were small. That made them worse. Major errors are easier to detect. Small ones only matter if one already knows which parts of precision create outcome.
The Half-Blood Prince, whoever he had been, knew.
Interesting.
Anthony, having begun the standard method with visible disapproval, glanced over once more. "You look as though the book has insulted you academically."
"It may have improved itself."
"That seems rude."
"It seems useful."
He set the book flat and began.
The room thickened into work.
Knives on boards. Glass rods tapping cauldron rims. Ingredients crushed, sliced, measured. Slughorn moving between tables with the genial floating quality of a man delighted by his own educational weather. The dungeons grew warmer by increments. Steam carried the scent of sopophorous bean and wormwood into every sleeve and cuff. Somewhere near the back, Seamus set his first bean on fire by force of incompetence or initiative. Slughorn called it "spirited" and removed it before the room improved the incident into legend.
Adrian ignored the printed method and followed the Prince's.
Not blindly. That would have been lazy.
He checked each note against the logic of the potion and the structure of the ingredients. The crushed bean released more juice, yes. The delayed valerian improved clarity. The counter-clockwise half turn at the end... interesting. Not obvious from theory. Only from repeated practice.
The book did not merely correct.
It remembered.
He was halfway through the third stage when Slughorn stopped at his shoulder.
"Ah," the professor said softly. "Vale."
There was no surprise in the tone. Only interest sharpened by what he saw in the cauldron.
The surface of Adrian's potion lay smooth and dark as polished slate, with the clean pale shimmer Slughorn had demonstrated in the best of the sample brews. The room around them remained full of minor failures. Harry's potion, though improved beyond Ron's by some private arrangement Adrian had not yet identified, still sat a shade too thick. Hermione's was precise but faintly overworked, as if she trusted method more than instinct and was being punished for the loyalty.
Slughorn leaned closer to Adrian's cauldron.
"Where," he asked, almost pleasantly, "did you learn that bean technique?"
Adrian looked at him.
"From the book."
Slughorn's smile thinned by one degree.
"Did you indeed?"
"Yes."
Interesting.
Not because Slughorn minded being corrected. Because he minded not being the source of it.
He straightened again with no visible break in geniality.
"Well then," he said. "One sees the old school stock still retains a few surprises."
The sentence could have meant anything.
That was why it mattered.
He moved on.
Adrian returned to the book.
Across the room, Harry was now working with unusual confidence. Not natural, not textbook, but something closer to improvisation governed by exact suggestion. Adrian looked once toward the table and saw the answer at once. Harry had an old copy too. Not the same one, but similar age, similar wear. He was glancing down into it in precisely the rhythm of someone receiving private advantage from a borrowed intelligence.
There.
So.
Two books from old stock then. Or one set copied once. Or some previous student's annotations surviving in more than one volume. The thing itself mattered less than the pattern. Hidden method inserted into official curriculum by marginal note. A private teacher folded invisibly into public lesson.
Useful structure.
Dangerous one.
Because children seldom distinguish between inherited competence and trusted intention when the results arrive fast enough.
The lesson ended in stages.
Cauldrons settled. Steam thinned. students leaned back from benches with the exhausted offence of people who had been forced to care too much about liquids. Slughorn moved from brew to brew with visible pleasure, praise distributed selectively and with enough audible contrast to preserve the educational principle of envy.
When he reached Harry, he stopped for a fraction too long.
Interesting again.
Harry's potion, aided by whatever old marginal intelligence his book contained, was excellent. Better than Hermione's. Better than Adrian's by one infuriating bright degree. Slughorn held the sample ladle up to the light, looked delighted, and declared it "perfect."
The room took that badly in all the expected ways.
Hermione went still first. Too still. Ron looked as though someone had informed him potatoes were a political fiction. Malfoy's expression altered only at the mouth, where the old contempt met something sharper and younger and closer to alarm.
Slughorn presented Harry with the tiny bottle of Felix Felicis to broad applause and selective hatred.
Harry himself looked less triumphant than bewildered.
That was almost worse.
Adrian closed the Prince's book and felt, not jealousy exactly, but a cleaner irritation.
Not at Harry.
At the mechanism.
Because the room had just been sorted not by skill, nor even by instruction, but by inheritance of hidden method. Private advantage wearing the costume of classroom merit. Very Hogwarts. Very useful. Very dangerous once boys started trusting the voice in the margins because it got them prizes faster than professors did.
As the class emptied, Hermione caught Harry by the sleeve outside the door.
"You didn't follow the printed instructions," she said.
Harry, still holding the Felix Felicis as if uncertain whether it counted as legal reality, said, "I followed the better ones."
"That is not how school works."
"That sounds statistical," Ron muttered.
Hermione rounded on him with enough force to improve his posture by one full moral category.
Adrian moved past them into the corridor, Anthony beside him.
"What have you acquired?" Anthony asked.
"A textbook."
"That sounds false."
"A person in the margins," Adrian said.
Anthony stopped walking for half a second. "That sounds worse."
"Yes."
Defense Against the Dark Arts with Snape followed after lunch.
No one entered that room with optimism.
The old classroom had changed less than Slughorn's. Snape had no interest in atmosphere beyond what authority required. Desks in rows. Blackboards clean. Dark detector instruments removed or hidden. The room smelled of chalk, polished wood, and the faint medicinal sharpness of old spellwork lingering in the walls.
Snape stood at the front in absolute black.
If his appointment to Defense pleased him, he had concealed it under enough control to count as hostility. The class looked at him with the collective expression of people forced into weather they had previously only discussed theoretically.
Snape let the silence build.
Then said, "You will open your books."
No welcome. No pretense.
Useful.
The text for the term concerned non-verbal spellcasting.
There was a brief general unhappiness at that.
Not panic. Sixth-years had learned not to give professors certain satisfactions too openly. But enough.
Snape saw it all.
"Incantations," he said, moving along the front row with his hands clasped behind his back, "are a crutch. Useful for the stupid, the tired, and the theatrically inclined. But a wizard who cannot direct intention without announcing it in advance should not be surprised when his opponent profits."
The room held that in resentful silence.
Harry, Adrian noticed, had already shut half a degree inward. Not afraid exactly. Preparing for abrasion.
Snape's gaze passed over the class and paused, ever so slightly, on Draco.
There.
The smallest of things.
But real.
Not favoritism. Not public concern. More like a check against a line previously drawn in private.
Draco sat straight and gave nothing back. Too straight, perhaps. His face remained composed. His hands did not. One thumb kept moving once against the side of his wand under the desk, rubbing the wood in tiny repetitive strokes as if continuity had to be maintained by touch.
Snape began with demonstrations.
The room did not improve.
Neville, mercifully absent from sixth-year Ravenclaw and Slytherin company, could not be destroyed by it here. Instead the class discovered all the newer, more sophisticated ways intention could fail when stripped of speech. Wand movement remained. Focus remained. But the final alignment between will and release, that last precise click of internal certainty, proved elusive in almost everyone.
Harry's first shield attempt failed cleanly enough to earn only a look.
Ron's produced a burst of sparks so apologetic they might have counted as social embarrassment made visible.
Hermione improved fastest, which annoyed both herself and Snape by separate routes. She hated not mastering it at once. Snape hated visible competence arriving from the child most likely to question his educational philosophy at the end of the hour.
Draco's non-verbal jinxes worked.
Not elegantly. Not consistently. But they worked often enough to matter.
Interesting.
Because boys under strain usually lost precision first. The fact that Draco retained it here suggested either private practice or pressure severe enough to concentrate rather than scatter. Neither possibility made Year Six kinder.
Snape stopped once beside his desk and said, too low for most of the room, "Again."
Draco obeyed at once.
The next curse landed sharply and without visible difficulty.
There.
Private line confirmed.
Not merely House favoritism then. Coaching. Specificity. Some older route of instruction carrying through the public lesson.
Adrian felt the room's architecture alter by degrees while everyone else remained occupied with their own failures. Slughorn selected by appetite. Snape instructed by pressure. Harry had acquired a hidden textbook voice more useful than the printed curriculum. Draco had some private line into competence and looked none the happier for it.
Hogwarts, as ever, was teaching more than one class at once.
By evening the school had already absorbed the day and begun redistributing it as story.
Harry winning Felix Felicis. Hermione unimpressed by hidden instruction. Snape "worse in Defense than expected," which Adrian considered statistically difficult but emotionally understandable. Slughorn's little invitations apparently real, not rumour. Ginny Weasley heard laughing with someone near the stair about betting pools for who would be asked first.
Ravenclaw Tower smelled of rain-damp cloaks and fire.
Anthony sat upside down in one chair, which no longer seemed worth challenging as a social choice, and said, "So. Which educational model ruins us first? Predatory favoritism or militarized contempt?"
"That sounds interpretive."
"It sounds first week."
Michael, working already at an essay as if by speed one might escape education, said, "Potter won Felix Felicis."
"Yes," Adrian said.
"That seems catastrophic."
"It seems Hogwarts."
That made Anthony laugh.
Adrian took the Prince's textbook to the window alcove later and opened it again under the lamp.
The handwriting changed across chapters.
Not dramatically. Same hand, same impatience, same habit of compressing letters when the writer moved quickly from irritation to precision. But the mood altered. Some pages held only corrections. Others, little remarks almost personal in their confidence.
*Ignore this, if you enjoy mediocre results.*
*Counter-curse easier than listed if cast low and late.*
*Professor V. knows nothing of practical use.*
There.
Not only Potions notes then.
The book had lived with its owner long enough to become a room for him.
Or her.
No. Him, Adrian thought. Not from logic. From tone. Which was not evidence and therefore irritating.
The Half-Blood Prince.
Ridiculous name.
Useful mind.
Potentially dangerous intimacy.
Because the thing about voices in margins was that they arrived without the social friction of actual people. No face. No demand. No visible claim of authority except the one competence produced. Children, especially lonely or pressured ones, trusted that kind of voice too quickly because it asked for belief only after proving value.
Harry would like it.
That was the problem.
Not because Harry was stupid. Because Harry was practical. If the book improved outcome, he would continue using it until given a compelling reason not to. Hermione would resist on principle. Ron would admire results and avoid theory. Draco, Adrian suspected, would hate the whole arrangement on instinct if only because it gave Potter private advantage by a route he himself had not controlled.
The room behind the margins remained closed.
That made Adrian want it more.
He turned to the inside cover again and looked at the words there.
*This Book is the Property of the Half-Blood Prince*
Property.
Not name. Not signature. Not ordinary school claim.
Title instead.
A room chosen around the self.
He opened his notebook and wrote:
Public curriculum now split by hidden voices.
Prince notes improve outcome too reliably to count as childish vanity.
Danger lies not in one good potion, but in borrowed authority becoming trusted.
Then, after a moment:
Children prefer private teachers who never demand identity.
That line sat badly with him once written.
Because it was true too widely.
He closed the notebook.
Outside, rain moved over the dark grounds in slow silver bands. Somewhere in the distance, a door shut. A staircase shifted. The castle arranged itself around the year with all its old bureaucratic patience.
The Half-Blood Prince, whoever he had been, had entered the school again not by body but by method.
And Hogwarts, as always, was more than willing to teach children through structures no adult had admitted building.
*End of Chapter 82*