A/N: This is my first story, please be kind. I welcome constructive criticism but please no flames. As as always, I do not own Twilight, Supernatural, nor do I own Harry Potter. This will be a crossover, though we will not enter the Twilight world until later on. I am not a huge fan of many of the characters in Twilight, but I will try not to openly bash them. I am primarily using Twilight for its general premise. The ideas of vampires going against their nature and protective shapeshifters is intriguing. Supernatural will not be big in this story, but there will be ideas and maybe a small amount of interaction of the characters from the show.

Prologue

Multi-coloured sparks shot through the air. It was over- it was finally over. The months of starvation, being in and out of a semi hypothermic state, and wearing Tom Riddle's bloody horcrux was finally at an end. Most of his Death Eaters and other allies were either captured or dead; the few that were unaccounted for would later be hunted down and brought before the Wizengamot for war crimes. Justice will prevail over Britain once again though its saviour will not be there to witness it.

Revelations, Old and New

Harriet Dahlia Potter sat in the headmaster's office as she waited for Kreacher to bring up some sandwiches. She felt a unique sense of relief, sorrow, euphoric joy, and crushing guilt. Remus and Tonks were dead, Fred was dead, little Colin Creevey was dead, as were so many others that had fought with her- fought for her. Many others weren't guaranteed to live through the night, and if they did, some in their numbers would be labeled as "dark" due to the creature they now had inside of them. War changes everyone, but Harriet hoped that something good would rise from the ashes of this war. "Dear girl, you did it! I apologize for the way in which I guided you, I thought it was in the best interest for the greater good. Can you forgive an old man and his foolishness?" the portrait of Albus Dumbledore broke the silence. Harriet glanced over her shoulder and gave him a weary half smile.

"I can't forgive you now professor, but one day I will. If you were less fond of riddles and secrets, maybe the casualties would not have been as great. But I cannot begrudge you your faults; after all, you were only human." Harriet turned away from his portrait and pondered that last thought. Only human. Yes, Dumbledore was a great man, a great wizard, but he was only human. He was still fallible. That fact had taken Harriet a lot longer to accept than Hermione. Hermione had raised those questions one bleak night in the tent after Ron left. It took Harriet until her "dying" at Riddle's wand to understand what Hermione had meant when she criticized Dumbledore. But it was Harriet's "death" when she realized that, and so much more. It was at that threshold between life and death when she first met it. Its name being Death. And oh, was Death dying to speak to her.

Death first appeared as a young woman with silver hair, black eyes, and in a dress that was reminiscent of a funeral shroud. Then, as soon as it appeared like that it changed, becoming an old, skeletal man, in a black suit with slicked back black hair. It kept changing as it spoke to her. "My child," Death started, "You have come so far since I first beheld you. You know what you are, now you will find out what you truly are and will become. I am your friend and loyal companion, Death."

"Wait, what? The story of the Three Brothers is real? There is a Master of Death?" Harriet incredulously exclaimed. She figured the Hallows were real enough but thought the whole bit about Death was a load of tosh. It seemed more likely that the wizards in the story were exceptionally powerful and created the legendary items.

Death smirked at her. "The moniker, Master of Death, is a term wizards have used through the centuries to try to claim power over that which they do not understand. It would be as if a gnat came to you saying they were your master. No, you are so much more and yet so very less than what that name implies. What do you know of your heritage?" Death started to change shapes again, morphing from the old man to a little boy who could have been Harriet's twin when she was younger, until it settled again on a young-looking man with her bottle green eyes, long raven hair pulled back in a thong, and ancient looking robes.

Harriet looked at Death quizzically. "All I know is that my father was a pureblood from the Potter line and my mother was supposedly a muggleborn. Although, last year, that was thrown into question when I had an encounter with a vampire."

Death looked on, eyes gleaming, "Oh, do tell. I am most intrigued what this vampire had to say."

She sighed as she threaded her fingers through her unruly hair, "Well, I think he had it wrong, it made no sense." Harriet muttered softly. "I was at this Christmas party at school when I met him, I had never seen him before. He took one look at me and, if he wasn't so pale already, I swear he went white with fright. He proceeded to bow to me, calling me Your Highness. Everyone else thought it was a joke so they laughed and ignored it. When he calmed down, he told me that all the vampires thought that my kind was extinct. I asked him what he meant and he proceeded to tell me that I was a Royal, part of the line of the first vampires, and that he knew because of my eyes. The thing is, my eyes are the same as my mother's. I thought it was an elaborate prank of some sort. So I did some research and found put there was a line that was considered vampire royalty and they supposedly went extinct. But if that is the case, how come my mum never became one?"

Death looked proud, "I never thought Sanguini remembered that far back. Sanguini was correct in what he told you. Your eyes do show your lineage, and when you reach the age of eighteen you will start into your inheritance. You will reach full maturity at the age of 24, then will you be a full Royal."

Harriet with brow furrowed asked, "And what about my mother, does that mean she was a Royal too? What is a Royal anyway? The books were never clear on that."

"Your mother never could have become a Royal. She was close to it but her magical core was not strong enough." Death sighed, "This will sound a bit crass, mostly because of what you are fighting for, but it had to do with her parentage. Her magical ability came from her mother's side, her father's side never had magic. For a Royal to come into being they must have two magical parents. As for what a Royal is, they are nothing like the types of vampires known today. They are more like dhampirs; they are daywalkers, they can subsist on both regular food and blood, they are exceedingly fast and strong, and they are powerful sorcerers. They can make vampires like your friend Sanguini. By the combination of a Royals venom and blood, a vampire can be made. Royals can have children, and those children will be Royals as well, so long as the other parent is magical." Death looked at Harriet before continuing, "As for what Royals really are, they are my children, my balance. You are thus my child, a greater treasure than any 'Master' could be, but still less than I. The Hallows were originally mine, they were how I created the first Royal, and they were stolen from me by your other ancestors, the Perevells."

Harriet was shocked. She figured the Perevells were her ancestors, the cloak was a family heirloom after all. The shock more came from the fact that Sanguini was correct, that her mother was not a true muggleborn. "Wait, if mum wasn't a true muggleborn, if she was a descendant of these Royals, who were they and how come we know nothing about them now?"

"You know of them, one of them built the castle you call home, Salazar Slytherin." Harriet involuntarily shivered at that, but before she could ask anything more Death started again. "Now, I know that little knut of information brings about many more questions. Questions you will eventually get answers to. But our time here is running short so pay attention. You are the true Heir of Slytherin. After you kill Tom Riddle, yes you must kill him, go to the headmaster's office and Floo to Gringotts for an inheritance test. I know they will not be pleased to see you due to that spectacular theft but stand your ground and get that test done. From there, go to the Slytherin vault and take out the black trunk, it has all the information you need to start your journey as a Royal. Remember, do not tell anyone what you are until you have reached full maturity. There must still be a few that remember Royals, what they mean in the world, and how to destroy them. You will be vulnerable until then. I will see you again my child, good luck." With that, Death touched her forehead and she woke up in the clearing that Voldemort had just struck her down in.

Harriet was startled out of the memory being replayed in her head by a bullfrog -like croak. "Mistress, Kreacher has Mistress's food as requested. Shall Mistress care for a butterbeer or pumpkin juice?"

Harriet shook her head at the ornery elf. He only just started to accept her as his Mistress, and for all his past transgressions she was starting to care for him. "Thanks Kreacher, I'll take a Butterbeer if it's warm."

Kreacher snapped his gnarled fingers and a warm mug appeared on the desk in front of her before saying, "Kreacher lives to serve the Noble House of Black," then disappearing once more. Harriet shook her head in exasperation before digging into the sandwiches and butterbeer before her. She hoped that Ron and Hermione at least were able to get something from the elves in the kitchens, feeling slightly guilty for disappearing on them once more. That guilt was assuaged, however, when she remembered Death's instructions. It would be of no use to being delayed any longer and she understood that her looking as battle-worn and fatigued as she felt may benefit her in this situation. If she told her two best friends her new mission, well, they'd talk her into at least getting some rest before she moved. No, she knew that Death's instructions must be followed to the letter, the only deviation being some food before she keeled over from hunger and exhaustion.

With a last swig of butterbeer and a fortifying breath, Harriet grabbed a handful of the green powder next to the fireplace and stated, "Gringotts Bank!" before stepping through.