Summery: Bella was left alone in the forest, however she never told Edward, or any of the Cullen's that she was not Bella Swan – Chief Police Swan's daughter. Instead she is Isabella Snape, a sister to the most hated teacher at Hogwarts School of witchcraft and wizardry, a witch and an unofficial Marauder. What happens when Professor Dumbledore invites the Cullen's to Hogwarts to help protect the school? Will there be chaos? Or will there be love?

Disclaimer: I do not own Twilight, Harry Potter or other things that may appear in this story, if you see something familiar; it's probably not mine. I do, however, own this plot and possible new characters.

Chapter One
Hogwarts (Monday)

It was a normal Monday morning in Hogwarts… well, as normal as it can get considering it's a training ground for underage wizard and witches. Well, at least, it would have been normal if a girl were not climbing out of a small hole in an office that was covered by a table in the corner. This office belonged to none other then Severus Snape, the most hated teacher in Hogwarts.

Outside the office was a group of fifth year Gryffindor and Slytherin students sitting in the potions classroom, found in the dungeons, waiting for the aforementioned teacher. However, the potions master was… busy, to say the least. The long brown haired girl looked around the office, and dusted off her jeans and t-shirt which said, 'I don't have a drinking problem, I'm just really thirsty.' As she was doing this she sighed, and quietly spoke to herself, "You never change Sev. You never change."

Sighing once again she decided that since Severus was 'busy', she would amuse the students for a while. So once she was sure that they were all there she opened the office door with a big bang making everyone look in her direction. Smiling hugely she spoke, "Hell-llooo kiddies!" Everyone was looking at her weirdly, "My name is Bella. Professor Snape is… cough, 'busy' for the next oh," she looked at her wristwatch, "I'd say 45 minutes, so I have decided to come entertain you for a while. Any questions?"

Nearly everyone put up his or her hands, "Yes, Mr Malfoy," she said pointing to a platinum blonde haired kid. Forgetting what he was originally going to ask he said, "How do you know my name?" they all became curious, "You look a lot like your father," he seemed proud for a second before she continued, "too bad he was an arrogant ass, hope you didn't inherit his attitude." The snort on the other side of the classroom made her think he did.

Turning to see who laughed she saw three people, two boys and one girl, trying to contain their laughter, "My, look who we have here, Mr Weasley, I presume," she said looking at the orange haired teenager, he nodded, "Mr Potter as well," the raven haired teenager nodded silently, "and Miss Granger I do believe," the bushy brown haired girl nodded wide eyed.

"Any who," Bella said suddenly, "we have another…" she checked her watch again, "35 minutes left, and I need to send a message, where's the chalk?"

Hermione Granger, the bushy brown haired girl put up her hand and told her that Professor Snape kept the chalk in the top drawer of his desk, thanking the girl, she turned to open the drawer… only to find it locked, "Locked?" she disbelievingly asked to no one in particular as the class laughed quietly, "Who in their right mind keeps CHALK locked?" she then took out her wand and pointed it at the desk while muttering a few things under her breath, it opened soon after that, "Too predictable Sev, too predictable." She said while taking all the chalk and stuffing it in the front pocket of her pants.

"So I have you for about another 30 minutes and I have decided to let you in on a few ways to annoy your 'beloved' potions professor." The Gryffindors were listening intently; as were the Slytherins, though they tried to seem not interested, "First off, laugh whenever he comes into a room, he hates it when he doesn't know what everyone else is laughing about. Number two; always call him Sev, or Sevvy. He hates those nicknames, especially when I call him that," She shrugged but continued, as she went to the desk at the front of the room and sat on it, tired of walking around the class, "Numero three, mention me,"

"And, em, who are you exactly?" Harry Potter asked, "Well, I'm glad you asked Harry Potter, why I am…" however she was interrupted by a loud voice shouting "ISABELLA SNAPE!"

Her eyes widened slightly before smiling again and saying to the teenagers in front of her, "and that is my cue to leave, excuse me" before running back into Snape's office and down the hole. Soon after that the class started talking amongst each other, mostly saying things like, "'Snape'? As in PROFESSOR Snape? Is it Professor Snape's wife or something?" however Hermione stopped all this saying, "It wasn't his wife." Everyone turned to her, even the Slytherins who despised her silently asking her to explain, she sighed, "Honestly, she didn't have a wedding ring on," she said as if it were obvious, "so it has to be a relative he must have." As soon as she finished saying this the enraged Professor Snape came in, though his normal robes (which were usually black with green and silver edges), were replaced with a different set of robes. Instead of the green and silver was pink and yellow and on the back in a bright lime green and constantly changing colours had the words 'Courtesy of Isabella Snape' with a smiley face on the end. It was very hard not to laugh at him.

When he looked around and saw that she was not there he got into a worse mood, glaring at the class in front of him he sneered at them before saying, "well, what are you waiting for? Get your things out." Trying not to laugh at him the teenagers got out their stuff while Snape went to his desk to get some chalk… only to realise it wasn't there, which made him in an even worse mood. He just pointed to the door and as calmly as he could (which wasn't very calm), told the students to shove off.

If she was back, it usually meant trouble.