Author's Note: This story was a bunny based on two things: the Slytherin welcome message stating that there were many Slytherins with 'at least one muggle parent' and Scabior in Deathly Hallows talking about 'Slytherin mudbloods.' As such, I wanted to touch on the idea that it is possible but rare, and...this happened.

Aurora Sinistra sat in the Slytherin Common Room, a glass of elderberry wine in her hand, sitting in one of the carved chairs, considering and waiting for something, before calling out her move to the chessboard in front of her.

Severus Snape shook his head, and whirled the firewhiskey in his own glass, taking a sip before calling out his answering move. "Well, Aurora? What did you see in your stars this time? You only want to play chess when you're planning something." The astronomy teacher was one of his few friends in this blasted castle.

Aurora leaned back, staring at the ceiling, into the depths of the black lake as if it was the sky. "There's something happening, Sev." She murmured quietly. "There's two ways things could go."

Severus dismissed most divination out of hand, especially anything that came from the mouth of Sybil Trelawney, but he had experience enough with Aurora and her stars and more scholarly methods to listen more carefully. "I believe everything has been written for us by Dumbledore."

"Yes." Aurora allowed. "He has great skill as a chessmaster, there's no doubt about that. But he naturally stacks the board against Slytherin. It's his Gryffindor colours and dislike of the Dark Lord coming out." She moved another piece, as if to punctuate her statement.

Severus arched a brow. Aurora would never suggest siding with the Dark Lord, being one of the rare Slytherin muggleborns - which was why Albus had employed her, to shove it in the face of the blood purists. "And you see another route?" He moved his bishop thoughtfully, wondering what the witch had seen.

"We play white." Aurora answered, taking one of his pieces as if to punctuate her statement. "Gryffindors love red...let them play it for once." She clucked her tongue. "It's time for Slytherin to throw off the mantle of villains. Hercules has had his time as hero, it's Odysseus's time now."

"How do you propose we do this?" Severus asked, interest piqued. While he believed his own well of guilt was justly earned and well-deserved, he hated to see what happened to his charges every year, among the suspicious and judgmental students who knew little of what the world was like.

Aurora smirked, knowing she had her friend well and truly hooked, and ordered the chessmen back to where they were. "Pawn to E4." She murmured, watching as it moved. "We attack his plan by moving first."

"If he moves French?" Severus asked, studying the board. "Pawn to E6."

"Then we take him off guard." Aurora replied. "We just need the right pieces. Pawn to D3, instead of D4, where he would expect it."

"He'd move Pawn D5, it's the early game. What pieces are you looking at?"

"Knight D2." Aurora answered, in turn, leaning back. "Well, not the Weasley boy, as he's planning. There's a muggleborn on the list with a very interesting chart."

Severus's eyebrows jumped up. No matter what the stringent purists liked to think, muggleborns in Slytherin were rare, but they did happen. Aurora had been the last, because of the fear that was pushed into them from the word go with warnings of Death Eaters and the ignorant and incorrect assumption that all Death Eaters were Slytherin. "How will you get around the fear? Minerva or Pomona will not shy from warnings of bigotry. Knight F6."

"Knight G to F3." Aurora countered, her smirk deepening. "Because you will be the one to go. He always makes you do at least a few, you just won't be choosing at random this time."

"Me?" Severus repeated, scoffing. "I'm sure that will endear her to Slytherin House." He studied the board, for a moment. "What if he goes Sicilian instead of French?" He reset the board.

Looking at the blank board, Aurora grinned and started with the exact same opening move. "You can actually. Both her sun and moon are in Virgo, it's her mind and her ambition you have to appeal to. Her cunning is mostly focused on defence more than offence, with Mars in Cancer, but if you treat her like you do the older Slytherins and cleverer Claws, she'll respect your knowledge, and you."

"Pawn to C5. Why can't you do this, since you're the one who came up with the plan?" Severus queried.

"Too many eggs in one basket. Besides, I live in Stanwell Moor when I'm not in my tower. I go through Little Whinging to get to Staines." She smirked. "When things go badly, I plan on helping Harry as much as I can before he sends Minerva or Hagrid. If I get both, it'll be suspicious."

Severus could see multiple problems with the plan, but he could also see why it would be utterly unsuspected, especially since he had taken down all of the listening charms for the summer and Aurora had a better than most relationship with the castle. The walls would not inform Albus of their scheming. If they could press the advantage… "Do you really think having us introduce them will make a difference?"

"Absolutely." Aurora said, pressing her advantage with her next move. "The reaction they have to who introduces them to magic always has an effect."

"It didn't for you." Severus replied, taking the most logical move on the board. "Minerva recruited you."

"And I disliked her from the word go." Aurora admitted, shaking her head as she moved a pawn. "The way she looked at our home, at my parents that day, like we were Peckham trash...I wanted nothing to do with her." It was one of the reasons that she had bought her parents a nice little cottage in the Surrey village with her salary and the proceeds from her research.

Severus didn't reply, he knew very well how frosty the relationship between Minerva and Aurora was, nothing needed to be said on that account, even though he doubted that Minerva had intended her attitude that day to be quite so judgmental as Aurora had perceived it. "A muggleborn and Harry Potter, here? The Slytherins may not accept them, unless someone takes them under their wing, someone they'll trust."

"Of course." Aurora agreed. "You have a godson, after all."

Severus was so surprised, he choked on his firewhiskey. " Draco? " He repeated. "You want Draco Malfoy to stand up for Harry Potter and a muggleborn? "

Aurora laughed, shaking her head. "Don't be so shocked. Lucius stood up for you, a poor half-blood. I'm sure Draco understands making connections, and Harry is famous."

"And the muggleborn?" Severus asked, wrinkling his nose. "Lucius has done a number on that front, Narcissa doesn't curb his tongue in front of the boy."

"Advise him." Aurora suggested, easily. "I know Lucius has you preparing the boy for school; add social niceties to the list. We both know he respects you. He wants to make Lucius proud, yes...but you've been trying to mitigate the effect on him as much as possible all along."

Severus glared at her, but didn't argue. "This summer will be very interesting."

"It will, indeed." Aurora agreed. "Checkmate." Her braids swung as she knocked over the red king with an air of pride.