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 two
Dinner had come and the rumours about the potions lesson had spread, the animosity between the houses forgotten while people were betting on who Isabella Snape really was. Some say it was Snape's secret wife, therefore explaining why she didn't have a ring, others thought it was his daughter, however this was crossed out as soon as it was suggested, they could not fathom why anyone would have his chid, most people believed that she was Snape's cousin, as there wasn't any resemblance between them, well other than the last name, less believed that she was his sister.

As everyone started to finish eating and the conversations started to die down, Albus Dumbledore – the headmaster of the school – stood up for the final announcement, "Good evening everyone, now that you are all full and have something in your stomachs, I have a few last minute announcements. Firstly, I do not wish for anyone to venture into the forbidden forest especially in these times, I said it earlier this week and I am saying it again," at this he was looking in the direction of Fred and George Weasley – the infamous 'pranking twins', and Harry Potter, Hermione Granger and Ron Weasley – the 'golden trio', he then continued with a smile, "Also, unfortunately Madame Umbridge is needed right now in the ministry, so therefore a new DADA teacher will be coming in tomorrow during breakfast, so I hope that each of you will be there to welcome our new staff member." Everyone, including the teachers, clapped politely, but inside they were having a party, 'anyone had to be better than Umbridge' was going through everyone's minds at the time.

The next morning (Tuesday)
Everyone was excited to find out who was going to replace Umbridge for DADA, this is what made everyone come early to breakfast in the morning, surprising all the teachers who usually have some students coming into their classes late due to waking up so late.

Everyone started coming in and sitting down. Some started eating whereas some were just too excited to eat. Half way through breakfast Dumbledore stood up, his eyes twinkling as he announced to the people present, "The new Defence Against the Dark Arts teacher has arrived," everyone then looked at Dumbledore expectantly, including the teachers, as even they did not know who would be the new teacher would be. "She is an old Hogwarts student and was one of the best students in her time," not many people noticed Snape's eyes grow wider, though everyone did hear a thump, thump, thump, all turning their eyes to the noise, they saw Professor Snape banging his head on the table repeatedly. Dumbledore's eyes twinkled, as he knew that Snape had figured it out but he continued, "Please give a warm welcome to, Isabella Snape!"

As soon as he said this the doors to the Great Hall opened and in came the person that 'entertained' the fifth year students yesterday. Though this time she was wearing her long hair into a loose plait that fell to her waist and instead of wearing a robe, like most witches and wizards, she wore black washed skinny jeans, and a normal white t-shirt that said, 'Should you be looking here?' in black lettering.

People's eyes widened and whispering started around the hall. She saw Severus looking away from her, her hazel eyes twinkled as she ran and sat down on his lap. "Hi Sev," she said very enthusiastically, and very loud. This caused some laughs between the students and teachers.

"Bella," he said quietly.

"Yes?" she mockingly questioned.

"Get off my lap."

"Aw," she complained, "why? You're so comfy." This brought laughs throughout the teachers around them who were the only ones who could hear them properly. Next thing Bella and everyone else knew, Bella was on the floor, it seems Snape had enough and pushed her off his lap. Next thing they heard…

"Severus Tobias Snape! How dare you push your SISTER onto the floor, really, what would mom say?" Though her voice was pissed off the huge smile on her face betrayed what she really felt. (No one had bet that she was his sister so no bets were exchanged)

Everyone was sad when the bell had rung for their first class, including the teachers, as their entertainment had been stopped. Still smiling, Bella took a piece of toast from Snape's plate and ran off to her classroom, eating it along the way.

Harry and Ron asked Hermione what class they had first, as she had already memorised all their classes, seeing as Harry and Ron would probably have lost their timetables anyway. Hermione had excitedly said that they had a double period of DADA first and then followed by a double period of Potions. The trio practically ran to the DADA classroom, surprised that they did not find their teacher there, considering she left before them. The other students started filing in, also surprised that their teacher wasn't there.

As soon as the last of the students came in, the door suddenly closed and locked itself. All looking around for the teacher, they still couldn't find her. A voice then said from somewhere, "First lesson. Always be on the lookout for your opponent. Look up." They did as she said and found her on the rafters. She then jumped down, landing on her feet, with a slight bounce.

"Okay," she said looking around the class, "Didn't I have you lot yesterday in Sev's class?" a lot of them nodded, "Okay. First off, my name is Bella. Repeat after me, Bel-la." They did as she said, "It is not Isabella. It is not Professor Snape, Miss Snape, Miss Bella or Professor Bella, just Bella." They nodded. "Second, I'm sorry I had to leave you with toad face for a week, now I would have come earlier but I had to do something for Professor Dumbles." They all laughed at her nicknames for them. "Thirdly, I will not put up with any blood or house prejudices in this classroom… leave them in your dormitory people and fourth thing, what have you done while I was away?" Everyone started shouting, Bella then put her hands over her ears and started making random noises till the class quietened down, "Okay," she said with a sigh, "Lets make fourth, when I ask a question, you put your hand up, and fifth, what have you done while I was away?"

Everyone put their hand up, "Yes Miss Brown," she said looking at Lavender, "Um, we went through this book and had to take notes." She explained, holding up the book Umbridge had given them. Bella took the book out of her hands, flipped through it and threw it behind her, "well that's no fun, is it?"

She walked to the front of the room and asked, "Now… what do you think are considered 'dark' spells?" Immediately, people started naming the unforgivable curses and other curses considered 'dark' by the ministry, she wrote these on the board with the chalk she stole from her brother yesterday. Once everyone stopped calling out and she had finished writing, she put a cross through the whole thing leaving the teenagers confused.

"These spells can, in fact, be used to kill and hurt people, however this is not what was intended when the spell was made." People looked at her with confused expressions, "okay, it's like this," she said before sitting cross legged on her desk, "The killing curse, incantation is Avada Kedavra, best way to stop it? Don't be there when it's fired… either that or dodge the spell, which we will be learning to do at a slightly later time. 'Avada' is taken from the, slightly overused, word Abracadabra and is an ancient spell, originally in Aramaic. It was used to 'cure' the illness. However, 'Kedavra' changes it slightly. 'Kedavra' was influenced by the Latin word Cadaver which means copse. So in some, weird, way it kind of… says that the 'illness' is the body and… VOILA you have the killing curse. Did you know that this spell wasn't meant to be a 'dark' spell? It was actually created to kill dying or sick animals painlessly so they would not suffer and so the people would have meat that was not infected by the disease. I mean you could easily kill someone by levitating them off a cliff or something…"

The lesson continued and the class sat there, listening.