Disclaimer:I do not own Twilight or Harry Potter. I just use the characters to do my bidding.

Chapter 1

2nd Week of September, Monday Morning

Hogwarts, Potions

It would have been a normal day at Hogwarts, if it hadn't been for the fact that Professor Severus Snape, who took off points on all students (except for those in Slytherin) had come to class even a minute late, had yet to show up for his fifth year class full of Gryffindor's and Slytherin's. It was even more abnormal when a woman (who came through a secret passage in the potions master's office – though no one would ever know that) opened the door to the classroom, 10 minutes after the class was scheduled to begin.

The class was shocked when the woman, who was wearing a muggle shirt telling them 'I don't have a drinking problem, I'm just really thirsty', opened the door to let them in. Her dark hair was bunched up in a messy bun on top of her head, her eyes were the colour of coal, and a scary smile covered her face, "Hello children," she laughed, scaring the (mostly) 15 year olds. Her personality shifted quickly, her smile becoming more sincere and less frightening, her hair slowly changed colour into a teal blue and her eyes turned into an interesting shade of purple. "My name is Bella, and Professor Snape is currently uh… indisposed. So while he is busy doing whatever he is doing, I have come to look after you all. Are there any questions?"

The whole class put their hand up, some even starting their question as if it would get their question answered faster. "Yes Mr Malfoy?" Bella pointed at the platinum blonde teenager at the back, his mouth turned up in, what he thought was, a superior smirk for being called on first.

However, his question was forgotten when he realised she knew his name, "How do you know my name?" He questioned suspiciously.

"You look a lot like your father," he looked proud at the comparison until she continued, "too bad he is an arrogant git. I hope you didn't inherit his attitude." The snort on the other side of the room made her think otherwise.

Turning to see who laughed, she noticed a boy with shocking red hair and gangly limbs covering his mouth, trying to contain his laughter, while the girl with brown busy hair, who was sitting next to him, swatted him on the arm, quietly telling him to behave.

"Mr Weasley, I would prefer if you didn't laugh at other students in any class I teach. And Miss Granger, while I do appreciate you trying to get him to behave, maybe we can refrain from hitting each other, yes?" They both nodded in agreement, their eyes wide in surprise. She noticed a certain dark haired, green eyed, saviour of the wizarding world stare at her with slight suspicion, but she let it go for now.

"Now," her voice suddenly changed into the friendly tone it had when she first introduced herself, "I need to send a message to the good Professor," she ignored the snorts of disagreement from the Gryffindor's side of the room, "before I forget. So please be quiet for a couple of minutes."

She quickly made her way over to Snape's desk, making herself comfortable on his chair, which she was sure he fitted with a bunch of cushioning charms, as a chair like this should not be so comfy. Her hands started flitting over the desk, trying to find something of value, before turning onto the drawers, opening and closing each one quickly. Her movements were stopped when she reached the last drawer, locked of course, her mischievous smile seemed to make the students nervous, not that she noticed of course.

She seemed to get excited as she pulled out her wand enthusiastically; she stood up suddenly and brandished it like a sword. She didn't seem to notice the students jump when the chair crashed to the floor. With some swift movements of her arm and a couple of words being muttered under her breath, the drawer door finally popped open and the strange woman shouted in glee. The potions class couldn't see what she had started to shrink before placing it into her pocket, but they couldn't help but be curious about what she stole. Before they could ask she slammed the drawer door closed and locked it again. If she was correct in her calculations, Severus would not notice it missing for the next 5 – 6 days.

"Now," her voice suddenly became serious, as she turned to face the class, leaning back on the desk. The class soon became confused by her constant mood switching, eyeing each other, as if to figure out what to do next. "Despite all the crazy I just threw on you, I would very much appreciate it if none of you would mention me to your darling potions professor. I mean, I'm sure he knows I am here by now, but I would prefer if he figured out what I took without you telling him."

"And uhh… Who are you Miss?" A boy with a Scottish accent asked from the back of the room, his eyebrows looked like they had only recently grown back.

"I am so glad you asked that Mr Finnegan. I am–"

She was interrupted by a loud booming voice screaming her name "ISABELLA!"

She looked at her watch, "Damn, I thought I would have more time. Oh well," she smiled once more to the class, "remember what I said, no telling the professor I was here, okay?" She had asked as if she was talking to toddlers rather than young adults. Before they could answer, she ran back into Snape's office and down the secret passage (that even Severus didn't know about) before she could be caught.

Immediately the whispers started about who she could be, bets already being made. The main question between the young teens was if she could be, or even could have been, his wife. This continued for over five minutes before an enraged potions professor slammed the door open.

It would have been more intimidating if his robes hadn't been changing rapidly between the colours of the rainbow. When he stalked up towards his office, they could clearly see the words, written in black, on the back of his robes stating:

'You need some colour in your life Sev.

With love, Isabella xo'

Tears had started to form in some of the students eyes as they tried not to laugh, some of the other students were sitting in stunned silence, wondering if they would be in trouble for the mischief that had been caused by the strange woman that just left.

His eyes searched the classroom searching for the culprit, before moving to his office to do the same thing. When he came back, it was clear that he was furious. "Get out. GET OUT!" He shouted at them, making them jump and quickly gather their things, pushing each other out of the way to get to the door first. None of them wanted to be caught in his anger.

When the door finally shut behind the last student, he sunk down into the closest chair available, absently noting that his own was lying on the floor. If she had come back to Hogwarts, then she would be bringing a whole lot of trouble. He was sure of that.

2nd Week of September, Monday Evening

Hogwarts, Dinner, Evening Announcements

Dinner had come quickly, and with it, stories of what happened in the fifth year potions class this morning. Severus snarled at any student that dared to look at him and snigger, despite the fact that he had finally been able to get rid of the curse (it was a charm, but the potions master refused to believe it as such) that had been placed on his clothing (yes, clothing, not just robes).

When the students had finished their meal, Albus Dumbledore stood up for the final announcements, after some final mentions about the toad choir meeting, quidditch practices, and the transfiguration club, he finally brought up the subject of the latest gossip, "As many of you might have heard, there was a… visit from a young woman today." The elderly wizard paid no attention to the soft cursing of the ex-death eater, "You may have also noticed that Madame Umbridge is no longer with us. As it turns out, she was needed quite urgently in the Ministry. Isabella will be coming in tomorrow to take over the Defence Against the Dark Arts classes from now on."

The hall soon erupted into cheers, the Weasley twins started jumping around in circles, bringing other Gryffindor's and neighbouring Hufflepuff's into their circle. The Slytherin's sat at their table, mildly disappointed at the loss of the professor, but curious about the new one, however they had more decorum then the rest of the hall and clapped politely. No one seemed to notice their potions professor gripping the edge of the table with one hand till his knuckles had turned white, while his other pinched the bridge of his nose as if trying to fight off a building headache.

The head of the Gryffindor house tried to hold in her laugh, she had remembered when the two were in school together. If it was anything like that, then it would be an interesting year.

A/N: Hello all! I hope you liked the first chapter of this rewrite. And if you didn't, well, I did. I know Bella in the first 'Isabella Snape' was less… confusing, but trust me; there is a reason why she is like this now. I will be bringing it up in the later chapters, so please be patient. Let me know what you think. Did you like it? Did you not like it? If you didn't like it, why didn't you? I would really appreciate any feedback on this.