Disclaimer! I hereby swear upon my magic and my life, that I do not own Harry Potter nor do I own Marvel. They are owned by J.K. Rowling, Warner Bros., Stan Lee, and Disney respectively. So have I sworn so mote it be. Now onto the story!
NOTE: This story is going to be pretty AU, it is a crossover and the timelines will diverge from Harry Potter canon greatly but, the MCU timeline is going to be pretty consistent for the most part aside from Steve arriving a lot earlier than in the films.
-ooOoo-
"Good luck Harley Potter."
Harley Jade Potter was only fifteen months old when her parents died on Halloween of 2001. Of course, she was completely unaware of this fact until she turned eleven. She was also unaware of the fact she was given the ridiculous moniker that was The-Girl-Who-Lived. She was left on the doorstep of her aunt's house, who happened to be her mother's sister. When Petunia Dursley opened the front door the morning of November 2nd, she let out a shrill shriek that woke the infant unceremoniously. Petunia was able to calm it down enough so that her cries could not be heard by the neighbors and draw unwanted attention to Number 4 Privet Drive.
Hearing her scream of distress, Petunia Dursley's husband, a beefy man with a mustache like a walrus rushed to the entry hall of his home.
"Tuney! What is it darling? What's wrong?" Vernon's worry for his wife's well-being increased when he saw how pale she was. "Tuney?" She was gaping, wide-eyed, and pointing at something on their front step. It was then he realized that it was a bundle of blankets and in that bundle was a baby girl. Although the baby was just part of the problem. It was the letter that seemed to be causing more of her distress. Petunia Dursley had seen that handwriting before. She had hoped to never see it again. It was very loopy and a tad extravagant, and it was addressed to her and her husband.
At the moment Vernon Dursley was the rational thinker, quick as he could he picked up the small basket in which the baby lay and, brought it inside his home for the first and last time.
-ooOoo-
The letter lay in the center of the dining table, and Vernon and Petunia Dursley were staring at it with disgust and contempt. How dare those freaks just leave a baby they never asked for on their doorstep? Petunia was upset about her sister's death and she hid her grief well, but this was her family too. The letter explained about the Dark Lord known as Voldemort, how he was after her sister, brother-in-law, and niece. How he found the house they were staying in and he murdered them both where they stood. How when he tried to murder Harley the curse rebounded and defeated him. And now as her only living family that she was to go to them. Petunia was able to calm Dudley down enough to leave him in his crib with a stuffed toy. At the moment she was holding her niece in her lap for the first time. She kept her at a distance however but tightened her grip so she wouldn't fall off her lap.
"They can't possibly just leave her here!" Vernon stated angrily.
"Well, what are we supposed to do? Get rid of her?" Petunia snapped back.
Vernon looked up at her. An idea was growing in his head. A first for the fat walrus. Petunia noticed the odd look on her husband's face and his sudden silence.
"Vernon?" Petunia questioned her husband quietly.
He said nothing for a moment and then finally looking at his wife he said in an almost whisper, "What if we can get rid of her? Not permanently but, far away from us before anyone here even knows she exists?" Despite the situation, Petunia felt herself leaning forward intently. "Whatever do you mean? Vernon… what are you planning?"
He hesitated a moment before speaking. His plan sounded crazy in theory but, with the right manipulations and the right timing it could turn out perfect for the Dursley's. "Petunia, I know that this may sound mad darling but," he took a calming breath, "I have a business trip coming up. One that I can take my family on," Petunia couldn't tell where her husband was going with this plan, but she gestured for him to continue speaking. "What if… we took a baby with us and left the other baby here?" He paused then watching his wife's face for a sign of reaction. He could almost see the gears turning in his wife's brain as she put two and two together. Her face looked shocked and unsure at the idea he was presenting. They stayed silent for what felt like forever but it was only a few minutes before the couple came to a silent decision. Petunia glanced at her niece sitting quietly in her lap. They knew how to get rid of the abomination that was Petunia's freakish sister's baby.
-ooOoo-
It was the Monday after the Dursley's found their niece on their front step when 's plan came to fruition. On his way home from work he carried two plane tickets. Petunia had already dropped Dudley off with Vernon's sister Marge. She had packed a diaper bag with the necessities for a baby. She had gone out the previous day to buy cheap little onesies that while meant for a boy would be able to disguise her niece. Her hair was a little on the long side and that hideous scar was annoyingly distinctive. Petunia calmed herself and came up with a simple solution. She found a little red beanie to cover up both problems. On the sixth of November, the Dursley's were air bound for New York City. Getting through security was pretty much a breeze. Vernon suggested putting a medical mask over the baby so she would be harder to describe, but they used the pretense of fearing for the baby's health. Really it was just another tactic to keep the baby's face hidden.
Petunia could feel her nerves kicking in when the passports were being looked over. However, she was practiced in hiding her emotions. She was worried about her husband though, she knew that his emotions were worn on his face quite literally. She'd seen his face change colors like a traffic light and hoped beyond hope that he could just keep it together. She was very surprised that he could. They made it through though, and when they were far enough from the TSA agent Petunia Dursley was able to breathe again.
She just hoped she'd be able to hold it together for what she had to do later that night.
-ooOoo-
Petunia Dursley loved her husband dearly. After all, she had married him, and she had his child. However, Petunia Dursley knew that her husband wasn't the sharpest knife in the kitchen, which is exactly why she was the one doing this highly illegal task. It was late in the evening, possibly nearing midnight, but Petunia Dursley was out and about in Manhattan carrying a duffle bag that contained her sleeping niece, looking for a place to drop it off. She was on a semi-dark street and it was quiet. She had just passed a small, rundown building named Fogwell's Gym when she heard a door open behind her. Panic swelled inside of her as she looked for a possible escape, she couldn't be caught. She looked left to right and saw an alley next to the gym. She ran into it and tripped, dropping the duffle. She heard footsteps approaching and quickly got to her feet. She ran a little further down the alley before hiding behind a dumpster. She heard a man's voice call down the alley, but she refused to make a sound. She heard footsteps approaching but then her niece in the duffle bag began to cry. She waited with bated breath as the footsteps retreated to where she dropped the bag. She heard the man gasp and her niece crying louder, but then it started to grow softer. She took a chance and peeked out from her hiding spot. She saw a fairly young man, with his back turned to her, holding her niece. She didn't know if it was five minutes or an hour but she saw the man, still holding her niece stand up slowly pick up the duffle bag and she watched her niece be carried away from her life.
-ooOoo-
Steve Rogers was walking out of the gym after a restless night. He went through three punching bags this week. Ever since he woke up from the ice most of his nights were blank. There were no dreams or nightmares, just a dark, empty space. Frankly, he preferred it that way. As he walked out of the gym he heard a noise in the alley, and it sounded like a person so he went to check it out. He noticed a duffle bag by the entrance of the alley but chose to ignore it in favor of going a little further down until he heard crying.
He turned back, startled by the sudden crying and realized it was coming from the bag. He backtracked and was thoroughly surprised to find what was inside. A baby girl (though he couldn't tell yet) was crying inside the bag, she had untidy black hair that stuck out in every direction. Her eyes had opened up enough for him to tell through the dim light of the alley that they definitely weren't brown. Most intriguing however was the lightning-shaped scar on her forehead. Gently he picked her up and he carefully started to rock her. She calmed down but was still sniffling.
He didn't know what made him do it, hell he didn't even know why, or how long he stayed in that spot just holding this child who was all alone in the world, just like him. It was at that moment he made up his mind. He stooped down to pick up the bag he found her in and adjusting the baby girl in his arms he set off with her to his apartment.
"Don't worry kid. You're not alone."