1. Chapter 1

**Disclaimer: I do not own BtVS or Harry Potter. Those belong to Josh Whedon and the lovely J.K. Rowling.**

**Summary: When Xander and Izzy were ten, Izzy learned that she needed to move back to England, the birthplace of her father, to learn to control her magic. So, reluctantly, she heads for Hogwarts, leaving her cousin behind. Now, six years later, she's back and Xander is pissed. She stopped writing him after the return of Voldemort, but according Xander, he hadn't gotten any of the ones she _had_ written. Who was keeping Izzy's letters from Xander? And what's this about vampires? Watch as Isabella and Xander are thrown into the chaotic world of the Slayer, even as they try desperately to find the one behind the letter theft and why.**

* * *

Xander felt his jaw drop when one of the two new students at Sunnydale High entered his History class. She was short, with a pixie-like frame and long, flaming red hair pulled up in a ponytail atop her head. She wore a dark red peasant blouse, an acid green gypsy skirt that fell to her ankles and a pair of sandals. Her crystal blue eyes darted around the room until they found his face. He could see the pleading there and nodded tightly, anger and, he thought, long resolved feelings of resentment and abandonment overtaking him. She returned the nod with a small one of her own before taking the only empty seat in the room. Directly behind him. Xander felt the overwhelming urge to turn around and wipe the downcast look off his cousin's face. However, he refrained. After all, the feeling of abandonment was not unfounded. She and her mother, his aunt Sarah _had_ abandoned him. They'd left for England and never looked back. They'd never called, never written, never visited. Just left one afternoon and never came back. Until now. Half-way through the class, the teacher assigned a group project. All the boys in the class converged on the girl. _His_ cousin. Xander saw red and quickly intercepted them all by turning around and asking himself. He grinned easily at her.

"Hey, Iz, you want to be my partner?"

She looked up and stared, too stunned to speak. His gut twisted at the shyly surprised expression on her pretty face as she smiled hesitantly and nodded.

"Thanks, Xan." she murmured lowly. He inclined his head, his grin now forced.

"No problem, Carrot Top."

She beamed before ducking her head and continuing to take notes. His task of keeping his perverted classmates away from his little cousin accomplished, Xander turned back to the front of the room, glaring at anyone who hovered hopefully near their desks. Behind him, he heard a quiet giggle from his cousin and turned to face her again, his eyes narrowed. Her eyes were wide and her hand covered her mouth.

* * *

Isabella Prewett nervously stepped into the History classroom, her eyes scanning the other students until they landed on the stunned face of Alexander Harris. Her heart clenched at the hurt in his usually warm chocolate eyes. He probably hated her. And he had every right to. She hadn't written to him since they were fourteen. She'd disappeared six years ago to England and hadn't written to him for one. But it had been too dangerous to write before then and it had been impossible to call because magic reacted badly with electricity. Hopefully she could get him to understand and they could be as close as they used to be. She, reluctantly, took the empty seat behind her cousin. Half-way through the class, she tensed when most of the boys in her class surged towards her after the teacher told them to pick a partner for their class project. She couldn't have been more relieved, if slightly shocked, when Xander turned around and asked her to work with him. She giggled quietly when he turned around and started glaring at the other boys. Her eyes widened and she slapped a hand over her mouth, hoping desperately that Xander hadn't heard her. She knew her prayers weren't answered, however, when he turned to glare at her. He had heard her then. Oops. She wasn't reassured by the mischievous, playful look in his eyes. That look usually meant that she was going to be tickled. Mercilessly. She whimpered, causing him to smirk. Then he turned back around. Iz groaned softly and let her head hit the desk. She was doomed. She glared at her cousin's back when she heard him chuckle, but otherwise ignored him.

* * *

Willow glared at the new girl for stealing _her_ Xander. She had wanted to work with Xander on the class project. She had hoped that if she spent enough time with him that he would eventually realize that she was the one for him and ask her out. But the new girl had interfered – and Xander knew her name! It was awful! She had to get him away from her. Talk him into switching partners before he fell for her. And why wouldn't he? She was stylish and pretty like Cordelia. She was probably just as snooty as Cordelia too. Huffing to herself, she angrily agreed to work with the boy next to her.

* * *

Iz anxiously followed Xander out of the room and down the hall. Suddenly, he grabbed her arm and jerked her into an empty classroom. He slammed the door, facing her with a frown and his arms crossed.

"Why didn't you write or call?"

She bit her lip, not sure how to explain.

"You remember how Mum told you I was going to England to learn magic?"

He nodded tightly, his expression blank.

"Well, when we tried to hook up a phone in the house were staying at – it exploded." she explained with a sheepish look on her face. He stared at her for a moment. Then snorted. Loudly. She stuck her tongue out at him. For a moment, it was like old times. Then he sobered and raised a brow at her.

"Why didn't you write then? Six years and not a single letter."

She gaped at him.

"I did write! We both did! Daily!"

"Then why didn't I get any of them?" he demanded angrily. Tears filled her eyes as she fought not to flinch. Her mum's last boyfriend had been rather fond of beating her or throwing her into walls when he was angry. She hadn't been around Xander since they were ten. She had no idea how he would handle his anger.

"I don't know! But I wrote them! I even copied all of them just in case they got lost on the way there or something! But you never wrote and told me you didn't get them so I thought you had and were too angry to respond!" she cried. Stunned by the admission, Xander froze.

"Show them to me." he commanded after a moment. She rolled her eyes.

"I didn't bring them to school with me Xander. I left them at home." when he said nothing, she took a step towards him, stretching her hand out beseechingly. He stepped back.

"Xander, I swear to you on my life, my magic, and my name – I wrote you as often as humanely possible up until a year ago."

They stood in silence for a moment, the bright light that had flared when she made her oath slowly fading.

"Why'd you stop?" he asked abruptly. She sighed, wringing her hands as an alternative to running one through her hair and messing it up.

"At the end of my fourth year, the man who killed my father was resurrected. They're still fighting him back in England. After he had risen again, Mum joined a group called the Order of the Flaming Chicken –" she blushed, "– I mean – the Order of the Phoenix and it became too dangerous to write to you without letting them know where you are. I didn't want them to hurt you and they would have had they known you exist. I'm so sorry Xander. You have no idea how sorry I am. I've wanted to come back since we left. Everyone in England is awful. I missed you like hell." she smiled faintly, "Though two of my cousins from over there a lot like you." she told him. He raised a brow.

"How do you mean?"

She grinned.

"Oh... a certain disregard for not only the rules but the teachers and their school work as well. And an uncanny ability to know when a situation is too serious and everyone needs a laugh to help them relax." She sighed sadly. "I wish you could meet them."

Finally, Xander seemed to forgive her – because he crossed the room and took her in his arms.

"God, Izzy, I've missed you." he breathed into her hair. She buried her face in his chest, taking a moment to breath in the musky scent that was purely Xander. She wound her arms around his waist, snuggling into his embrace. She was rather reluctant to let go, but the bell rang and she, regretfully, stepped out of his arms. She smiled ruefully at him.

"We need to get to class."

Groaning, he opened the door for her, snagging her around the waist and kissing the top of head as she passed. Izzy smiled. She had her Xander back. He grinned at her.

"C'mon. I'll show you to your next class and we can see how many people think we're dating before they realize that you're my cousin."

She wrinkled her nose in disgust, tricking a laugh from Xander. She had forgotten how annoying it could be to live in a small town like Sunnydale. Of course, rather few of the town's residents knew they were living on a Hellmouth, and therefore none of them knew all of the gossip and horrors the little town had to offer.


	2. Chapter 2

**Disclaimer: Anything recognizable in this chapter belongs to Joss Whedon.**

* * *

Xander had, of course, been right about the populous of Sunnydale thinking the two cousins were dating. Isabella, however, quickly stomped on those rumors the first time someone confronted her about it. A rather ditzy looking blonde walked up to her after lunch, twirling a strand of hair around her finger, and asked abruptly.

"Are you and Xander dating?"

Izzy immediately began gagging. She stared at the girl incredulously.

"You realize that you just suggested incest, right? Xander's my _cousin_."

The girl blushed and several members of their audience looked at their feet.

"I-I'm sorry, I didn't know –"

Izzy, however, merely waved her off.

"It's fine. It's been awhile since I've last been in Sunnydale, so it's understandable that you lot would forget me." she said with a grin. The girl frowned.

"You've been in Sunnydale before?"

"I know it's been six years, but I haven't changed that much have I?" she asked, bemused. Someone from the crowd gasped dramatically and stared at her with wide brown eyes.

"Izzy Prewett?" she demanded incredulously. Izzy's grin returned.

"Hiya, Cordy."

Cordelia Chase, tall, brown haired, and beautiful, stepped out of the crowd and snagged the ginger girl by the elbow, quickly walking her down the hall and away from the others. Izzy sighed as she was once again dragged into an empty classroom by an angry/upset person. As soon as they were alone, Cordelia turned on her former best friend. _Time to start begging_, the witch thought with a sigh. She opened her mouth to speak, but Cordelia beat her to the punch.

"Why'd you leave? Why didn't you call? You swore you were my friend and you left me! Why?"

Sighing in frustration, she gave into the urge to run her hand through her fiery hair.

"Cordy, you wouldn't believe me if I told you – but I did write. Everyday. Just like I did with Xander, but for some reason, someone stole the letters before they reached their destinations. I'm so sorry, Cordy. I wanted to come home the second I left, but my father's dying wish was that I go to his old boarding school. So I did."

"Why won't I believe you?" she demanded. Thinking quickly, she remembered that the American Magical Government, of which she was a citizen, wasn't as strict about it's Underage Magic laws so long as there was minimal chance of exposure. Whipping out her wand, she conjured a chair and transfigured a nearby desk into a cat. Cordelia stared.

"W-what the heck?!" she demanded. Wincing, she closed her eyes and took a deep breath.

"Cordy – I'm a witch."

* * *

In a dark room in sleeping house, a figure sat, contemplating the news he had just received with a glass of firewhiskey in his hand. The bitch had left. He had supported her and her daughter and she just packed up and left. While he had been out on a mission for the Order, no less. No note, no reason why. She had just left. And now her whore of a daughter probably knew about the letter theft. Years of planning and finally wooing the woman – all for nothing! Throwing up silencing wards, he let out a scream of rage and threw his glass against the wall. The bitch belonged to him! She had no right to leave! He was going to find both of them and drag them back to England if he had to. He smirked. Though the girl would probably beg her mother to bring her back after discovering her friends had forgotten her due to years without contact. They'd probably be home within a week. After all, what reason did they have to stay?

* * *

After several minutes of assuring her that no, this was not a prank, Cordelia accepted her reasons for not staying in contact and offered to help her and Xander find the thief. At this, Izzy raised an incredulous brow at her friend.

"Are you sure that's such a good idea Cordy? I mean, Xan and Willow _are_ members of the _I Hate Cordelia Club_." she told her sardonically. Cordelia winced. Yeah, she'd become a real bitch after Izzy had left. The charming, level-headed ginger had been the only one to keep her grounded, and once that calming presence was gone, she had reverted back to being a spoiled daddy's girl.

"Izzy –"

"Why, Cordy?" she demanded, a hurt look on her face, "You were always so nice to me."

Cordelia sighed.

"Izzy, you were the only person who ever told me 'no'. You treated me like a normal person, not the daughter of a rich man who could get their parents places."

Izzy snorted.

"Cordy, I'm the last of a wealthy line. After I split my vaults with my mother, I'll still have enough money that I nor my great-grandchildren would ever have to work for a living – and that's without my dowry, which is a lot on its own. I don't need someone else's money. I wanted a friend." she suddenly smirked, "Wait – did you just tell me that you need me around to kick your ass to keep you humble?" she asked, her eyes dancing with amusement. Cordelia opened her mouth to deny the claim, thought over her words, and closed it defeat. In a round about way – that was exactly what she'd said. Laughing delightedly, Izzy roped her arm through Cordelia's, patting the hand resting on her arm.

"Don't worry, Cordy. In a few days everyone will remember me except the new people and your reputation will stay in tact."

Cordelia groaned.

"Somehow I doubt that."

Izzy merely chuckled as they continued on down the hall.

* * *

Later, Izzy found herself alone in the library. While she was there, however, she heard something highly unusual – even for Sunnydale. Sunnydale's newest residence arguing with the new librarian, even though that in and of itself wasn't strange, the argument itself was. So was the book the librarian was pushing at her. It had the word VAMPYR embossed on the front. Izzy felt the blood drain from her face as she listened to the conversation.

"That's not what I'm looking for." she told him in a slightly panicked voice. The man frowned.

"Are you sure?"

"_Way_ sure."

"My mistake."

Izzy didn't wait to hear more. She bolted from the room without bothering to find the book she needed. She would have to talk to the librarian later. Just to ensure that she was only being paranoid.

* * *

Izzy followed Xander and Jesse over to where Willow was talking to the new girl. Xander hopped up on the wall and Jesse walked around to stand in front of them. Izzy walked around the wall and leaned on it. She grinned at Willow and the new girl.

"'Lo, Wills."

Willow smiled

"Hi Izzy!"

She turned back to the blonde beside her.

"Buffy, this is Jesse and that's Xander and his cousin Isabella, but we all call her Izzy."

Xander gave a lazy wave of his hand.

"Oh, me and Buffy go waaay back, old friends, very close. Then there's that period of estrangement where I think we were both growing as people, but now here we are, like old times, I'm quite moved."

Jesse shot his friend an amused look.

"Is it me, or are you turning into a bibbling idiot?"

Izzy chuckled.

"Oh, no, it's not just you. He's turning into a bibbling idiot."

"Well, it's nice to meet you guys, I think."

Izzy snickered.

"Ignore them, Buffy. They're usually not complete idiots – it's just the presence of a pretty girl that isn't family or Willow fries their brains. They'll get used to you eventually."

Buffy was tricked into a laugh – at least until Xander took a stake from his backpack and handed it to Buffy. Izzy paled and quickly made her apologies before making a hasty retreat for the library. She needed to speak with that librarian.

* * *

Making sure the library was empty, Izzy threw up wards and made her way to the desk, where a mild-looking man in tweed and a pair of glasses resting on his nose, sat reading a rather large and dusty tome. He seemed to feel the wards when they went up, because he put down his book down and his head snapped up. His eyes narrowed when he caught sight of her.

"May I help you, young lady?"

She smiled easily at him.

"I'm Isabella Prewett."

His eyes widened and he quickly rounded the desk. He took her outstretched and pressed a kiss to the knuckles. Izzy giggled. She wasn't used to traditional greetings.

"Lady Prewett, Rupert Giles at you service."

Izzy sighed.

"Please, call me Izzy – or any variation of the name Isabella that you prefer, Mr. Giles."

He smiled.

"Then please call me Giles if you do not mind me calling you Bella."

Izzy beamed.

"Not at all!" her smile faded, "Though, unfortunately, I do have a non-library related issue to ask you about."

Giles frowned.

"How can I help?"

"You're a Watcher, aren't you?"

He gaped at her.

"H-how did you –?"

She bit her lip, her expression sheepish.

"I heard you and Buffy speaking earlier. Is she really –?"

Giles sighed and nodded.

"Yes, she is."

Izzy paled.

"I want to help her." she blurted. Giles raised a brow.

"Train. I want to help her train." she clarified. He studied her for a moment, then nodded.

"First you will have to convince her that she cannot "quit" as I have heard she is determined to do."

Her brow furrowed.

"Quit? She can't. This isn't some job that anyone can have – she is literally the only person alive who can do this."

He inclined his head.

"I am aware of that, and you are, but Buffy, I believe, is frightened. She needs encouragement from an outside source."

She nodded.

"I can do that."

With a quick goodbye, she turned on her heel and left, the wards falling behind her. Now, all she had to do was convince Buffy Summers that she couldn't just _stop_ being a Slayer. _Great_, she thought sarcastically. _And while I'm at it, I'll invite Voldemort for tea_.


End file.
