Author's Note: I have no claim over Buffy and Co., nor over Harry and crew. They belong to Joss Whedon and JK Rowling, respectively. Please read and review!

Winter holiday had finally come and most of the students prepared to go home. A handful of students remained, including Harry, Ron and Hermione. Ron's family was going to visit Charlie in Romania and Hermione had convinced her parents she needed to study for exams. Despite the lack of students, Hogwarts hummed with an air of excitement. However, no one was more excited than Buffy.

It took her a moment to realize what it was she felt. She hadn't been excited by anything in a very long time and it showed during her training session with Snape. She almost sliced off his head with the sword she used for practice. His arms windmilled and the sword flew out of his hands and clanged loudly on the floor.

"Oh my god! I am so sorry! Are you ok?" She rushed to his side. His hand clutched his throat, feeling for any sign of a wound. Severus looked into her wide, fearful eyes and almost laughed at her worried expression.

"No, I'm fine. I suppose that's what I get for working with the slayer. I must say though, I've never seen you quite so…zealous. Any particular reason for your exuberance?"

"Didn't I tell you? My sister Dawn is coming to visit over Christmas break. She's coming tomorrow!"

"No you didn't mention that actually. How long is she going to be here?" He suddenly seemed apprehensive, and busied himself with tidying the weapons. Buffy, too far in her own delight, failed to notice the change in Severus' demeanor.

"She'll be here for most of the holiday. I think she's going back home a day or two before the students come back. I'm so glad she was able to talk dad into letting her come. He doesn't really know exactly where I am or what I'm doing here so I was afraid he'd start asking awkward questions." She continued to babble as they left the training dungeon.

Severus listened and nodded with more patience than he showed most people, but he felt troubled. Her sister was visiting? He'd never met Buffy's family, except in her own memories. How much had she told Dawn about him? What would she think about him? He couldn't imagine that she would like him or his relationship with Buffy. He was suddenly very nervous, but as he listened to Buffy ramble, he felt reluctant to dampen her spirits, particularly since this was the happiest he had ever seen her.

They reached Buffy's room where she stopped talking for a moment to look at him.

"I promise you'll like her Severus. She's not like the rest of the 'mush heads' you have to teach here. She gets her wise-ass-ness from me, probably, but she's really smart and dedicated. She'll make a really good watcher some day and some slayer is going to be very lucky to have her."

"I'll be waiting with bated breath," he said with conviction he didn't really feel. Buffy smiled at him. "Well, I should get to bed. I have to be at Diagon Alley in the morning to meet Dawn at the Leaky Cauldron. Hagrid's going to meet her at the airport and they're going to portkey here," she said. She gave him a quick kiss and another smile and entered her room.

Severus turned to go to the dungeons, his face melting into its usual hateful mask. There was an uncomfortable feeling bubbling in the pit of his stomach, which puzzled him until he realized what it was; fear. He could scarcely believe that he, who had been lying to and spying on the Dark Lord for many months, could be afraid of a teenager. But there it was, the almost paralyzing uncertainty and sense of no escape. Tomorrow he'd be meeting "the family."

Buffy woke early, but not because of the nightmares this time. She sped through her morning routine and was ready to go far earlier than her scheduled appointment with Dumbledore. He had set up a portkey to Diagon Alley and another one to bring them back. She whittled some stakes until she'd gotten so many splinters she realized she couldn't concentrate.

Dumbledore was waiting for her when she reached his office. "Ah, Buffy, there you are," he said, his eyes twinkling. "I'm surprised you didn't arrive fifteen minutes earlier." Buffy had the temerity to blush.

"Well, I was ready to go about an hour ago, but Giles used to say that ninety percent of the slaying game was waiting. Believe it or not I have learned some patience." Dumbledore just chuckled. He moved to his desk and picked up and old penny loafer and handed it to her.

"Hagrid's already gone to Heathrow to meet Dawn and he'll portkey to the Leaky Cauldron to meet you at 10:30. It's 10:00 now and your key is set to activate in five minutes. Hagrid has the return portkey set for 4:00. I figured you'd like some time to show Dawn around Diagon Alley. Her familiarity with magic should make it an educational trip. Do you have any questions?"

"Do the students and staff know that Dawn's coming?"

"The staff is aware, I believe, although the students have not been informed. I don't imagine there will be any trouble explaining her presence. If I'm not mistaken, your portkey should go in three…two…one." As the last syllable passed Dumbledore's lips, Buffy felt herself pulled in some aimless direction. She crashed into the ground when she stopped.

"I think I'd rather apparate," she muttered, as she tried to look like she'd meant to lose her balance. As far as she could tell, she was in one of the vacant rooms at the Leaky Cauldron. Through the window she could see cloaked people strolling in the street below. She went downstairs where a gap-toothed bartender was wiping down glasses.

"'Ello there miss! You must be Buffy. Dumbledore said you'd be comin' in today. Pickin' up your sister, eh?" Buffy nodded. "Well, Hagrid ain't been through yet. Can I get you somethin' while you wait?"

"No thanks, I'll wait till Dawn gets here." Tom nodded and turned his attention back to the glass in his hand. Buffy had been sitting for about five minutes when Hagrid's large form suddenly filled the room, and she heard the terrorized squeak from somewhere behind the folds of his coat. Hagrid twisted and turned as Dawn fought her way to the front. She squealed again as she saw Buffy and bolted into her sister's arms. They hugged silently for several moments and there were tears on both of their faces when they broke apart. "Tom, I think we could use a couple of Butterbeers now," Buffy said, without taking her eyes from Dawn.

They spent the rest of the afternoon browsing the goods that Diagon Alley had to offer. They spent a great deal of time in Zonko's Joke Shop and Honeydukes, where Dawn picked up various gags and candies for the remaining Scoobies. She even bought some blood lollipops for Spike.

"Hey, just because you two don't talk anymore doesn't mean that I can't," Dawn said, defending her would-be older brother. They rounded off the afternoon back at the Leaky Cauldron for another Butterbeer before heading back to the castle for dinner. "You're never going to believe Hogwarts, Dawnie. Sunnydale had some crazy stuff, but you've never seen anything like this." Hagrid, who, until this time, had been following at a discrete distance, now came forward.

"An' speakin' of Hogwarts, it's almost 4:30 so we should be getting' back."

"Of course Hagrid. Time flies when you're having fun," Buffy said, smiling at Dawn.

They portkeyed back to the castle where Dawn's eyes nearly popped out of her skull.

"You've lived here for the past several months and never sent me so much as a picture? You are so dead!" Tiny fists of rage pelted Buffy's shoulder. Hagrid assured them that Dawn's luggage would end up in Buffy's room so she was free to take Dawn to dinner. Her eyes bulged further as they entered the great hall.

"Look," Buffy pointed at the ceiling. "It's enchanted to look like the sky outside." Dawn's jaw worked up and down like a fish out of water. Buffy poked her in jest. "If you're not careful something's going to fly in there." She steered Dawn toward to Gryffindor table where Harry sat with Ron and Hermione, and a few other remaining housemates. "Guys, I'd like you to meet my sister Dawn. Dawn, this is Harry Potter and his friends Ron Weasley and Hermione Granger. They're what you might call Hogwarts' answer to the Scooby Gang." Comprehension bloomed on Dawn's face as the got the private joke and she laughed. The others exchanged confused looks. They chatted congenially, discussing the differences in magical education between England and the States.

"So what do you think Dawn? What's different about practicing magic here versus California?" Harry asked. Buffy glanced at her sister apprehensively. Fortunately, Dawn wasn't stupid.

"Well, I haven't even been here for twenty four hours yet, so I can't really compare. But I can tell you from experience that the magic in California can really keep you on your toes. It seems like I learn something new every day." Her answer, though a little cryptic, seemed to satisfy the trio. Dawn also stealthily changed the subject. "So Buffy, is it me or is that one teaching making with the scowling at you?" She followed Dawn's gaze to the head table.

"Oh, that's Professor Snape. Don't worry, he looks like that all the time. You'll get a chance to meet him later along with the rest of the teachers." After dinner Buffy took Dawn on a tour of the castle, in all its labyrinthian glory. "You'll probably want to stick with me or Harry or his friends if you're wandering around the castle. Things have a way of moving around here and it's real easy to get lost. I learned that the hard way. There's nothing quite like panicking at two in the morning because you can't find your way back to your room," Buffy said. Suddenly a wet raspberry erupted from above their heads as Peeves materialized. "Especially with this bastard floating around. Go away Peeves, or I'll call the Bloody Baron." He sputtered again and popped out of sight.

"Poltergeist?" asked Dawn. Buffy nodded. The tour ended in the dungeon Dumbledore had equipped for her training room. "You've gotta check this out. This set up is better than the Magic Box, but don't tell Giles I said that." Buffy started showcasing her fancy new weapons.

"So what's up with the Crank Monster from dinner? He looked about as friendly as an uber-vamp on a bad day," Dawn said as she played with some throwing knives.

"Severus?" asked Buffy.

"Ooh, on a first name basis are we?" Buffy rolled her eyes.

"Anyway, Severus just has a lot to deal with. There's stuff going down here and he's stuck with the role of the double agent. Needless to say it's a lot of stress."

"Well, that makes sense. You do have a history of going for the ones with the trauma," Dawn said wickedly. Buffy's head snapped up, her mouth agape. "What, you think I couldn't tell? Please, it's written all over your face. You wanna tell me what happened or are you going to make me invent fantastical stories that are inevitably worse than reality?"

"Brat! Well, it all started with these awful things called Dementors…"