Ch26- Mind Magic - Harry Potter and the Surprisingly Competent History of Magic Professor - NovelsTime

Harry Potter and the Surprisingly Competent History of Magic Professor

Ch26- Mind Magic

Author: TheFanficGOD
updatedAt: 2025-08-09

Rest of the summer passed in a slow, predictable crawl.

Cassian kept to himself. He did the polite thing. Turned up to breakfast, nodded at the right relatives, spooned marmalade onto toast like he wasn't planning to throw himself into a cliff the next time someone mentioned "blood purity." He let the jabs roll off. Rosier cousins circling like bored vultures, offering comments to be noticed but too polite to challenge. He smiled through it all, eyes glazed, like a man pretending to care about tomorrow's shipping forecast while planning murder.

Once that was over, he slipped into his room and shut the door. A neat stack of volumes waited. Legilimency here, Occlumency there, dense theory, no hands-on guides... yet.

Turned out these books weren't exactly available to the public. Perk of being a Rosier, though, entry to the kind of library most curse-breakers had to bleed for. There were no safety sections. No tidy labels. Just walls of leather-bound tomes and the faint sense that something in the corner was breathing.

He ran a hand down a shelf marked "Cognitive Magicks - Secured," fingers brushing against spines with titles like The Mind's Looking Glass, The Art of Mental Shielding, and, somewhat worryingly, How to Break a Mind Without Leaving Bruises. Comforting stuff. He plucked the first two out and tucked them under one arm.

Finally. Something useful. Something that didn't involve which Rosier cousin was courting whom or what grand-uncle had hexed which Ministry owl for flying too low. Just clean, well-documented, ethically grey mind magic.

He slumped into the old armchair by the hearth in his room, legs half-draped over the armrest, and cracked the first one open.

About six pages in, he realised something important, this wasn't entry-level stuff.

Legilimency wasn't just waving your wand and peeking into someone's head like rifling through their sock drawer. It was layered. Vicious. Personal. Occlumency was even worse. That was locking your own thoughts in a vault and daring someone to break in. And if they did, gods help them. Some of it involved breathing techniques, others, anchoring your thoughts so deep in memory that nothing could shake them. The real twist though, not everyone could even do it. You needed a particular talent, a kind of internal tuning fork. Magical aptitude. Psychic receptivity. Whatever you called it, this body didn't have it.

Didn't matter how clever he was in his past life. No amount of reading dusty tablets or diagramming proto-Sumerian epics prepared your brain for magical resonance. If anything, too much thinking got in the way.

So he didn't try. Not seriously. No foolish experiments. No "accidentally" breaking into Towel's thoughts while asking for more bathwater. He just studied. Learned what not to do. Like avoiding eye contact with anyone mildly suspicious.

Because eye contact... well, that was apparently a trap.

Turns out, you stare at someone too long in this world, and you might end up broadcasting your deepest shame like it is on the Hogwarts notice board. Or worse, if they knew what they were doing, they might go digging.

That wass when the memory hit him. Like a shiver running up his spine, pulling him back.

Snape. Dumbledore. Both of them.

He looked them straight in the eye. Bathsheda said something to him back in Norway.

Somewhere between the rune pit and the ministry checklists, "This stuff is mad," he muttered once, scrawling a note in the margin that read, Do not attempt on elf. Or self.

Bathsheda, who had just returned from arguing with a frost-spiral about its symmetry, barely looked up from her cup of tea. "Of course it is mad. Why did you think no one teaches it casually?"

Cassian raised a brow. "You say that like you speak from experience."

She sipped. "Snape once tried to break into my head."

His hand froze mid-turn on the page. "Sorry, what?"

"Tried," she repeated. "Didn't succeed."

Cassian blinked. "You dueled Snape. In your mind."

She lifted a shoulder. "We were both young and argumentative. He thought I was hiding something. I was. It wasn't his business."

He stared. "Did he apologise?"

Her smile at the time still sent shivers down Cassian's spine. "Oh, he regretted it all right."

She said it like she was discussing tea brands, but something in her eyes had shut the conversation down right there. He didn't ask again.

Now, back in his room, shirt half-buttoned, sleeves rolled sloppily to the elbow, Cassian sat at his desk, tapping a quill against his jaw. The book on Occlumency lay open beside him. He stopped reading three pages in.

The thought wouldn't leave him.

Snape and Dumbledore were Legilimens. Not just rumoured... he knew. Well, she knew, and she didn't usually throw that kind of thing around unless it was true. He trusted her more than most books anyway. Which was saying something.

So. Snape. Dumbledore. Both had looked him in the eye.

And what did that mean?

If they looked and really looked... right down to the scaffolding of his thoughts, surely they would have known. He wasn't Cassian Rosier. Not the original, anyway. His soul, or whatever counted for it, was borrowed. Imported. Slightly scorched on arrival, perhaps, but functioning.

And if they seen that?

Well... Dumbledore might've said nothing. Probably would have kept it as a nice trivia until he needed something from you. The man was about as readable as a locked tomb. Could stare into your soul and offer you a sherbet lemon in the same breath.

But Snape?

Snape didn't strike him as the type to sit quietly while a stranger walked around wearing a pure-blood's skin like it was on sale at Madam Malkin's. If Snape had really seen it, there would have been wands, fire, maybe a pithy insult before something exploded.

Cassian sat back, rubbing the heel of his palm over his eyes. "Unless," he muttered, "they didn't see anything at all."

He pieced together a few theories a couple weeks later, after ploughing through every book in the Rosier library that even sniffed in the direction of brain, soul, memory, or magic. He torn through titles like Warding the Self: Personal Memory in Magical Minds and The Thought Knot: Why You Can't Just Think Harder. Thrilling stuff, written by people who probably hadn't laughed in decades.

First theory... his favourite because it was just plausible enough to be horrifying, his soul wasn't from this world, so the memories, his real ones, were stuck behind some kind of magical firewall. The body might be Rosier, but the soul definitely wasn't. Which meant the eyes weren't exactly the original model, and memory magic often worked through soul-imprint recognition. No proper imprint? No access. Like trying to open a vault with someone else's fingerprint.

Second... equally grim, but in a way that made him feel slightly more smug, that "interface" in his head, the thing that had first flared up when Lumos failed and then handed him Lumos Noctis like it was a Christmas gift, might be doing more than just feeding him spells. It was shielding him. Protecting its secrets, and by extension, protecting him. Maybe it was sentient. Maybe it just didn't fancy Ministry dogs poking about. Either way, it knew what it was doing.

He made a note…

System = magical condom for soul? Investigate further (Never say this aloud. Ever.)

Third... he wasn't fully... integrated. He dropped into this life like someone leaping onto a moving carriage. The original Cassian was mostly gone, sure, but maybe not entirely. Maybe the mind was stitched together at the seams, not blended. The soul wore the body like a decent suit, but sometimes, the sleeves didn't quite fit. If someone tried to dig around, say, Dumbledore with his damn twinkling gaze, they might just see static. Noise. Or worse, nothing at all.

Fourth, and this one came to him after an unfortunate passage in a book titled Mirror of Memory: Reflections in the Pensieve, there was a chance the interface was subsuming memory. Not just protecting it. Absorbing, converting, flattening all his experiences into its own neat little index. Which meant anyone trying to pry into his head wouldn't get visions or emotions, they would get a system error. A blank field.

Terrifying.

The last theory was more desperate. Maybe his magic, his mind, the interface, whatever it was, all worked because it cheated. Like some ancient failsafe had latched onto the most viable vessel and made it work by force. That would explain the weird way knowledge arrived, like someone slipping scrolls under a locked door.

He threw the quill down. "So either I am firewalled, fragmented, glitched, or possessed by a deeply opinionated magic relic."

Not ideal.

The books didn't give him answers so much as more interesting questions. Half of them contradicted each other anyway. One insisted the soul and the mind were interwoven, another swore they were parallel systems running off different magical currents. A third, written by someone who clearly enjoyed long walks through ego and absinthe, claimed every wizard carried three minds, the conscious, the subconscious, and the ancestral.

Cassian threw that one across the room.

Still, it left a few working rules…

Avoid eye contact with known Legilimens.

Don't sleep near cursed artefacts.

Never attempt to unlock soul-memories unless you've written a will and made peace with reality coming apart.

Solid advice, really.

Cassian tilted his head back and stared at the ceiling. "I gone mad," he said to no one. "Possibly brilliant. Definitely mad."

Still, the pieces fit. If someone like Snape or Dumbledore had tried to break in, and gotten nothing but static, or worse, some kind of rebound, they would have backed off fast. Dumbledore especially. The man had enough secrets in his own skull without getting trapped in someone else's.

He also learned that poking around in someone's mind without permission was very much a magical crime. More so if the someone in question was an heir. Even more if that heir had the kind of bloodline that made Ministry officials twitch when you said their last name aloud in a public loo.

Well. Technically, Cassian was a pureblood heir. His father was the current head of the Most Ancient and Most Noble House of Rosier, and even if Lucian was still top pick for the whole dark-robed legacy package, Cassian had a shot. A bad one. The sort you wouldn't put money on, but still, a shot. If everyone else died in a coordinated broom accident or had an allergic reaction to Muggle-borns, the laws were clear, Cassian counted.

Which meant, under British magical law, his mind was off limits. Ward it, ward it again, and gods help the poor sod who tried to peek without a formal duel and three signed forms.

Not that it comforted him much.

But maybe Snape and Dumbledore hadn't seen anything at all.

Not because he was protected by some cosmic firewall or mystical system with a built-in no-peeking charm. Maybe they just… didn't dare. Yes, that simple.

Cassian sat back in his chair, arms folded, staring at the book like it might confirm his suspicion. If what Bathshedda said was true, and it usually was, then any heir from a proper pure-blood family would've been drilled in Occlumency from the time they could toddle over to a Pensieve.

He hadn't been, of course. His idea of mental discipline was not shouting at the ceiling when books quoted themselves at him. But Snape and Dumbledore didn't know that. As far as they were concerned, Cassian Rosier might've had half a dozen defensive layers tucked behind those green eyes.

Might've trapped them. Might've known they were there. And no Legilimens wanted to get caught rummaging through an heir's thoughts without permission. That sort of thing came with political fallout, and possibly a lawsuit. Or a duel. Or a very stern tea with Uncle Malfoy.

So yeah, maybe they simply hadn't looked.

Cassian chewed on that. Rolled it around in his head like a suspicious wine. It explained why they didn't act strange around him. Why Dumbledore's usual bird-watching gaze had stayed vague and polite. Why Snape, despite every reason to hex him on sight, had mostly stuck to contempt and long pauses.

Maybe they were scared to peek. It was better than alternative...

He cracked the spine of the book in front of him, The Art of Mental Shielding, and flipped to a chapter titled "False Fortresses: When Bluffing is Protection Enough." It was underlined in two colours, one of which was definitely blood.

Cassian drummed his fingers on the desk. He considered testing the theory… asking someone to dig into his head just to see what happened. But that kind of thing didn't come with a refund policy. Best case, someone confirmed his tangle of theories. Worst case, they went snooping, saw too much, and he ended up explaining Bitcoin to the Wizengamot while being held under suspicion of mind-crimes.

Even if it worked, even if everything he read was right, he would still be left with five contradictory theories and no clean proof. It was like asking a cave full of ancient runes if they were friendly. You might get a vision, or a ceiling dropped on your face. Cassian wasn't keen to find out which. Again.

He scratched a line in the margin.

Rule #1: Never trust stillness in people who read minds.

He paused, then added,

Rule #2: Especially if they are wearing robes worth more than your entire inheritance.

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