Disclaimer: I do not own Harry Potter, only most of the plot and the OC, and I am not making any money from this story

Summary: Prequel to the Black Riddle. Follow the journey of Rosanna Alison White as she travels into the World of Harry Potter, but there are dark times a head of her. Can she overcome them with her new friends, the Marauders? SB/OC

'Thoughts'

"Speech"

Previously

"Can I ask you one more question?"

"Sure, go ahead"

"It's just that…you said that you come from a different world where no magic exists, right?"

"Yeah?"

"If that's so, then how come you can do magic?"

It was silent for a while…until "WHAT?"

Chapter 5

"Y-yo-you must be mistaken. I can't do magic. People don't even have magic where I come from. It-it-it just doesn't exist in my world. You have to be wrong" Rosanna sat up on the settee and looked pleadingly into Sirius's eyes.

But Sirius replied "What do you remember when I rescued you from my house?"

"What does that have to do with anything?"

"Just answer the question"

Rosanna thought for a moment, and then replied "I remember you bringing me up to the kitchen, then you and I had an argument and I started ranting. There was then a large pain in my head and stomach, and then…nothing"

Rosanna looked up at Sirius confused

"How does this explain anything?"

He gave her a knowing look "When you were ranting, even I could tell that you were pissed, and I mean VERY pissed. Just before you collapsed, I felt a surge of power come from somewhere and all of the glass in the room shattered." He gave a sigh and continued "It must have been from you as there is nothing that powerful in that house and also there was no one else in there except for me and you. Your anger must have unlocked some hidden power within you, but I have no idea where it came from or how you have it"

Reeling from the information that she had received, Rosanna fell back on the settee with her hands covering her face. One thought kept flickering through her mind 'How is this possible?' She was silent for quite a while, while the boys were looking on, Sirius trying to think how to deal with the situation, and James trying to understand what on earth had just happened here. Eventually James broke the silence as he stood up; bid the other two good night and headed for the stairs.

After James had left the room, Rosanna's hands uncovered her face, and she turned to look at Sirius, who appeared to be dozing in one of the armchairs. Even though she was still shocked over what she had just found out, she was too tired to do anything about it now, so she decided that she would do a proper freak out tomorrow. So she got up from the settee and silently approached Sirius. She glanced over him, whilst he slept, eyes closed and a ghost of a smile upon his lips. His hair was staring to drape across his face, so Rosanna lightly brushed the hair out of the way with her hand, trying not to wake him up. But, as they say, some things don't go the way we want them to, and that little action caused Sirius to stir in his chair and he opened his eyes slightly.

"What, Rosanna?"

Rosanna gave a smile. "I'm off to bed, but if you're tired I would move from that chair"

Sirius gave a slight groan and turned over, while he mumbled "Comfy" causing Rosanna to giggle. Sighing she bent down and whispered in his ear "But you'll regret it in the morning". This caused him to groan again, but it did the trick as he slowly got up off the armchair and stretched, before heading to the stairs, while mumbling a "Good night" in Rosanna's direction. Even though Sirius couldn't hear her, she whispered back "Good night Sirius". She then resolved to go up to bed herself and so traipsed up the stairs, trying to remember where her room was located. Eventually she found it and entered the room. From what she could see, the bed sheets were already turned down for her, and the fire place was smouldering slightly as the fire went out. Changing into some pyjamas she found in the wardrobe, Rosanna got into the bed and fell asleep almost instantly.

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

Rosanna woke to the sound of shuffling and muffled whispers in her room. Keeping her eyes closed, she strained her ears to try and pick up what they were trying to say.

"Shush. You'll wake her" she assumed that must be James

"I just stubbed my toe"

'That's gotta be Sirius' she thought

"You'll stub more than your toe if you don't shut up"

It then went quiet, which unnerved Rosanna a little. Suddenly she shrieked and jumped about 5 foot in the air, as she was doused with a bucket of ice cold water. Drenched, she turned towards the pair of pranksters, who were rolling around in laughter on the floor. When they finally got themselves together again, they noticed Rosanna aiming a death glare at them.

"Have a nice sleep did you Rosanna?" they both asked simultaneously, both faces bearing smirks

Rosanna took a step towards them, and their smirks wavered a little.

"You know guys; it's not nice to wake a girl up from her beauty sleep" she said in a sickly sweet voice

By this point the boys were backing away towards the door, all the while keeping their eyes on Rosanna.

She smirked slightly before continuing "And I'll have you know, that I have a very bad temper in the morning, especially when someone wakes me up."

They were almost at the door now, ready to pelt it down the corridor at a moments notice.

"Do you know what happens to the people who do?"

"N-no"

"They are paid back…with interest"

With that, the boys darted out the room and out of sight of Rosanna. She smirked to herself and decided to go and get ready for the day, thinking about how she should get her revenge on those two. About an hour later, she was dressed in a pair of black boot leg jeans, with ankle high leather boots, about 2 inches high, and a grey and silver top. She wore a matching black and silver necklace and had put up her hair in a stylish messy bun. Checking herself over in the mirror, she then headed downstairs for breakfast. When she reached the bottom of the stair case, she noticed that James and Sirius were standing in corner near the living room. But they hadn't noticed her yet, so she quickly hid herself behind the stairs, all the while smirking. She had planned this while she was getting herself ready, her revenge on those two boys. She had figured that most of the spells in Harry Potter were Latin, which was quite handy as Rosanna was fluent in Latin. Also, because she now had magic, she could try one of the spells that she had come up with when she was back in her own world. She had also figured that the underage magic law wouldn't apply to her because she was over the age of 17. So she closed her eyes, while focusing her thoughts on James and Sirius and murmured the spell's incantation "Align capillis color green and silver". Opening her eyes, she looked around the corner and noticed that James and Sirius had gone, so she decided to try and find the kitchen for breakfast. When she eventually found it, she was informed by one of the house elves that breakfast would be served in the informal dining in 15 minutes, so she headed in that direction instead.

Entering the room, she noticed that Charlus and Dorea were already seated there, Charlus reading the Daily Prophet and Dorea sipping a cup of tea. Rosanna walked over to the table and sat down next to Dorea.

Dorea glanced up at her and gave her a smile.

"Good morning Rosanna. Did you sleep well?"

"Good morning" She replied "Yes I did, until I was rudely awoken this morning by your charming son and his friend"

From the roll of Dorea's eyes and the slight chuckle heard from Charlus behind his newspaper, Rosanna could tell that they were quite used the boys' antics.

"What did they do this time?"

"They thought it amusing to see how I would react to ice cold water"

Dorea looked a little shocked, but then shook her head and chuckled slightly. "Ah, those boys. They never get tired of pranking someone. I'm just sorry that you ended up being the target this time"

"It is of no consequence. Wait…hang on a minute, it is of consequence. But don't worry about me being the target, my revenge upon them will be seen soon enough"

"Dare I ask?"

Rosanna just gave her a smirk and replied with "You'll see". With that, Rosanna poured herself a cup of tea and waited for the boys to enter the room. A few minutes later, she heard voices coming from the corridor. She turned and had to stifle a snort of laughter as she saw the pair of them. Instead of the black hair that all were so used to seeing, both of the boys' hair were green and silver stripes.

"Morning" they both greeted everyone. Dorea looked up to answer, but her words were lost when she saw the boys' hair. She stared at them for a moment or two, before bursting in to giggles. Charlus put down his newspaper, to see what all the fuss was about and caught a glimpse of the boys' before covering his mouth with his hand trying to smother his laughter. The boys' looked on bewildered, not knowing what had caused the Potters to break down in fits of giggles at the breakfast table.

They turned their heads to look at Rosanna, and they saw her smirking in their direction. She winked at them and said smugly "While I am glad that you are showing the support to Slytherin house, did you really have to go that far?"

"Huh?" Sirius replied, until he heard an undignified squawk from James. He turned to James and was about to ask him what that was, when he caught a glimpse of James' hair. It was green and silver. His eyes went as wide as dinner plates and he tugged around a piece of his own hair and saw that it was the same as his best friends. This caused him to let out an undignified squawk of his own and both of them rounded on Rosanna, who was now in a fit of hysterics at the table. While she was laughing, Rosanna could see that James and Sirius were aiming death glares in her direction. Once she has calmed down, she smirked at them and said "What goes around, comes around boys".

But before the boys could retort, Charlus Potter interrupted them "Well, that was certainly a bright start to the morning. But I have to ask one question Rosanna, how did you succeed in this prank without magic?"

Rosanna turned to Charlus and replied "Well, sir, late last night after you had gone to bed, Sirius decided to inform me of something that he had forgot to mention earlier" She looked pointedly at Sirius, who put his hands up in surrender before saying "Hey, it's not my fault I forgot this minor detail. It's not everyday that someone from another world drops into our lives"

"Would you like to continue Sirius, as you seem to know more than I do about this situation? Even I'm not sure that I've got my head around it yet."

Sirius rolled his eyes and gave Rosanna a grin. He then turned his attention to the elder Potter's before continuing where Rosanna had left off. "When I rescued Rosanna from my parent's house, I took her up to the kitchen and was about to try and find something to ease her pain. At that point I was about to inform her of my name, before she whispered it under her breath. After that…well, you all know what my temper is like, but I am nothing compared Rosanna when she is pissed. After I blew up for a few seconds at her knowledge, she then ranted for a few minutes before she doubled over in pain. At that point all of the glass in the room shattered and I felt a powerful surge of magic"

He looked up at the Potter's shocked faces before continuing "I knew that there was nothing, person or object, that held that much power in that house, so I naturally assumed that it came from Rosanna, though I still don't know how she could have come to posses magic"

While Dorea was still in a shocked state, Charlus actually looked quite thoughtful, as if he was trying to figure out this mystery by himself.

After a few minutes of silence, Charlus looked up at Rosanna before saying to her "I think there is a way to determine how you have come to posses magic Rosanna"

Rosanna looked hopefully at Charlus before replying "How, sir?"

Charlus sighed, he glanced at Dorea, whose face possessed a knowing look. He leaning over and whispered something in her ear, before she nodded slightly, as if agreeing to whatever he had said to her. Turning back to Rosanna he continued "At Gringotts, there is a ritual that can determine the heritage of any living person with magic. This could be used on you, so we could find out how you come to have magic"

Rosanna's face broke into a huge smile with this piece of information. She had always been interested in her family's heritage, but she had never had the resources to do it with.

"Will I be able to do this? If so, when?" she asked eagerly

Charlus smiled at her eagerness and replied "Yes you can do this. I can floo Gringotts after breakfast and try to book an appointment for this afternoon." At this revelation, Rosanna darted out of her chair and before Charlus knew it, she was hugging him in thanks, but it only last for a moment before Rosanna let go and stood back sheepishly. "Sorry sir"

Charlus recovered from his shock before rolling his eyes and said "No problem Rosanna, and call me Charlus"

At that point, breakfast appeared at the table. It was filled with so much food that Rosanna didn't even know where to start. There was bacon, eggs, sausage, black pudding, toast, kippers, porridge and even more. She decided that she wasn't in the mood for anything rich that morning, so she reached for the porridge and spooned some into her bowl and sprinkled some sugar on it, before grabbing two slices of toast with butter, put them on the plate beside her and began eating. There was only a light chatter at the breakfast table, as most of them were too immersed in their food. When Rosanna had finished, she waited for everyone else to finish. When the table was cleared, Charlus excused himself before going to his study to make the floo call to Gringotts. Dorea also left the room, saying that she was going for a walk around the gardens, so this left Rosanna in the company of one half of the Marauders and this half had just rounded on her. Sirius was actually glaring at her and they both walked up to her slowly before falling to their knees in front of her. Sirius gave Rosanna the wounded puppy look, which had Rosanna struggling not to fall for. But one thought did penetrate her mind 'Awww, he looks so cute like this' It was James who broke her from her thoughts with his fake pleading.

"Please release us from this torture"

But Rosanna did not budge

"Oh but James, green and silver suit you so well. I think I might leave you both like that"

"Nooooooooo. The humiliation." Whined Sirius

"Oh, stop being such a drama queen Siri."

"But my beautiful hair is ruined. I look like a slimy Slytherin. Oh, the shame" He put the back of his hand to his head and pretended to look faint. By this time, James had already gotten to his feet and was standing next to Rosanna. Rosanna glanced at James and whispered so that only James could hear "Does he always act like this?" James replied "Unfortunately for us, it's quite often."

When they had finished talking, they both noticed Sirius had stopped his whining and was pouting on the floor. Rosanna folded her arms and giggled before saying. "Hey, stop pouting Siri. You seem to love pranking others, but hate it when the tables are turned don't ya?"

"Shut up"

"Feisty, feisty. Its no different to what you guys do to people at Hogwarts, only this time, it is you two who are the victims, rather than the culprits. And I thought that Gryffindors could take whatever was thrown at them?" She looked expectantly over at them.

James sighed at her and replied "I suppose we can deal with it until it wears off, right Sirius?" he directed the last bit at Sirius sharply, who gave a short nod in response. James turned back to Rosanna and asked "How long until it fades?"

This got Rosanna smirking "Oh…about a week"

"A WEEK?" squeaked Sirius

"Afraid to go out into the public looking like that Siri? Are you sure you are a Gryffindor?"

Sirius didn't reply and just ignored her, while pouting.

James decided to break the tension by saying "So, who wants to go flying?"

This got Sirius to brighten up and he was on his feet in a matter of seconds, looking like he was raring to go. But Rosanna looked quite wary, and decided to inform James of one minor detail that he seemed to have forgotten.

"Urm…James?"

"Yeah?"

"You do realise that I have never ridden a broomstick before don't you?"

James didn't look too worried about this "That doesn't matter. I can easily teach you. It's easy once you get the hang of it"

Rosanna relented "Ok, fine"

James's smile widened and replied "Brilliant", before slinging his arm around Rosanna's shoulders, whilst trying to lead her out. But Rosanna pushed the arm of her shoulders and looked at James before saying "Was that merely a platonic gesture, or was there something more to it ' cause I know your handsome and all-"

"So you noticed?" interrupted James grinning

"Course I noticed. Even a blind a person could see it, but, sorry mate, you're just not my type. Anyway, you are more of a brother than anything else and incest is not my thing."

"Ah, fair enough. It was just platonic. I have my sights set on only one girl at the moment"

"Evans"

"Yup"

So James slung his arm around her shoulder once more, while directing her outside towards the quidditch pitch. Sirius had just excused himself, saying that he had left his wand in his room. While they were walking James asked "Just out of curiosity, who is your type?" Rosanna raised an eyebrow at this and replied "Isn't that a bit personal?" James just smirked before saying "Long dark hair, grey brooding eyes, carefree attitude, am I getting warm?" Rosanna looked away pointedly, while mumbling "Shut up", but James could see the blush forming on her cheeks.

"Doesn't matter, I'm only teasing"

Rosanna glared at him playfully "So not funny". They were silent until they reached the broom shed, where James took out 3 of the brooms that resided there. He looked around to see if Sirius was back yet, and saw him on the other edge of the field walking towards them. He handed a broom to Rosanna and instructed her to lay it on the ground, which she did.

"Now, put your right hand over the broom and say 'Up'"

Rosanna knew confidence played a part in this, so she gathered it up and looked down at the broom before saying "Up", with which the broom shot up into her hand. James then showed how to mount the broom and how to grip it properly, before showing her how to hover with a demonstration of his own. Sirius soon joined James in the air and gave helpful tips when he could. After about half an hour, Rosanna could fly pretty well around the pitch. She loved the feeling of the wind in her hair and the adrenalin pumping through her veins as she flew. James and Sirius soon joined her on her flight when she decided she wanted to try some tricks, so did some sharp turns and loop the loops. Then one thought popped into her mind, which got her grinning. She took a sharp dive downwards, gaining speed as she flew. It seemed like the ground was rising up to meet her, and when she was merely 2 feet from the ground, she pulled up sharply and flew upwards. She then changed direction and headed to James and Sirius, who were looking at her in amazement.

She looked at them in confusion and said "What?"

James was the first to answer "What was that you just did?"

"It was the Wronski Feint"

He just looked at her in shock before saying "Do you have any idea how hard that is to achieve. Even I can't get that far from the ground without crashing"

Rosanna raised an eyebrow "Huh, really?" looking impressed with herself.

Before anyone could say anything else, a voice from the other side of the pitch caught their attention. It was Charlus. James, Sirius and Rosanna walked briskly over to him to see what he wanted.

"Yes, dad?" James asked when they reached him

"I have an appointment booked for Rosanna for the heritage test. But the catch is that it we have got to be there in 15 minute, so go and put your brooms away and meet me in the living room by the fireplace.

Doing as they were told, the group put away their brooms in the broom shed and hurried over to the living room, where Charlus and Dorea were waiting for them. Charlus turned to Rosanna and said "Dorea will go first to show you how to use the floo network"

Rosanna watched as Dorea grabbed a handful of floo powder and tossed it into the flames before stepping into them and saying clearly "Diagon Alley" and then she disappeared. Charlus went next, and then it was Rosanna's turn. She copied exactly what Dorea and Charlus had done, grabbing the floo powder and tossing it into the fire, stepping into it, and saying in a clear voice "Diagon Alley" before her world started spinning. A few seconds later she stumbled out of a fire place. Dusting off her clothing, see looked around and saw, for the first time her life, Diagon Alley.

But she didn't have time to marvel, as she had to move out of the way of the fireplace to let James and Sirius through. When they were all present, they briskly made their way over to Gringotts through the crowds of people surrounding the shops within the alley. Eventually they made their way through the crowds and into Gringotts. Charlus approached one of the goblins and spoke to them for a minute or two before gesturing the rest of the group to follow him. They were all led into a private room, where a goblin was waiting for them. His emotionless face glanced over the group, before saying "Shall we begin?"

/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

Sorry about the wait for this chapter. I hope it's alright. I know, I've left it at a small cliff hanger again. What shall Rosanna's heritage test reveal about her? Shall we discover why she now posses magi, but did not in her world? We shall see. Reviews are very much appreciated and constructive criticism is welcome.