Harriet Lilith Potter was born on 31 July, 1920 to James Charlus Potter (born 27 March, 1900) and Lilith Rosalie Potter née Evans (born 30 January, 1900). James was a rich pureblood wizard, an officer in the British Magical Army in the war against the Dark Lord Grindelwald, which was the magical side of the Great War. His wife was a muggleborn witch who ended up fitting perfectly into pureblood society and the fight against evil, an inspiration to many pureblood ladies. When Harriet was born, the Potter family immediately went into hiding, as Grindelwald had an apprentice, a new Dark Lord who went by the name of Lord Voldemort, and soon after the end of the war and Grindelwald's subsequent defeat by Albus Dumbledore, a seer prophesied the defeat of Lord Voldemort at the hands of young Harriet Potter.

On 31 October, 1921, when Harriet was a year and three months old, the Potters were betrayed by Peter Pettigrew, and Voldemort attacked. Lily and James were killed, and Voldemort was temporarily vanquished, having been unable to kill Harriet. The child was sent to live with muggle relatives, Petunia and Vernon Dursley and their son Dudley. The Dursley family despised her, and treated her worse than a slave, beating her daily and forcing her to do all the cooking and cleaning. When she was eleven, she discovered magic was real when she received her Hogwarts letter and starting attending the school. The first year, she killed Quirinus Quirrell, who was hosting Voldemort's spirit, when he attempted to steal the Philosopher's Stone in order to give Voldemort a new body.

Her second year, a piece of sixteen year old Voldemort's soul possessed Ginevra Weasley, a first year and the younger sister of Ronald Weasley, one of Harriet's best friends. It made her do his bidding, including release a one hundred and twenty foot long basilisk, which Harriet slew with the Sword of Gryffindor at the end of the year, when Ginevra was taken into the chamber of secrets, where the basilisk resided. She also killed the piece of Voldemort's soul, and was bit by the basilisk, although she was saved by Dumbledore's phoenix, Fawkes. Her third year, Sirius Black escaped from Azkaban Prison. Sirius was her godfather, and he was supposedly the one to betray the Potters to Voldemort. She ended up discovering that this was a lie, and Peter Pettigrew was actually the betrayer. Peter was also Ronald's pet rat, Scabbers. She and her other best friend, Hermione Granger, rescued a hippogriff condemned to death the night of this discovery, and used him (Buckbeak was his name) to rescue Sirius, who had been captured and sentenced to the Dementor's Kiss, with no opportunity to reveal the truth.

Her fourth year, there was a Death Eater attack at the Quidditch World Cup, and Harriet was almost blamed for the casting of the Dark Mark. During the year, she was illegally entered into the Triwizard Tournament as the fourth champion and then forced to compete. She almost died several times, and during the Third Task, she and Cedric Diggory, the other Hogwarts champion, were portkeyed to a graveyard in Little Hangleton, where Voldemort and Pettigrew awaited them. Cedric was murdered immediately, but Harriet (or more specifically, her blood) was used in a dark ritual to give Voldemort a body. They dueled, and Harriet barely escaped, bringing Cedric's body back to Hogwarts with her.

Her fifth year was terrible. During the summer, she attacked by dementors, causing her to cast the patronus charm, which meant she was expelled for use of underage magic, and then she was unexpelled because it was a life-threatening situation. During the school year, she was tortured daily by her Defense Against the Dark Arts teacher, Madam Umbridge by use of a Blood Quill, or Black Quill. She ended up forming a secret, banned, defense club called the Defense Association and teaching over thirty other kids. At the end of the year, she and several of the DA members flew by thestral to the Ministry of Magic, where they headed to the Prophecy Hall in the Department of Ministries in order to rescue Sirius, only to find that it was all a ruse and Sirius was fine. They battled several Death Eaters, and then the Order of the Phoenix arrived and so did Dumbledore and Voldemort. Sirius ended up dying, she cast the torture curse on Bellatrix Lestrange, and then she battled Voldemort.

Her sixth year, she had private lessons with Dumbledore, and at the end of the year, he was murdered by the potions professor, Severus Snape, who was apparently a Death Eater. She and Hermione and Ron went on the run for her seventh year, hunting horcruxes, and then, on 2 May, 1938, the Final Battle Began. Both the Light and Dark sides suffered many casualties, but it was soon over, Voldemort having been vanquished by Harriet, who died during the battle, causing the piece of Voldemort's soul in her head to die permanently, and she to come back to life. After the war with Voldemort, Harriet didn't know what to do. So, when World War II started on 1 September, 1939, she joined the British Magical Army and fought in the war, heading the Dragon Division. But when the war ended on 2 September 1945, Harriet had nothing. Hermione and Ronald had both died during the war, as had most of the rest of her friends. Even the Dursley's were gone. So, she packed her things, transferring all her money into American muggle money, and stepped through the Veil of Death in the Department of Mysteries.

Harriet passed out as soon as she was completely engulfed by the Veil. When she woke, she was in an city she found both familiar and strange. It was New York City, she believed, but it had changed quite a bit from the city she knew. Casting a quick tempus, with the intent to reveal the date as well as the time, her already pale face paled further. It was 11:32 AM on 4 May, 2012! She'd traveled forward in time by 67 years! Ducking into an alleyway, she attempted to apparate to the Leaky Cauldron. She found a muggle bookstore instead. St. Mungos was a department store, Hogwarts was still there, with all the wards and everything, but it was completely bare of any life, there was no basilisk, no house elves, no people, nothing.

Harriet spent the next month apparating around the world, looking for any familiar magical places or people. Finally, she concluded that she was in an entirely different world, and she called Death to her side. After the Final Battle, Harriet had discovered that she didn't really age, and her wounds, even ones that should have killed her, healed extraordinarily fast. Then she discovered that the Elder Wand and the Resurrection Stone always returned to her, despite her attempts to destroy both of them. She would have destroyed the Invisibility Cloak as well, but it was a family heirloom, one of the only things she had of her father, and it didn't do any harm.

So, after she had made these discoveries, Death had appeared to her, told her that since she was so pure as to never want immortality, and in fact she had united the three Deathly Hallows to stop a madman in his quest for that very thing, had inadvertently become the Master (or Mistress, sorry) of Death, immortal. Obviously, Harriet had been almost destroyed by this information, she'd have to watch her family and friends die, only for Death to tell her that she would soon find certain individuals that, by a twist of fate, were also immortal, and that they would become her companions throughout the ages. Death also told her that there wasn't just one reality, just one world. There were many, and it was Harriet's destiny to travel to all of them and do many different things.

So, as she called Death after her discovery in this new world, he appeared to her with a smile on his face. "Yes, my Mistress?"

"I am in a new world, one without magic, one 68 years in the future." It was posed as a question, but both knew it was not. Nevertheless, Death nodded.

"Yes, my Mistress. But though there is not your kind of magic here, magic still exists. It exists in all the worlds, in many different forms.'

"Right. What is my next step here?"

"I do not know. I am unable to tell you what to do, but I can tell you what I think you should do."

Harriet resisted the urge to roll her eyes. It wasn't necessarily his fault, but Death was always so confusing when he spoke. "Then what do you think I should do, Death?"

"I think that you should find Nicholas Fury. He will help, and he will believe your story. Tell him everything." And then, without even letting her thank him, or ask him where she could find this Nicholas Fury, Death faded away.

Harriet did roll her eyes this time. "Thanks so much," she muttered sarcastically. Concentrating on Nicholas Fury, she apparated to his location. Only to find herself dodging bullets. "Come on!" she exclaimed. "I mean no harm, I only wish to help, and to find help too I suppose!" The bullets stopped raining down upon her, and with a huff, she summoned the ones that had hit her out of her, healing herself with several quick spells. She turned to find a multitude of guns trained on her and suppressed the urge to roll her eyes again. "Obviously those can't hurt me. Now, which of you people go by the name of Nicholas Fury?"

A tall, broad black man with an eyepatch stepped forward. "What do you want?" Harriet eyed his leather trench coat with distaste.

"I'd rather speak in private," she announced. "What I'm about to tell you can be very sensitive, and it would end up rather badly if it reached the wrong set of ears. If you need, I'll swear an oath on my magic and my life not to harm you."

The man eyed her suspiciously. "Swear it."

Smiling reassuringly, she held her wand to her chest and began the oath. "I, Harriet Lilith Potter, Mistress of Death, swear on my life and my magic not to harm Nicholas Fury as long as I believe he is good and/or trustworthy, or as long as he does not harm me. So mote it be." There was a flash of light and the oath was complete.

Nicholas Fury nodded to a woman and a man standing on either side of him. "Agents Hill and Coulson, take care of everything while I'm gone. I have a feeling this will take a while."

Harriet smirked. Nicholas Fury had no idea how right he was. She followed him to his office, where he locked the door. "Is it alright if I put up some privacy charms? They'll just interfere with the electronics a bit, make sure that nobody is able to listen in through both them and through physically being there. I can also cast some revealing charms as well. Make sure nobody is hidden in here,"

The man nodded. "Might as well. Stark always listens in. Hacks S.H.I.E.L.D. all the time too."

As she cast the charms, Harriet asked, "Who is this Stark? And what is S.H.I.E.L.D.?"

"You don't know who Tony Stark is?" he asked incredulously.

"No, I'm afraid not," she shook her head. "I don't even know who you are, not really. I was just informed that it would be a good idea to look for you."

"Are you from Asgard?"

"Asgard? You mean the realm of the Norse gods? That's real in this reality?"

"This reality? Explain."

"My name is Harriet Lilith Potter, as you know by now. I was born on 31 July, 1920 to James and Lilith Potter. James was a rich pureblood wizard, an officer in the British Magical Army during both the Great War and the magical war against Grindelwald. Lilith was a muggleborn witch, who fit perfectly into pureblood society. She became a healer, and both the fact that she worked and that she married a pureblood lord were huge scandals. They were killed on 31 October, 1921, and I was sent to live with Lilith's muggle sister - muggles being humans without magic - and her family. I didn't have much of a childhood. I was a slave, and I was abused in many ways. I entered the magical world at the age of eleven, and fought the Dark Lord Voldemort almost every year of my schooling. Voldemort, by the way, was the man who murdered my parents.

"I dropped out at the end of my sixth year to hunt for pieces of Voldemort's soul, which were scattered around England, and then on 2 May, 1938, the Final Battle occurred. I defeated Voldemort for the final time, and there was peace in the magical world. But just over a year later, World War II broke out in the muggle world, and, as the only thing I knew how to do was fight, I joined the British Magical Army just like my father once did, and I fought. In fact, I headed my own division, the Dragon Division. At the end of the war, I had nothing. My friends and family, even the Dursley's - my muggle relatives, that is - had perished during the war.

"And so, I decided to leave that world. I had become the Mistress of Death during the war against Voldemort, meaning I was immortal and thus able to traverse the many different universes and realities of universes. My home world had this … object, I suppose it was, called the Veil of Death. I stepped through it, and woke up here, in New York. There is no magic like I once knew in this world. There once was, I think, but something happened long ago, and now it is gone. There is a type of magic though. Anyways, Death told me I should go to you. He said that you could help me." He hadn't actually said that, but Harriet had inferred it.

Nicholas Fury regarded her silently for a moment. "Death is alive?"

Harriet laughed. "Alive? No. He is an entity though, just as life is, and fate, and time, and several other similar concepts. But Death is the only one who has a Master, and will ever have a Master."

"Why is Death the only one?"

"Because he was foolish. I shall tell you the story of why if you would like."

"Yes, I would."

"Once there was a river, a wide, fast flowing river. There was no bridge, and everyone who tried to cross it drowned. One day, three brothers happened to find this river, and they wanted to cross it. Death waited eagerly for them to attempt to swim across it, so they could drown and he could collect their souls. But the brothers were powerful mages, so they simply waved their wands, and they magicked a bridge over it. This made Death very angry, but he did not show this when he appeared before them in the middle of the bridge. He spoke to them, telling them how delighted he was that they were clever enough to magick a bridge above the river, that they each deserved a gift, a prize for escaping him.

"The first brother demanded a wand that could never be defeated, a wand more powerful than any other, for he had many enemies. Death fashioned a wand from a nearby elder tree, and presented it to the first brother. The second brother wanted something that could revive the dead, for the girl that he had wanted to marry had died young, and he wanted her back. Death picked up a stone from the riverbank and handed it to the second brother. The third brother however, he was wise. He asked Death for a cloak, one that would hide him from Death's gaze. Reluctantly, Death took off his own cloak, and the third brother took it.

"When the three brothers parted way, the first made his way to their hometown, where one of his enemies lived. He challenged his enemy to a duel, and when he was defeated, he made his way to an inn, where he bragged about his victory, and of the wand that he had been gifted by Death himself, an unbeatable wand that was more powerful than any other. That night, he stumbled into his bed, where he soon fell into a wine-sodden stupor. Attracted by the tales of the first brother's unbeatable wand, a thief crept into the first brother's room, and as he stole the wand, he slit the first brother's throat for good measure. And so Death claimed the first brother.

"The second brother made his way to his home, where he eagerly used the stone to call his love back to life. But the girl was sad and cold, because the dead do not belong in the world of the living. After a year of watching his love suffer, the second brother released her back into the afterlife, and he killed himself. And so Death claimed the second brother. Once he had the first two, Death searched for the third brother for years, but was unable to find him. It was only at the end of his life when the third brother took off Death's cloak and handed it to his son. He greeted Death as an equal, and, as old friends, they walked to the afterlife together. And it was then that Death swore an oath. The one that unites the Deathly Hallows shall become the Master of Death until the end of time. And so I became the Mistress of Death."

After a moment, Nicholas Fury spoke. "I suppose it's my turn then. I am Director Fury of S.H.I.E.L.D., the Strategic Homeland Intervention, Enforcement and Logistics Division. We basically deal with stuff like you: visitors from other realms, aliens. I can make you a real person in this world, and I can provide you with housing. I just require that you become a consultant for us. Meaning, if we are ever in need of your services, whether that be your magic or your skills in war, we will call you up and you at least consider our services."

"That is agreeable."

"Welcome to S.H.I.E.L.D. Miss Potter."