Cassian scratched his chin, looking at the gathered professors. "Right, so everyone here is placing something with their subjects. Should I just drop a History textbook and ask the intruder to memorise it?"
McGonagall gave him a sharp look, but Dumbledore was already nodding, with that mild, cryptic thing he called a smile.
"Only if the penalty for failure is being forced to cite footnotes under pressure," he said.
Cassian clicked his tongue. "Oof. That is worse than fire."
Dumbledore chuckled. "I trust your expertise, Professor Rosier. But remember, we are not looking to injure. These protections should delay, dissuade, confuse. Not maim."
Cassian raised a brow. "Cognitive bruises, not broken bones. Plausible deniability, got it."
Snape didn't bother looking up. "Perhaps if History offered something useful, you would have more to contribute."
Cassian turned, expression perfectly bland. "Oh, we do. Your blood pressure spikes every time I open my mouth. That is historically consistent."
McGonagall sighed through her nose.
Dumbledore raised a hand before anyone could start throwing hexes. He then turned to the room, hands clasped. "We are, all of us, the first line. This item, this matter... must be kept secure through the year. Quietly. Your contributions will be layered and distinct, difficult, but not impossible."
Cassian got up and lazily waved, "Got it. Will think of something fitting."
As he turned to leave, Dumbledore's voice caught him.
"Professor Rosier, this matter is too sensitive. I would ask that you not share it with Professor Babbling."
Cassian stopped mid-step, turning slowly, brow already rising. "Right. Well. That is a bit late, isn't it?"
Dumbledore tilted his head. "I should have warned you earlier, and I apologise for that. But still, I ask—"
"You will have to do better than ask, Headmaster." Cassian didn't raise his voice but it was clear he was irritated. "You see, I don't hide things from Bathsheda. Not even the sensitive sort. Makes partnerships easier. Bit less betrayal, bit more actual conversation."
McGonagall looked like she was deciding whether to interrupt or combust.
Dumbledore remained still. "I understand that, and I commend it. Truly. But I still ask that you don't."
Cassian stared at him. "You commend it," he said slowly, as if tasting the word and finding it faintly ridiculous. "You commend honesty, but want secrecy. That is rich."
Snape shifted near the shelf, like he had something to say but didn't want to be accused of agreeing with Cassian.
"Or," Cassian added, "you are welcome to Obliviate me. Cleaner that way. Saves us the awkward silences."
Dumbledore paused, studying him for a few seconds, then said, "You must see, Professor Rosier, secrets protect more than people. They preserve perception."
Cassian shrugged. "Sorry, I am not comfortable with what you are asking. Especially not when it involves someone who knows where I sleep and once cursed an entire forest for calling her handwriting sloppy."
Seeing his stubborn face, Cassian sighed, "Fine, I will throw you a bone," he said. "You have to tell her that. Next time you see her. You tell her. That I kept something from her because you asked. Make it clear it wasn't my idea. Because I won't lie to her, but I will shut up, if you want that badly enough."
"Your loyalty does you credit," Dumbledore said. "But—"
"Sorry, Headmaster," Cassian said. "I am trying not to lose the only person in this castle who doesn't think I am either expendable or a court jester."
Snape's mouth curled, faintly. "Debatable."
Cassian didn't even glance his way. "Feel free to add me to the list of people who don't care about your opinions, Severus. If you find a space, that is."
Dumbledore raised a hand. "Very well. I will speak with her."
Cassian gave a nod. "Good. She is smarter than all of us anyway. Might've figured it out before I said anything."
"Then it is settled."
"For now." He turned again, hand briefly brushing the doorframe. "And Headmaster?"
"If whatever you are hiding ends with anyone bleeding in the hallways, I am not sticking around to say 'told you so.'"
Dumbledore gave a quiet hum. "Noted."
Next morning, over toast and a cup of whatever passed for orange juice in Hogwarts (Cassian had his suspicions), Cassian took another spoonful of yoghurt, freshly made by the house-elves, thank you very much. Bathsheda slid into the bench beside him and passed the butter without asking.
"I know," she said, casual. "Whatever it is Dumbledore told you not to share. It is fine."
Cassian looked up, catching something new in her face.
So Dumbledore had mentioned the whole bit... Cassian refusing to keep secrets, demanding Dumbledore say it himself. That stubborn streak wasn't exactly private knowledge.
The look she gave him now... fondness, sure. But also something else. He was getting lucky. Damn pretty soon at that.
After breakfast, Cassian made his way to first class of the year, Third-year Gryffindors and Ravenclaws. Which meant the Twins. Lee Jordan. Kenneth Towler.
Cassian stepped into the classroom with the kind of caution usually reserved for cursed tombs. The room was already half-full, students milling, chatting. Cassian dropped his bag beside the desk, took the chalk.
"War Runes and the Curse of Bellodrix the Unwashed."
"Is that a real name?"
Cassian spun the chalk back into its tray. "Absolutely. Though history's been kind enough to shave off the 'Unwashed' in most formal records, more than she ever did in her life, apparently. I prefer honesty."
The Weasley twins slid into their seats like a matched pair of smug cats, muttering apologies for being late. Lee Jordan behind them, already passing a folded note to Angelina. Cassian caught it midair with two fingers and set it on his desk without looking at it.
"Save it for after class. Or frame it if it is poetic."
George leaned forward. "What if it is rude?"
"Then definitely frame it. Hogwarts needs more creativity on the walls."
They laughed. It usually came before interest. And history, contrary to popular belief, was rarely boring if told right. Especially the parts with curses and lunatics.
Cassian leaned against the desk. "Right, war runes. Now, before we dive in, quick poll. How many of you know what a rune actually does?"
A few hesitant hands. Some confident ones.
He checked the hands and nodded. "Right. Rune class is elective from third year onward. Some of you are probably taking it already. The rest went with easier options... less homework, simpler exams, and maybe a few less exploding eyebrows. No shame, just lower ambitions."
Angelina raised her brow. Cassian pointed lazily toward her scroll. "Not judging. Just observing."
He pushed off the desk and started pacing in front of the blackboard.
"Now, war runes." He gestured broadly. "Not the polite sort. Not the kind you etch on family crests or waggle at doors for security. These are the old ones. Pre-Merlin. Pre-language in some cases. The kind you would carve into bone before storming someone's village."
Kenneth frowned. "Into bone? Like a chicken bone?"
Cassian nodded. "Bone holds magic better than bark. Especially human. Don't worry, we are not doing samples today."
Fred whispered something to George. George grinned.
Cassian didn't look. "And no, Weasley, you may not volunteer your brother's tibia. Save the jokes for someone who hasn't taught twins before."
Fred raised both hands in mock surrender.
"So. Bellodrix. Why do we care?" He waved his wand. The writing on the board reshaped into a crude stick-figure riding what might've been a bear. "Because Bellodrix was mad. Not the fun sort. Not the 'danced with fairies and declared herself Queen of the Creek' sort. She believed her magic could make armies invisible. And it sort of did. Once. For ten minutes. Then it made their teeth explode."
That earned a few snorts. Roger Davies looked up from whatever diagram he was mentally sketching.
"She worked with war runes the way you might juggle basilisk eggs. Sometimes brilliant. Sometimes fatal. Today we are looking at one of her surviving designs."
He flicked his wand again. A rune sketched itself onto the board in harsh, jagged strokes. The symbol had teeth... angular, so sharp, it could gouge the wood behind the chalk.
Lee Jordan leaned forward. "That doesn't look safe."
"Good eye." Cassian pointed at the top arc. "This loop? She thought it would bend light around a shield wall. Did. Briefly. Until it caught fire. This line here... meant to blind enemies. But when drawn upside down, it gives everyone within ten feet migraines and spontaneous nosebleeds."
"Now." He clapped. "We are not learning how to inscribe. Don't even pretend to. This one is on the banned list unless you are certified and prepared to lose an eyebrow."
"Are you certified?" Angelina asked, a challenge in her tone.
He chuckled. "Course not. And that is not even a real rune. If runes worked just by drawing them, every idiot with a wand and a crayon could call themselves a war mage."
A few students blinked. Alicia stopped mid-scroll-scribble. Cassian stepped away from the board, tapping it with his wand. The chalk lines fizzled out in a soft puff.
"Runes only mean something when you charge them," he said. "Magic, intent, context. Scribble that in your notes, Davies. Intent matters. Especially with runes. Otherwise, you are just decorating bones."
Lee raised a cautious hand. "So... how did Bellodrix charge hers? With spells?"
Cassian tilted his head. "No. Blood. Mostly her own. Sometimes others'. War was generous like that."
That earned a pause. Even the twins looked less cheeky now.
"She believed the rune had to be fed," he went on, stepping between rows. "Not metaphorically. She would cut her palm, let it drip onto the bone, then chant something that probably sounded like a seagull choking on a pipe. Sometimes it worked. Sometimes it didn't. Once she lost three fingers and her voice for a week. Still called it a win."
Cassian raised a brow. "Historically, the line between madness and genius is just whichever one writes the records."
Angelina raised her hand slowly. "So... why are we learning about her?"
He glanced over, impressed. Good question."Because she made history messy. And gistory is mostly made by lunatics with enough magic and not enough supervision."
A few laughed. Fred scribbled something in George's notebook, and George grinned wide.
Merlin had legends. Binns has naps. You... Well, not all of us contribute something.