Snape loved libraries.
He loved the dingy shelf of books in the back room that counted as a library in the Snape household. He loved the days when Lily had dragged him off to the local Muggle library to beat the summer heat. But most of all he loved the Hogwarts library.
It was quiet. It was full of books. And the Marauders had a near universal ban against gathering together after a series of mistaken pranks that had resulted in an original copy of Aristotle's Menagerie been transfigured into a vase and broken.
Here, he and Lily could meet in peace. Study their respective passions in the companionable silence of the studious. Quietly debate the relative merits of copper vs gold ladles and where charms ended and jinxes began until Madame Pince shushed them.
But today, his studies took him to a wing of the library he rarely travelled: genealogies and pureblood history. There were books here that would only open for certain bloodlines and curse anyone else who tried to touch them. There were diaries, journals, and memoires from long lost bloodlines (since the Hogwarts library had legal rights to any unclaimed books and ephemera in vaults and wills). It was not a place he wanted to be seen studying in. So when Lily entered the library to return some books and glanced around for her usual study partner, Severus duck further into the stacks to avoid her.
Genealogy and history were dull subjects on a good day, but Snape was on a quest like a niffler digging for gold. He was here to save Lily after all. Narcissa might appear to be helping out of the goodness of her heart, but he didn't trust that any of the Blacks were born with such organs of compassion. No, what he needed was leverage on her. The threat of something.
Had she been anything less than the youngest daughter of one of the oldest and most powerful houses, Severus would have relied on his reputation and a few whispered warning of how strange potions sometimes found their way into familiar drinks. But he couldn't threaten one of the Sacred 28, so he turned to the books to find some clue.
Around the fourth hour of dedicated research, Severus paused and went to the history section.
After the fifth hour, his table was littered with scrolls and intricate family trees.
After the seventh hour, Severus rose to his feet, cracked his back, and stretched his cramped and aching fingers. With a small, grim smile, he vanished the collection of notes and diagrams and sent the books back to their shelves.
~ A Lily Before the Storm ~
Narcissa was holding court disguised as a study session in the Slytherin common room. They were not old enough to claim the prime chairs by the fire, but the strength of the fourth year girls' families had ensured they had a dedicated table for their purposes.
As Severus approached, gossip ceased and the table grew quiet. Narcissa looked up and raised an eyebrow. It was clear that his presence wasn't welcome, but equally clear that she would hear him out. It was a small token, but one that filled Snape with a vicious pleasure.
"Lady Black," He gave a short, stiff bow as protocol dictated, "please forgive this interruption of your time and conversation. Might I have a word with you?"
Intrigued, Narcissa nodded and the four other girls scattered back to their dorm or to other corners of the common room. The interaction had already gathered interest from the other members. No doubt gossip was already being whispered as to what possible reason Snape had to interact with a Black sister. Conscious of prying ears, Severus erected a series of privacy spells that were effective enough to block out the causal listener, but not so strong as to arouse suspicion. Many such bubbles of silence existed in the dungeon.
"May I be so bold as to put Madame Goshawk's skills to the test," Narcissa smiled. Madame Goshawk was the resident divination teacher and a dear favorite of the female population of Hogwarts. "I believe you are here about a certain, now mutual, acquaintance?"
"On the contrary," Severus met her smile with a thin lipped one of his own, "I wish to speak of something much closer to your heart, Lady Black: your family."
"Oh?" Narcissa cocked her head and blinked at him guilelessly, "What has Bella done now?"
"Not just Bella, but rather all three of you black sisters." Severus leaned forward and fought to keep his expression pleasant as if they were discussing intricacies of homework, "I have been doing some research today and have uncovered some interesting facts about the Blacks. Did you know that you have been one of the oldest and most powerful families not just in the past century but as far back as records go? Or once every century, three sisters are born to the main family?"
Narcissa's face had gone carefully blank, but her voice remained light and teasing. "How interesting, Mr. Snape, to have you take such an interest in our history. Were you perhaps looking for some connection to the Prince line? I believe Aquilla Black married a Septimus Prince in 1813. Wouldn't that make us cousins of a sort?"
Every pureblood was every other pureblood's cousin by some degree. Snape refused to be dragged into another line of discussion.
"What is interesting is these sister's marriages," He continued after a moment, "More specifically, the contrariness of their tastes. For instance in the War of the Crossed Thornes in the early 4th century, Sagitta Black ended up married to Odel Lewthwaith while Ara Black married Randolf Carrow both of who were the aggressors of the war. Of course, the Lewthwaith's were wiped out to the last man and child and their lands, spells and items stolen. But Ara's second son Corvus was granted the title of Lord Black plus a fraction of the captured land and goods. Thus the Black family survived."
Narcissa had gone completely still and her eyes had become hooded. There had always been some unkind talk comparing the girl's blond hair to her dark haired sister. But at this moment, the family resemblance between her and Bellatrix had never been clearer. Severus knew he had found a weak point in the Black family armor.
"Perhaps a more recent history might interest you. In 1543, when the Dark Lady Malaury declared herself in opposition to the encroaching tides of both the Arabian wizards and the Italian Oligarchy and the entire world seemed to be coming to blows, didn't Norma Black run to her side and become her lover while Corona stayed and-"
"Mr. Snape, forgive me for interrupting your lovely recounting of my family's history, but these are stories I already know and fail to understand why you find them so interesting. I hate to put words in your mouth, but you seem to be accusing us of either making advantageous marriages or following our hearts- neither of which seem worthy of mention. Our history of purebloods in England are riddled with such daring tales of love and loss. There may even come a time when your great- great grandchildren are discussing your resurrection of the Prince line and subsequent marriage in equally starry eyed terms. I don't-"
"Then let me be clearer." Severus leaned backwards and tapped his finger on the table to illustrate his points, "Your family plays the odds. Whenever there is a conflict- one sister will marry into one side, another in the opposite ensuring that the Black line will continue no matter what outcome. "
Narcissa hesitated a little too long before shrugging prettily, "Perhaps. I've never considered it that way, but I suppose if you look at our history with a particular bias, you can see whatever it is you want to find. This has been interesting, Mr. Snape, but I have an essay I need to finish before bed."
"Of course," Severus half rose but then a thought seemed to strike him, "I wonder if Lord Malfoy would be interested in such a biased take on your history. It would be quite a shock to suddenly have you throw yourself at some Dumbledore faction pureblood. Considering how interested Bella is in certain parts of our society." He delighted in the quick wince that flashed across her face as he threw her words back at her.
"Sit down, Mr. Snape. I find I have some further questions about my essay." Her voice was low as she pulled a paper towards him and pretended to show him what was written. He was astounded to see a neat list of questions all centered around Lily. Who were her friends. What her thoughts of magic were. Where was she most gifted, least gifted. How close was she to her family.
"Currently, I am engaged in quite a bit of research on a subject dear to us both. It would serve both our interests to see this project come to completion, but I find myself hesitating on my lack of knowledge. Perhaps you could do some research for me? It would be a pity, of course, should my findings come back negative, just as it would be a pity for you to waste Lord Malfoy's time with history lessons." Narcissa glanced up at him and he nodded slightly.
A draw. He had found his leverage over her, but she still had leverage over him. If he told Lucius about his findings, she would deny Lily Tutella Hebes. Furthermore, they both knew what was at stake. It was a balance that Severus could live with for the moment.
"It would be my pleasure to help you in anything you require, Lady Black," He took the sheet from her and folded it away into his pocket. "It is my dearest hope that your extracurricular research comes to fruition."
"And mine," Narcissa agreed frankly. She favored him with a brilliant smile and, for the first time, Severus felt that he was seeing the true Narcissa, "I have placed many great hopes on this project."
"Then I won't delay." Severus rose and bowed once more before heading back to his rooms. Lily was, once again, safe. Though he would need to see why Narcissa was so interested.
A/N: this was, perhaps, the most fun chapter to write yet. I love coming up with random parts of fake history.