Disclaimer: I don't own Harry Potter.
Harry was halfway out of his bed before Sirius's hand on his shoulder forced him back down on it. She hadn't flinched, but she dropped her eyes to the ground in shame. "Why?" Harry screamed. "How?"
"Have you ever heard of family secrets?" She asked quietly. He shook his head, eyes darting wildly between her and Dumbledore. She conjured a chair wandlessly and Harry's eyes nearly popped out of his head. She dragged the chair closer to his bed, but not too close.
"All pureblood families are cursed. It is the price they pay for pure blood, or for love, in my parents' case. The curse is kept secret, even from most of the family, and is passed down from the mother. Family curses die out when the male holding the secret marries someone who's secret, or curse, is more powerful than theirs. Usually this is a woman, because the very first family secret was cast on Morgana."
She had barely begun and she knew that was a ton of information. "Family secrets get passed on to the most powerful child in the family line. The child will glow purple to let the parents know they will be the one to hold the secret." Harry's brow furrowed.
"So shouldn't I know one?" He asked.
"Considering both your grandparents were purebloods, although only one of them would have needed to be to pass down a secret to your dad, yes. But your dad died before you turned seven, which is when children find out they're cursed."
"But this doesn't make sense." Harry said, curiosity outweighing his questions about her being a Death Eater. "What about all of the other members of a family? Like don't you have an Uncle? What makes only one strand of the family inherit it?"
Ginny smiled. "Yes. It is quite complicated. However, I told you women's curses typically overpower. The curse follows the typical royal bloodline hierarchy, but it goes through the most powerful member. It can be the eldest, but it isn't always. My mother's family secret, their curse, was much stronger than my father's. I hold the Prewett curse. My mother was the eldest of her father's children who was the eldest of his parents' children. It follows the line of succession and avoids those directly 'in line'."
"So that's why you're a Death Eater? Your family secret?"
"Yes." She responded. "And I have no idea why Dumbledore thinks my disclosing it to you is a good idea."
"He needs to know. You can help him." Dumbledore said softly, but firmly.
"I was born a Death Eater because of who my family is." She said, looking out the window and away from all of them. "I told you it was the Prewett curse but I lied. The Prewetts were forced to adopt my mother to try and stop the curse. Everyone believes that Sirius had three Black cousins. Bellatrix, Andromeda, and Narcissa. But that's not true. Cygnus and Druella had another daughter, their eldest. Molly."
Harry gasped and she smiled slightly, not meaning it. "You're Sirius' cousin! Sort of."
She shot a look at Sirius. "Most of the rest of the family, outside of the child's other parent and siblings, know the curse. So all my family member except for my dad and brothers know about it. That includes Ron. You can't tell him."
"What?" Harry rounded on Dumbledore. "I don't keep anything from Ron. You told me I could tell him everything!"
"Everything except this." Dumbledore said sternly. "Do we need to force you to keep the secret?" Ginny balked slightly, but kept her expression impassive. Harry's eyes darted pleadingly between the three of them before he gave up and nodded.
"Why can't he know? You said siblings don't know the family secret but something doesn't seem right. You said your Mum was sent to the Prewetts to try and stop the curse. To stop it from doing what?" Ginny pursed her lips together and met Dumbledore's eyes. Sirius was watching them curiously as well now. This was the one thing the rest of her family didn't know.
"He's right." Sirius interjected. "There's something I don't know. How? Why?" Ginny raised an eyebrow at the Headmaster. He nodded in silent answer.
"The curse was created as a punishment for the way Morgana used her immense power. So the most powerful in the family line becomes cursed and the previous most powerful in line guides them and helps them. With the Blacks, the curse got to Phineas Nigellus, the old headmaster. It was then passed on to his son Cygnus, and his son Pollux, and his son Cygnus, and his daughter Molly, and then me."
"So you're the most powerful of your siblings?" Harry asked, not unkindly. Ginny smiled.
"I am the seventh daughter and the first female Weasley in generations."
"Seven is the most powerful magical number." Harry repeated. "But, why didn't you get the Weasley curse?"
"I told you. They die out when the person holding it marries someone with a stronger family secret. Mum's, the Black family secret, was stronger."
"Right." Sirius interjected, arms folded. "But that doesn't explain the part I don't know about, and why Harry really can't tell Ron." Ginny sighed.
"It started years ago with Phineas Nigellus' older brother Sirius. Well it started before then, but this was when part of the secret became lost to all of the family except the ones holding the curse. As an infant, that Sirius developed an alarming skin condition. His veins started to turn green. He died of the condition when he was eight. He was an anomaly. Usually, the curse lays dormant and allows the other family members to live long lives, although never as long as the typical wizard. Never over one hundred years old. Why it sped up in him no one knows. But ever since then, those directly in line have kept it from the rest of the family."
"So what? Part of the duty is to save the rest of the family?" Sirius asked. Ginny nodded.
"Only once the mark is defeated can the family be saved." She quoted.
"But this was years ago, way before Voldemort's time. So why are you a Death Eater?" Harry asked, and Ginny smiled at his intelligence.
"Voldemort did not create this mark. It was created eons ago by the very first dark sorceress: Nimue."
"The lady of the lake?" Sirius startled. Ginny smiled.
"Yes. Voldemort simply uses the mark because of its association with power. Lucky for us, because by turning it into the Dark Mark, he made it something that can be destroyed. For years, the chosen keepers of the secret have tried in vain to rid themselves of the mark, some have even killed themselves in the attempt. But the mark could never be defeated because it was only a mark of power. It never personified anything before Voldemort. Mum thought last war that she would be the one to defeat it, but she failed to do so before I was born and now the burden rests with me."
"But you're only thirteen! You can't defeat Voldemort!" Sirius exclaimed, glaring at Dumbledore.
"Not on my own, certainly, but I will play a key role. And once he is gone I will be able to destroy the mark and rid the family of the curse. Besides, since this mark is not one of Voldemort's he can't harm me. I am invincible against him, ironically due to the fact that he stole this mark for his own. I am, however, linked to any magic practiced around this symbol so I get called to all of his meetings. But my power is greater and more ancient than his so he can't touch me."
"But he's the heir of Slytherin." Harry frowned and Ginny was once again amazed at how smart he was.
"Indeed. But he always thought of pureblood customs as silly and archaic, and beneath him. And while they definitely are antiquated and horrible, they do rule this world to some extent. Knowing them and participating in them with the other purebloods is an asset. That was another of Voldemort's grave mistakes: scorning the pureblood world. That's what gives me the advantage."
"Wow." Harry said in response. "Wait. Narcissa. Isn't that…?" His eyed widened comically. "Malfoy is your cousin?!" Ginny grinned.
"Yes. And he and Aunt Narcissa are the only other one who knows everything, besides the four people in this room and my Mum."
"I understand keeping Bellatrix in the dark, but Andy doesn't know?" Sirius asked her. Ginny shook her head.
"She hasn't wanted anything to do with anything Black since she ran away with Ted. You know that. Tonks knows she's my cousin, and I visit them occasionally, when Mum and I can sneak away without suspicion, but that's it." Ginny turned her attention to Dumbledore. "I assume you have a plan?"
Dumbledore bowed his head. "I do. But it's dangerous. Terribly dangerous."
