notes: Thanks Apachep for your positive feedback. It encouraged me to write another chapter. :)

Chapter 4

Back in Dumbledore's office the atmosphere was chilly despite the warmth from the fire. "What was that?" Harry demanded, all politeness forgotten with his desire to know more.

"Harry, please take a seat. I'll tell you everything."

"I'd prefer to stand," Harry stated as he crossed his arms over his chest and waited for the explanations to begin.

Dumbledore sighed and moved to take his own seat behind the desk. "You'll have to excuse me for taking my own suggestion. I'm old you know. Now please, no questions until I'm done. It will be easier that way." After he was sufficiently settled, the story of Ava Potter began, what little he knew of it. "Before your parents even knew that your mother was pregnant they received a visit from the two men you saw in the memory. Jonah and Malcolm, I believe was the older man's name. They explained to your parents that your mother was carrying the possible future of the vampire slayer line… a girl. Vampire slayers are always girls so there could be no doubt. The two men were from an organization that was known as the Watcher's Council. Somehow, they have the ability to locate future vampire slayers, 'potentials' is what they call them. I don't know exactly how they do it as the council is very secretive about what goes on in their world just as we go to such great lengths to keep our world hidden from muggles. I suspect that since vampire slayer potentials inherit so much power that they must emit some kind of magical energy as soon as they come into existence and the council is usually able to locate them that way. Of course, your parents were quite taken aback by this revelation since they didn't even know they were expecting a baby and they were curious to hear these men out. Jonah and Malcolm told your parents that a long time ago, before there was wizards and witches, many evil beings roamed the earth and made humans into their prey. A group of very strong men used a powerful magic very different from ours to create a champion for the humans… one girl with the strength to take on and defeat that evils of the world, the vampire slayer. Unfortunately, they only had enough magic in them to generate enough power for one girl so they had to make sure it didn't die with her. As one slayer dies, the next one is called, usually in her early or mid-teen years and when she dies, the next one is called and so on, do you understand?"

"Yes," Harry finally sank into the chair behind him. "But if they don't get their powers until they are teenagers, why did they come take Ava away as soon she was born?"

"That's a good question. When those men created they slayer, they also became her teachers. Just because she has supernatural abilities doesn't mean the slayer automatically knows how to use them. She needs a guide to train her to harness her powers so she can fight the most effectively, watch over her and also, to explain the heritage of the line so she can understand what she is fighting for and maybe to learn from past slayer's mistakes. A 'watcher', if you will. Malcolm, had been a watcher for many years and then he became a teacher of future watchers. Jonah was his apprentice and Ava was the potential slayer that Jonah was to protect and train in the event that the slayer line was passed on to her. The watcher's council had decided that the earlier in life that they acquired a potential, the longer that potential had to learn and hopefully that knowledge would give them a chance for a longer life as the slayer. They explained all this to your parents and also how they had to take potential slayers away from their families as the powerful energy of the slayer tends to draw vampires and other evil entities towards it. James and Lily understood that as long as they kept Ava away from her calling that they would be putting her, themselves and any other children they had in constant danger. Jonah and Malcolm left and said they would give your parents a month to think about this information and then they would return. At first, your parents thought they could handle it, they were wizards after all, capable of defending themselves, but when they found out they weren't just having one baby, but two, they decided that it would be selfish of them to risk your life along with theirs and that Ava should go into the capable hands of the watchers. It was a heartbreaking decision for both of them, as you saw, and your parents decided they needed my help. One evening, when your mother was very near her due date, they called me to their house for dinner and explained everything to me. I wasn't completely unaware of the existence of such a creature as the slayer, there were rumors. Even now, there are rumors. In fact, I believe you covered vampires in your third year here at Hogwarts and your DADA book mentioned a possible "society" dedicated to the disposal of vampires, am I correct?"

Harry managed to look somewhat sheepish, "I don't remember, professor."

Dumbledore gave a half-smile, "Well, I'm sure Miss Granger will and she can happily fill you in. In any case, your parents called to ask a favor of me. They wanted me to erase the knowledge of their daughter from their memories. They thought it would be unfair to you for them to bring that kind of melancholy into your home, especially when it would do them no good to worry about her every day. One thing that Malcolm and Jonah had been sure to tell your parents was that if a potential managed to reach her 18th birthday without being called, then she would no longer be in line to become a slayer and the Watcher's Council would release her with the knowledge of where her family was. So, I used a spell that I could easily undo and I took the picture of all four of you together so I would have it in case your parents were to ever get their daughter back." He pulled an envelope simply labeled "The Potters" out of his robes and handed it to Harry who opened it with slightly shaking hands. Inside was the picture he had seen the younger Dumbledore take of his complete family. His mother and father managing to look happy and sad at the same time, himself fast asleep and his sister with her eyes wide open and little arms twitching inside the yellow blanket. Every once in a while his parents would look down at their children lovingly and then look back at the camera.

"But I'm only 16, why are you telling me this now? She couldn't have been released yet. She's only 16 too," he added more for his own benefit as his tired brain tried to process all the overwhelming information it had just been given. "Has she been called?" Harry's head snapped up with his next thought and his face paled, "Has she been killed?"

"No, Harry, she's very much alive," Dumbledore was quick to reassure him. Harry had endured enough loss in his short life, it would have been cruel to tell him that he had had a sister only to let him know that she had died. "But she has been called. In fact, a very interesting thing has happened. You see, someone figured out that just because the original men who created the slayer only had enough magic for there to be one, that didn't mean that there wasn't enough magic in the world now for the rules to change. From now on, every potential will skip the potential part and be born with their slayer powers already in place. They have effectively created a small slayer army all around the world. Now that there will no longer be just one I think the fight against evil will be leaning heavily in favor of the good. Your sister will more than likely still fight, after all, it's what she was brought up to do. However, I believe she will now have the freedom to pick and choose her own battles and I've invited her here to help our cause. And to meet the only family she has left."

Harry looked incredulously at the older man, "My sister is going to slay Lord Voldemort?"

"Well, I don't know about that. But I think she could definitely help us out and Hogwarts could help her out as well. Your sister is a witch as well as a slayer and I think it's time she learned that side of herself."

"So, she's coming here?" Harry asked. "When?"

"I sent Kingsley to track her down a week ago and he's finally located her. He informed me that they should be arriving late tonight. I must tell you Harry, that even though I know Ava will be physically stronger than anyone you've ever met, including Hagrid, I don't know how she's holding up mentally and emotionally. You see, there is much more to the story of how and why all the potentials received their slayer powers at once and unfortunately, it involved some very dark magic and many tragic deaths but I don't think it's necessary at this very moment to tell you about it. It's late and you need to be getting back to your tower. I'm sure Miss Granger and Mr. Weasley are dying of curiosity. I know you will not be able to keep such a thing from them but I must tell you that for now, your sister's true identity, including her relationship to you. must remain a secret."

Harry could barely keep the excitement out of his voice, "I understand but when do I get to meet her?"

"You will meet her tomorrow. She and I will be having a lengthy chat tonight. I already have plans for her fitting in here at Hogwarts and they need to be implemented but after we get everything sorted out, I will send you an owl. I'm sure she will be just as anxious to meet you."

Harry checked his watch and got to his feet. He hadn't realized how long he had been there. It was almost 10:00 and he knew Hermione and Ron would be in the common waiting for him while the other Gryffindors slowly drifted off to their beds.

Dumbledore stopped him, "I have something for you to give to Miss Granger that I'm sure she will find interesting." He pulled a leather-bound book out of a drawer in his desk. Harry took it from him as he bid his headmaster good night but it wasn't until he was bag in the dimly lit hallways of the castle that he bothered to take a closer look at it. The brown leather cover was blank but inside on the first page was written in black ink, 'The Journal of Watcher Rupert Giles, Volume One.'