A\N: And the third chapter is here! I have a couple of things to tell you, but you'll find them at the end of this chapter. Thank you for reading! I remind you that English is not my first language, so let me know if you find any mistakes. Reviews are welcolmed with open arms.

Disclaimer: I don't own anything in the Harry Potter universe, it all belongs to J.K. Rowling.

From the previous chapter:

He turned a corner and suddenly saw in front of him something that froze the blood in his veins.

The corridor was slightly dark. A few torches on the wall sketched shaking shadows on the barren stone; there were no paintings. It was the wing were the old Potions Lab was, he absent-mindedly registered; the old Lab that had not been used since the last Potions Mistress decided to move to the Dungeons. That place was abandoned; there were only empty classrooms.

And in the middle of the corridor the girl laid on the floor, motionless and wide-eyed, a cheek on the cold ground. A horrible gash ruined her face, forming a bloody wound on her neck. Her long hair surrounded her head like a halo. Her sweater was ripped in two, and the white shirt below showed an increasing red stain. The blood was everywhere: under her body, on the walls, on the window a few meters away. Vague trails of water could be seen on the floor.

Even as far as he was standing, the Prefect knew with absolute certainty that Katerina's heart was no longer beating.

Katerina's body suddenly gave a start as if stricken by lightning, and she abruptly got up. Her hand rose to touch the lacerate skin on her left cheek, and she began to shiver. Her breathing was labored and she violently coughed a few times. Her disheveled dark hair, dirtied by dust and blood, covered her thin shoulders; she looked horrible, as if she was the only survivor of a catastrophic accident. She seemed a frail, broken porcelain doll, much younger than she actually was.

Slowly, from her throat came a chilling lament, while she covered her head with her hands to protect herself. She looked like an animal caught in a trap and severely injured.

The Prefect watched her shake and whisper something that sounded like "no, no, no…". He sighed wearily: it would be a long night.

He felt simply furious, and incredulous. It wasn't supposed to go that way, it wasn't the conclusion he had predicted. She was not supposed to be there, in that moment and in that state, injured and scared. It wasn't right, not for her and especially not for him. He had done his best to make sure that things wouldn't take a bad turn, and yet here they were. He failed, and the fault lay in some stupid and unpredictable external forces. He wanted so badly to break something. But it would not help him; after all, he was about to start a conversation that was not easy to make, nor to hear. Breaking things wouldn't help make it taste less bitter. He remembered very well that time he had been in her place.

He couldn't say if he was angrier at the girl – because come on, no one could possibly be as unlucky as she had been – or at whomever had her in that mess.

"Hey," he curtly said, just to let her know he was behind her.

If possible, Katerina jumped even more violently than before. She turned towards him with a scared look on her face. She cautiously slid her legs to sit properly upon the desk she was on, one of the tables left inside the old Potions Lab. After seeing her, the Prefect couldn't help wincing slightly. Her face, usually smooth and round, was in terrible conditions. He leaned with his back against the wall and crossed his arms, waiting for her to stop looking around and assessing the situation.

"Who are you?", she asked at last. "What - what happened to me?"

"My name is Louis. I am in Slytherin. Sixth-year, and Prefect. Never seen me around?", he shortly said. The girl had a calculating look in her eyes. He couldn't say if she knew him or not, and she didn't answer. He kept looking at her for another brief moment: he had tried to remove some blood from her face, and it hadn't been enough.

"As for what happened to you, I'll tell you in a moment. We have a long conversation ahead."

"Why are my hands covered in blood?", she suddenly asked. "And why…" one of her hands touched again the rugged injury on her cheek and neck. "… oh no. No," she panted breathlessly. She started to struggle to get down the desk.

"Wait, wait! Be quiet. Your wounds don't matter now, they won't hurt you. Do you feel pain?", he quickly asked.

The girl slowly shook her head in trembling negation. Now she was looking at him wide-eyed, full of expectation. While he was waiting for her to wake up he had decided what to tell her, and how to tell her. He had tried to be calm and reassuring, because the situation was really delicate.

Well, now he didn't remember a word. What to say?

"There's been an attack," he finally said. She kept watching him, frowning.

"The Syndrome again?", she whispered.

The Syndrome? That sickness was certainly disturbing, but he wondered why she had associated it with the word attack.

"I don't know. It's a possibility," he admitted. "But this time the victim died."

"What?", she panted. "Who's dead?"

"Well, you."

The girl made a face that suggested he had grown another head or something. Louis sighed. It would be a really, really long night.

Katerina felt forced to point out the obvious.

"You are wrong. I'm not dead. I wouldn't be here talking to you, if I were," she said slowly, to make sure he would grasp the meaning of her words and understand his mistake. Of course, she silently told herself, I don't know where I am and what happened to half of my face, but I am surely not dead. He was probably joking, but she didn't find him funny at all: after all she had just woken up in a unknown classroom, without memories of how she had gotten there and completely covered in blood.

It was unreal; she must be trapped in a some kind of strange nightmare. She felt confused and terrified. The worst part was that she knew that the blood covering her hands and face was hers. She wanted to Evoke a mirror to see in what state was her face, but she didn't feel brave enough to actually do it. And why the hell did her wounds not hurt?

"Look," Louis started again with a slightly bored tone. "It won't be easy to understand what I am about to say, so please focus."

He moved away from the wall and sat on a chair, looking straight at her.

She watched him closely. At first she hadn't been able to remember where she had seen him before, but after his introduction she did. She knew him only by sight, however. He was tall, thin, with dark blond curly hair, and he was the Slytherin Prefect that had once deducted points to Abigail because she had crossed the corridor in front of him. What was his surname?

"Just tell me what happened to me, and what I am doing here," she said. All that fear was starting to make her feel annoyed. Couldn't he just tell her what was wrong?

"Alright, if you insist. That's the shortest part of our story. The last time I saw you alive, you were sleeping in the Library. I got lost in my thoughts, and when I looked again you weren't there anymore. So I went out the Library and began to look for you. I thought you were simply tired, and wanted to go back to your Common Room."

"That's right," she weakly confirmed, moving her legs again. They ached as if she had run a marathon. For a brief moment her head started to spin, and the room became darker. It was nearly empty – just a few desks and chairs all covered in dust. There was also a broken blackboard, with a few notes still written on it. All in all, it seemed no one had entered that classroom for a very long time. She tried to focus and frowned. It was right, she did fall asleep in the Library; then she had woken up with a start and a great pain in the neck, and decided to call it a night. Something of what the boy had just said sounded wrong, however. "But why…?"

"Why I was following you? I'll explain later," he curtly interrupted. "That's the most interesting part, by the way. So, I started to walk towards the Ravenclaw Tower. I found you in a corridor on the third floor, just outside the abandoned Potions quarters, that is where we are now. I hope you are aware that this place is not anywhere near your Common Room. What the hell were you doing here?", he asked. He almost sounded angry.

"I don't know," she answered defensively. Third floor? Abandoned quarters? She had no idea why she was there. And she didn't trust that boy at all: he had just told her that she was dead, for Merlin's sake. Or was it a threat?

"How can you not know?", he asked, then shrugged his shoulders. "Anyway, when I found you, you were in a very bad state. You were on the ground, covered in blood, and you were dead. I suppose someone or something attacked you. What was it? I had never seen wounds like that before."

Katerina, wordless, shook her head. Her mind kept to be blank. She couldn't grasp the meaning of what Louis was telling her; it felt like they were talking about someone else.

"Mh. In any case, I brought you inside this room and fixed the mess outside. And now, three hours later, here we are. Hope you enjoyed the story of how you died."

"Three hours?", she uttered. She felt the irresistible need to look at her wrist watch: it was true, it was past midnight. After a second thought she checked again: it didn't seem someone had tampered with it, and anyway, why would one do that? And now she had a hole of three hours that she couldn't explain. While she was furiously thinking, the words came out from her mouth on their own.

"You said you went towards the Tower to see where I was. Then how did you manage to find me, if we are so far from it? I seriously doubt you searched the whole castle. And anyway why were you looking for me? I don't even know you."

Louis stared at her for a while, looking puzzled.

"I just told you I found your dead body in the middle of a corridor, and that is what struck you the most?" His tone was genuinely perplexed. "You don't hear things like this every day. I admit I thought you would be more impressed. Or are you trying to find a loophole because you think it's all a lie? It's not, you know. You really died. And for the record, I'm not the one who killed you."

"Yes, well, you didn't answer my question."

"Alright, alright. The answer is: no, I did not search the whole castle. I didn't need that, because yesterday I cast a Locating Spell on you."

Katerina shivered from a thick pang of fear.

"What? Why did you do that?"

"Because I wanted to know where you were, obviously," said Louis raising a eyebrow.

This was too much. Katerina slid down from the desk and got up on her feet, looking at Louis with hostility.

"Listen, I don't know what you want from me, but I won't stay here any longer. You are clearly mad as a hatter, so please just leave me alone," she said sharply.

She strode towards the door. She was about to grab the door handle, but before her hand had reached its destination she was violently thrown in the middle of the room. She fell on the floor, hurting her back. Suddenly something terrifying stood between her and the door.

It was Louis, but at the same time it wasn't.

His eyes were red and blood-shot. The veins on his face were more visible than ever. From his throat came a low menacing growl, and his mouth showed unnaturally sharp-pointed teeth.

He stared at her. Katerina stood still, paralyzed on the floor by fear and surprise, and looked back at him, gaping. She could not move. She stopped breathing, and waited for the aggression that was about to come, for the feeling of those teeth biting her neck.

As suddenly as it had appeared, the monster went away, leaving only an ominous red glimmer in Louis' eyes.

"Not so fast," he hoarsely said. "We have a couple of things to discuss. Moreover, it's not safe to go around without this."

He calmly drew her wand from his pocket, and casually started to play with it.

"What are you?", stuttered Katerina as soon as she felt capable to talk again. Louis smiled bitterly.

"I am the same as you," he answered, and then raised an eyebrow. "I am a vampire."

The girl's reaction, he had to admit, was priceless.

The expression on her face, a mix of fear and worry, became pure and unlimited horror.

That girl, Louis thought while he was waiting for her to overcome her shock, seemed a bit insane. Something inside her head made her shift without notice from a weak to an aggressive attitude, and vice versa. Like now, for example: in a half a second she wasn't a scared little puppy anymore, but stood up with an extremely serious expression on her pale face.

"When you say vampire," she started slowly, "you realize you don't make any sense, right? I would have noticed if I were a vampire. As for you, I don't know what's wrong with you, but if there ever was a vampire at Hogwarts he surely would not be still alive to tell the story. Therefore," she concluded, "I really don't – excuse me, does it amuse you?"

Hearing her speak, Louis had begun to smile broadly.

"Not at all," he said. He kept on smiling because he knew it unnerved her. "I just feel extremely pleased: I never realized how good I am at escaping the vampire police. Listen," he added in a more serious tone, before she could interrupt him, "I know it's hard to believe, but there are a few things I need to tell you, and then you might find everything clearer. You won't go away from here any time soon. By the way, I thought it would be obvious, but clearly it is not, so let me explain: the door is spell-locked and your wand is in my hand, so, you see, you don't really have a choice. Now sit."

He watched her give up her rebel attitude and slowly sit on the same desk as before. She turned away from him and lowered her eyes to stare at her blood-stained hands. There was a moment of silence.

"It doesn't make sense," Katerina repeated, quickly glancing at the boy in front of her. "Vampires are Dark creatures. They are soulless and bloodthirsty monsters. Everyone knows that. You say you are a vampire, but you look… normal. More or less. If you don't consider what happened a few minutes ago."

"Thank you," he rolled his eyes. "Truth is, what everyone knows, as you say, is false or at least misunderstood."

"What do you mean?"

"Wake up, Katerina," he calmly said. "Wizards and witches aren't exactly famous for holding dear their magical minorities. Elves, mermaids, werewolves, vampires - to say that they are seen as subprime citizens is an understatement. Rules have been made, but the truth is that they don't want those minorities to be part of the wizarding world; they'd rather have them as far away as possible. No one was ever interested in trying to understand the real nature of these people. Just think about all the prejudices against the Muggleborns, and they are exactly as human as the Purebloods."

"Are you saying that all we know about vampires is just unfounded rumours?", she asked, skeptical. In spite of everything, her Ravenclaw spirit found that idea quite interesting.

"Not quite," he admitted. "What I am saying is that we are soulless and bloodthirsty monsters, as you kindly described us. Well, not really soulless, even if sometimes we feel a little bit like that. What I want you to understand is that wizards don't really know anything about vampires. They are afraid of us, and their fear caused wars and death all over the centuries. Hence vampires prefer to live far from them, to stay in the shadows and never reveal themselves. Just like the wizards had to hide from the Muggles before the Statute of Secrecy."

"You make it sound like the vampires are the victims. But vampires are cruel, and have to kill people to survive; there was a reason for all the fear and the fighting," she retorted, then closed her mouth. A quick thought made her realize that maybe it wasn't a good idea to anger him. Anyway, he just shrugged.

"No one is ever completely a victim," he simply said.

"But you don't stay in the shadows. You live in a school full of people," she calmly observed, recalling what he had just said.

"I do. I managed to keep going to school because I took advantage of all the preconceptions. No one ever realized what I am because no one really knows how to recognize a vampire. To the untrained eye, I am just another one of the hundreds of students living here. You should be grateful, because from now on you'll have to hide in the crowd too."

Ignoring his last sentence, she mused, "I can't believe no one ever studied vampires. We've had a great number of researchers over the centuries; at least one of them must have studied Dark creatures. For example Newt Scamander is known for…"

"Someone probably did, but it was not enough – just another voice in the chorus," he interrupted her.

"But we've been taught this things at school. We studied vampires in our third year."

"And as you are a Ravenclaw, discovering that school teaches something wrong horrifies you. I understand. I'm sorry, but it's the hard truth."

His tone was jokingly solemn, and she let out an unsure half-laugh. His posture seemed more relaxed, now that they were speaking calmly. His grey eyes had some kind of twinkle that had nothing to do with the menacing red glimmer she saw before.

"Come on, tell me what you think you know," he said crossing his arms.

"Well, actually - it's what I said before." She hesitated. "Vampires are Dark semi-human creatures. Undead beings. They need to drink human blood in order to survive, and they often kill the victim they feed on. They have some sort of mental power, which they use to bewitch people. Garlic repels them, wooden stakes kill them."

Louis nodded, then raised his fingers as if he was counting.

"Well, you got almost right the feeding and killing part. We are actually dead, it's true. We don't really have to drink blood to survive, because we can't starve to death, but I assure you don't want to meet a hungry vampire. The curse on us is so powerful that we can never die, unless we are staked directly in the heart by something made of wood, or beheaded. We don't age, we don't get sick. It is said that thousand-years old vampires still live somewhere in the world."

Katerina couldn't stop staring at him. It was fascinating.

"We don't always kill our victims; some of us do, others don't. It's up to personal taste, I suppose. Finally, garlic is completely useless, even if it's funny to make people believe the opposite. No, what really is toxic is vervain; you know, a plant."

"How do you become a vampire? Do you have to be born one?", asked Katerina curiously.

"No, you don't have to be born." He stopped for a moment and stared at her as if he was wondering something. Then he started talking again. "There is only one way to become a vampire: you have to die shortly after ingesting the blood of another vampire."

Katerina seemed to ponder his last sentence, while inside her head some alarm bells were probably starting to ring. Louis watched her put two and two together.

"So I – you told me that now I am a vampire. You told me I died – and I think I believe you, even if it sounds crazy," she sharply said. "When did I ever drink the blood of a vampire? Why should I have done something like that?" She frowned. "Why were you following me tonight?"

Louis was sure she wouldn't take the truth very well.

"Katerina, I've been following you for a week. I saw you in the Library a while ago and I realized you were always alone. You stayed there for hours, studying on your own, sometimes even after curfew. I took some time to be sure, but then I decided that no one would have noticed if you went missing for a while."

She was agape, her breath faster and faster.

"What did you do to me?" she whispered, horrified.

"Last night I waited until the Library was empty. I had cast a Lessening Spell to make sure no one would bother you, and that you wouldn't realize how late it was. I Stunned, Disillusioned and Levitated you in a safer place."

Katerina was as pale as a ghost.

"You – you fed on me?", she uttered, her voice higher than usual. She took a few steps backwards, to distance herself from him. Louis shrugged.

"You were the perfect victim. It was nothing personal; if it weren't you, it would have been someone else."

"But I can't remember any of this!", she yelled, putting a hand on her head. She looked about to break down and cry. "I woke up in an empty classroom, covered in blood – you tell me I'm dead, that I became a vampire and – and are you telling me I was attacked two nights in a row by two different people?" She put her hands on her hips, watching him angrily. "I seriously doubt that. No one could ever be that unlucky. It was you both times."

"It wasn't me," Louis sighed. "But you have a point. It's absurd how unlucky you are."

"I don't believe you," she hissed, while tears started streaming down her cheeks. She strode towards the door, passing beside him. "Why should I trust the word of a vampire? Let me out!"

"You are not going anywhere," he firmly retorted.

Katerina looked at him, her face full of hate. Suddenly she raised her fists and started to hit him on his chest.

"Let – me – out!"

Hitting him again, she reached out one of her hands to grab her wand in his pocket, but Louis caught her wrist.

"Stop! What the hell are you doing?!"

The girl tried to hit him in the face with the other hand, but he caught that too. Now both her wrists were trapped in his hands, but she uselessly kept struggling to free herself.

"Stop!" He violently shook her, and she seemed to freeze. He lowered his head to angrily look in her dark eyes.

"Now listen to me, you insane, lunatic fool. You can get mad as much as you want, but that's what happened. I didn't lie to you. I attacked you the first night, but not the second. Yes, I drank your blood. You don't remember anything because you were Stunned most of the time, and when you woke up I changed your memories in order to make you forget me. I don't care if you are too prude to understand, but we'll see what you do when the thirst will have you jump at the jugular of the first poor bastard you meet."

He venomously shook her again and then freed her. She immediately made a step backwards, contempt in her eyes.

"If you only drank my blood, why did I ingest yours?", she asked angrily. Louis crossed his arms.

"The blood of a vampire has highly healing properties. It has to, because the immortality spell is cast upon it, hence it can rapidly heal us when we need it. I knew I couldn't just send you back with those injuries on the neck and less blood than you should have had, so I gave you some drops of my blood to heal you. But damn, I should not have done that." He kicked the nearest chair and it broke. "Vampiric blood stays in your system for twenty-four to forty-eight hours at the most, so I simply decided to keep an eye on you to make sure you wouldn't have yourself killed and become a vampire. You weren't the first, you know; I did it more than once. I was so sure you would be fine – you don't often hear about dead students at Hogwarts, after all," he bitterly said. Now he felt the same fury as before, when he had found Katerina dead on the floor. "But no, in five minutes' time you managed to go away on your own and have yourself murdered. It wasn't supposed to go like that!"

Katerina opened her eyes widely.

"Now it's my fault?", she shouted. "What do I have to do with you being a lousy bodyguard? I didn't ask you to attack me. I did nothing to you – we never even spoke to each other! You could just leave me alone, and none of this would have happened!"

"Oh I don't think so. You should thank me, to be honest! I wasn't the one who killed you, remember? If I hadn't given you my blood you would have died and never come back to life, so there. You wouldn't be here yelling and shouting, you would just be dead. Much a smaller problem, if you ask me," he concluded in a hateful tone.

"Just let me out and I won't be your problem anymore," she gelidly retorted.

"Yeah, right. Don't be silly. If they find out about you, they'll find out about me too. Maybe wizards don't know us very well, but they are perfectly capable to put two and two together, should someone attack them for their blood. I'm not going to be caught because of you, so now calm down and think." He grabbed her arm and lowered his voice. "I know it's hard to accept, but this is what you are now. You can deny it and die now, or you can survive."

Katerina stood there, unmoving.

"I don't want to die," she reluctantly whispered after a few seconds.

"Then listen to me. No one, and I say no one, will have to know what you have become. They wouldn't understand, Katerina. They'd kill you without thinking twice. You'll have to be careful, whatever you do. Promise me." The girl didn't say anything. "Promise me you won't put us in danger."

"I promise," she slowly said.

"Good. Now drink this," he told her, Evoking a closed red phial. He handed it out to her. Katerina took it and opened it. Its content was a dark red liquid that tickled her nostrils.

"Is it what I think it is? Blood?"

"Of course."

"Whose is it?"

"You don't need to know. Now think about it, Katerina. You are now in a transient state between human and vampire: this is why your wounds haven't healed yet. You are nor the one nor the other. If you drink this blood you'll complete your transformation and become a vampire; if you don't, you'll die for good in a few hours. The choice is yours."

"Why are you telling me this just now?"

"It wasn't important," he frowned. Katerina watched him closely.

"Maybe you thought you could just keep the blood for yourself and let me die, if I were a threat to your secret," she accused him.

"Even if you drink it now, don't you ever think I wouldn't be able to kill you," he answered raising his eyebrow. But he didn't deny.

Katerina didn't say anything to that. She kept the phial in her hand as if it was a bomb about to explode. She stared at it with caution and fear. Finally she began to raise it towards her mouth, but then hesitated, and lowered it down.

A\N part 2: so yes, this is a story about vampires. I'll try my best to keep them consistent with the Harry Potter universe, but I think they fit in rather well. You may have read something that sounds familiar: I imagined a few things on my own, but I borrowed something from multiple sources, mainly The Vampire Diaries. You don't need to know anything about it because I'll explain everything in the story - well, I mostly already have.

The protagonist's name, Katerina, is a nod to one of the characters in The Vampire Diaries, namely Katherine Pierce. They have nothing in common save the name. Furthermore, Louis owes his name to Louis de Pointe du Lac, a character in Anne Rice's The Vampire Chronicles.