A/N: I'm not making money from this. This is J.K.'s world, I'm just playing in it.
The next morning her Muggle alarm clock went off at 10:00 AM, and she dragged herself out of bed and into the shower. She scrubbed her hair with shampoo and conditioner left by Dispater, and washed her body with soap. She shaved her legs and armpits, and applied moisturiser to her skin, before she slipped into her Armani suit, which was a light grey and she wore a black silk camisole with thin shoulder straps under the jacket. She made herself a mocha again, and while it brewed she tamed her hair with a drying charm and a few styling charms she had used in her Potter life. It now hung in loose curls around her face, and brought out the colour of her deep brown almond shaped eyes. She downed the coffee and shoved her pyjamas into her trunk and shrunk it down to fit in the pocket of the plain black robes she had bought for everyday use, made of Acromantula silk.
Casting her eye about the room, she made sure nothing was left behind. "Sirius, I'm going to pick up Harry now, and I'd like you to come with me. I have no doubt that Harry's owl Hedwig will want to meet you, and it would be a good time for you two to hunt while we shop." The tawny owl hooted and flew over to her shoulder. Alexandra slipped on her Louboutins and gripped the owl's talons, and concentrated on the corner of Privet Drive and twisted.
She landed with a crack on the corner of a fairly nice estate, with detached houses and decent sized lawns. Sirius was hooting indignantly at her and she giggled. "I know, I'm sorry, I'll warn you next time. Can you fly over to Number 4 for me, so I can find it?"
The owl huffed and obliged, gliding over to a house in the middle of the road. She sighed, and tucked a curl behind her right ear, and began to stride towards the house with purpose. As she approached the drive, she could hear shouting from inside and increased her pace, and reached out to knock sharply on the front door. The shouting ceased, and after a few moments of silence, Petunia Dursley answered the door. The thin woman looked her up and down in shock, and glanced back into the house, no doubt at her husband.
"Good afternoon, Mrs Dursley. May I come in?" Alexandra said pointedly, trying to glance over Petunia's shoulder into the house. The woman nodded without saying anything, and she stepped into the hall of the house.
"Can I offer you tea? Coffee perhaps?" stammered Petunia, trailing behind the witch.
"No, thank you, I'm quite alright. Is it okay if I take a seat? We have a lot to talk about." She replied, taking a seat on a light pink armchair. Petunia and Vernon sat together on the sofa, and Alexandra remained quiet for a few moments, until the silence was interrupted by Vernon.
"What do you want, woman? Coming in here, barging into our home! What do we have to talk about?" he said aggressively, glaring at her with piggy eyes.
"Mr Dursley, my name is Alexandra Potter-Black. I am twenty years old, and yesterday I became the Head of the Ancient and Most Noble Houses of Potter and Black. Yes, I am a witch." She stated, looking at both Muggles. When she said her name, Petunia became very pale, whereas Vernon's face began to turn purple with rage.
"So that's it then. You're one of those freaks, are you? Well, I won't stand for it! Not in my house. NOT IN MY HOUSE, I TELL YOU!" he yelled, getting to his feet and standing over her. Alexandra smiled, and extracted her wand from her pocket and twirled it around in her fingers.
"Mr Dursley, I would like to remind you of two things before you continue. First, the Houses of Potter and Black rank at the very top of our society, and I'm afraid this carries over to the non-magical world. I am to be addressed as Lady Potter-Black. My families are so prominent that her Majesty herself knows of both Houses." As she spoke she rose from her seat, her heels giving her a height above the portly man's. She drew on her pureblood heritage, and stood proud, allowing her magic to seep out a little, only enough to light her eyes up.
"Second, while your nephew is an underage wizard and is prohibited from using magic against you, I am a fully trained witch, with two years of curse-breaking under my belt. Now, you may continue, or you will allow me to speak to your nephew. Bear in mind that I don't actually need your permission, I'm just being polite. Which do you choose, Mr Dursley?"
The fat man had turned pale like his wife, and sat back down, staring at her wand. "Good. Thank you for your cooperation."
Alexandra swept out of the room, her robe billowing behind her, and she tentatively climbed the stairs. Harry had left his door slightly ajar, and she knocked gently. "Harry? Can I come in?" she asked softly, and waited for him to reply. When she heard a soft "yes", she pushed open the door. Harry was sitting on his bed, facing the door. She smiled at his messy black hair the same shade as her own, and met the piercing green eyes that looked at her with suspicion. Lily's eyes, of course. She herself had inherited James' eyes, how, she did not know, as her father had had grey eyes.
"Hi Harry. Can I sit down?" she asked, and he nodded. She took a seat on a rickety old chair by a desk. "You don't know me but I know you. I'm your cousin Harry, my name is Alexandra. I'm a Potter too." She said and watched his eyes widen in shock.
"Dumbledore said that I was the only living Potter." He said quietly, and she grimaced. "Well, I've been working in France for the past two years as a curse-breaker, so imagine my surprise when I got back here and I found my baby cousin all grown up and at Hogwarts!"
"The thing is Harry, there's a lot that Dumbledore hasn't told you. For one, the Potter family is actually what the Wizarding World calls an Ancient and Most Noble House. It means that our family is very old and very powerful. For each house, there is a Head and an Heir. In the case of House Potter, I'm the Head, and you are my Heir. I'm only the Head until either you turn seventeen, or I can keep it longer than that if you don't think you're ready. However, I'm also the Head of House Black. It's also an Ancient and Most Noble House, and the last Head was Sirius Black, your parents' friend. James and Lily though that the Headship of two Houses would be too much pressure, and seeing as Sirius hated his whole family he left it to me, as I'm the only other Potter who was eligible. With me so far?" she asked warily. It was all very complicated, and she wasn't sure she had explained it well enough. When he nodded, she grinned widely. I knew he'd be a smart one.
"Right, so because I'm your Head of House, I can be your guardian. I've already signed the papers, and Harry, I can get you out of here." She announced triumphantly.
He sat up straighter. "You mean it? You can take me away?" he asked eagerly, leaning forwards. When she nodded, the boy launched himself at her and wrapped his arms around her. "Thank you, thank you, thank you! You have no idea how much I hate it here!"
She laughed and pulled him into a hug. "Anytime, kiddo. And I mean it, you know. If you ever need me to be somewhere, I'll go, if you need something, I'll get you it. I promise." She whispered into his hair, and dropped a kiss on his head, which made him tighten his arms.
"Now, what say you we get this all packed up, eh?" she offered, pulling back from the hug slightly and he looked up at her. A grin split his face, and he pulled away and flipped his trunk open.
"I only got here yesterday, so I'm not unpacked yet." Harry explained, throwing books into the trunk and grabbing a jacket off the chair. "I take everything with me when I go to school, so that's it, I'm done."
She smiled, and tapped his trunk with her wand twice. It shrunk to fit in his jacket pocket, and weighed almost nothing, so she passed it to her cousin and he pocketed it. "Okay, now for the owls…" she muttered, crossing to his open window. "You have an owl too?" he asked, following her and looking out.
Alexandra stuck two fingers in a mouth and whistled. "Yep, he's a tawny called Sirius," here she winked at the boy, "I only got him yesterday though."
The distinct colour of Hedwig caught her eye, and she and Harry ducked as the two owls soared into the room. "Sirius, this is Harry; Hedwig, I'm Alexandra. Right, Harry, if that's everything, let's get out of this hellhole."
With that, they trooped out of the room and down the stairs where Petunia and Vernon waited, stewing with anger, in the hall.
"Mr and Mrs Dursley, thank you for your cooperation today. This is the last time you will see your nephew, but I can't say that you won't see me again. Good day."
Alexandra flicked her hair over her shoulder as she turned and strode out of the house, leaving Harry to say a brief goodbye. The two owls followed her after leaving droppings on the heads of both Dursleys, and she explained to them that they would apparate to Diagon Alley, where they would be free to fly around, and she would call them when they left for Potter Manor.
Harry joined her on the driveway, and she reached for his hand, which was accepted. Hand in hand they walked to the end of the street which was more secluded from Muggles. She explained to him their game plan for the day: lunch, Gringotts for the Heir ritual, bookshop, stationer, Twilfitt and Tattings, then Muggle London for casual clothes, Florean's for an ice cream, picking up other accessories and then straight to Harry's home of choice.
Harry smiled at his cousin. He couldn't believe his luck that she had come and rescued him from the Dursleys and soon he would have a new home and control over his life. He had a feeling that he and Alexandra would take the Wizarding World by storm, and little did he know that he was absolutely, undeniably right.