Harry Potter and the Sorceress of the Stars

Professor Snape brought Potter, Weasley and Oleandra to his office. He looked into Oleandra's eyes, a frown on his face, but he suddenly turned away after an instant, a pained look flashing on his face briefly.

"I expect better from students of my House, Miss Greengrass," he said, shaking his head slowly. "This dunderhead and his faithful sidekick I can understand, but this is unacceptable."

He pulled out a newspaper, tapping it. The headline read: FLYING FORD ANGLIA MYSTIFIES MUGGLES.

"Now, Miss Greengrass, where are your sister and your little friend? They didn't arrive on the school train either."

"There must have been a mix-up," Oleandra said innocently. "I assure you I did not travel with these gentlemen. The barrier at King's Cross station was sealed, so I Apparated here, but got separated from my companions."

"I find that hard to believe," said Professor Snape darkly. "Hogwarts is warded against Apparition. If your goal is to get out of punishment with lies, then I suggest you start with a more believable one."

Wordlessly, she handed him the letter she had just received from the Ministry.

Now that she had proved her innocence, Snape had no excuse to hold back on administering punishment to Potter and Weasley, since his student wasn't involved. 

"You were seen," said Professor Snape to the other two. "Weasley, I don't think I need to point out the irony. Your father works at the Misuse of Muggle Artefacts Office, does he not? His very own son…"

"You've also considerably damaged a very valuable Whomping Willow," said Professor Snape, as he continued enumerating their misdeeds.

"About that," said Oleandra timidly. "I appeared in the tree; they saved me by ramming their car into it."

Potter and Weasley looked gratefully at her, but Professor Snape didn't seem convinced.

"Snape couldn't really be able to read minds, could he?" wondered Harry.

"All of this is grounds for expulsion. Most unfortunately, you are not in my House and the decision to expel you does not rest with me. I shall go and fetch the people who do have that happy power. You will wait here," Professor Snape said gleefully. Or at least, as gleefully as he could outwardly appear.

"Thanks for standing up for us," said Potter. 

"It was nothing," said Oleandra tiredly. "You did save me, after all."

Weasley tried his best not to look guilty. Saving her had been a complete accident.

After an uneasy ten-minute wait, Professor Snape returned with Professor McGonagall and Dumbledore, with Tracey and Daphne in tow.

"Severus, while Minerva deals with her students, might I borrow these three?"

Professor Snape gave the go-ahead, and they went into the neighbouring room.

"How did you penetrate our wards, Miss Greengrass?" Dumbledore began.

"You know how," answered Oleandra noncommittally. Why was he asking obvious questions? "Rune magic."

Dumbledore squinted at the three of them over his crescent moon glasses. He still couldn't read Oleandra's thoughts, but he was beginning to receive static when reading Tracey and Daphne's minds. What on earth was she doing to them?

The reason for this is that Oleandra's special brand of rune magic engraved magical symbols into the very soul. Magic interferes with magic, and as Daphne and Tracey mastered more and more runes, so would their very minds become incompatible with magic that dealt with the brain and the soul! This was a qualitative change whose main purpose was to improve control over star magic, and didn't have any negative effects like a Horcrux that weakened the soul by dividing it.

Nevertheless, he had still got the gist of what they had been planning, and as far as he knew the barrier sealing itself had nothing to do with them. Even so, he was uneasy. After all, he had known from the start that Tom Riddle was a bad egg, since he could read his mind in the boy's early years before he had mastered Occlumency. Dumbledore had hoped he would have changed, but he had never trusted him, even refusing him a post as Defense Against the Dark Arts teacher back when he was still handsome and beloved by all. Incidentally, that was why the post was cursed; no single person could teach the class for more than a year.

Dumbledore reluctantly handed the trio back to Professor Snape, who assigned them detention. It was getting late, so he sent them back to the Slytherin common room, where the three were greeted with a storm of applause and hooting.

"Well done!" said Draco, laughing. "You should have seen the face on that Weasley girl! You should tell me next time you pull something like that again, I'll join you! I'm always ready to stick it to those blood traitors."

Daphne blushed, and Pansy stared daggers at her. Clearly, she was the jealous type.

Tracey Davis looked very pleased. She was the kind of girl everyone unconsciously forgot about, so she was enjoying the attention.

Oleandra, meanwhile, was talking and laughing with the various people who came to congratulate her. She was scouting for potential candidates for her new club. So far, as far as competent people her age went, there was Draco Malfoy, and Mafalda Prewett. She had learned of Mafalda last Christmas, when the adults had had a bit too much alcohol in their systems. She was in Slytherin just like her, but she was actually muggle-born! She was related to the Prewett family from her Squib father, who was Molly Weasley's second cousin. Oleandra's head had spun upon trying to make sense of her relationship to Mafalda, but as far as she could tell, they were third cousins. 

It was a hard choice to make. Mafalda was incredibly gifted, but she was muggle-born. Draco wouldn't want to join a club with her in it, but he was fabulously wealthy. In the end, Draco's wealth had very little impact on Oleandra's decision. Having someone so despised in her club would do more harm than good, so she decided against having her join.

Later that night, Oleandra had her owl Pyg carry a letter to her parents. She was well aware of the little tricks nobles used to get out of trouble, so she wanted to contest the strike the Ministry had put on her record. She would have an inspector use Prior Incantato to prove she hadn't used Apparition. The spell would reveal she hadn't used the spell she was accused of using. Her rune magic didn't need a wand, so her appeal was basically foolproof. She had never Apparated, after all!