There was shocked silence around the hall, especially at the Gryffindor and Slytherin tables. I looked around. Ron was staring at Sarah with his mouth open. Demelza was gnawing on her lip and looked very confused. Amy looked like she'd just encountered another Dementor. Luna only looked as if she found the situation mildly interesting. Avery, Mulciber and Yaxley however looked very happy, as if some grand plan of theirs had succeeded, and they fist bumped each other.

Sarah jumped off the stool and to even bigger shock than before, walked confidently over to the Slytherin table and sat down gladly next to Avery. Muttering now started breaking out around the hall. I caught a few of the words that were said.

"A Bagman in Slytherin, whatever next?"

"Maybe those rumours of Ludo being a Death Eater were true after all"

"They fucking weren't!" said Amy angrily to that person.

"Silence!" called Dumbledore. The sorting continued, but we didn't pay much attention to it. All Demelza, Amy, Ron and I could think about was how Sarah had ended up in Slytherin.

Eventually Harry and Hermione showed up, after the sorting had finished. People looked around at them as they passed along the back of the hall, and a few of them pointed at Harry. Had the story of him collapsing in front of the Dementor travelled that fast? He and Hermione sat down on either side of Ron.

'What was all that about?' he muttered to Harry. Harry started to explain in a whisper, but at that moment the Headmaster stood up to speak, and he broke off.

Professor Dumbledore, though very old, always gave an impression of great energy. He had several feet of long silver hair and beard, half-moon spectacles and an extremely crooked nose. He was often described as the greatest wizard of the age, but that wasn't why we respected him. You couldn't help trusting Albus Dumbledore, and as we watched him beaming around at the students, we felt really calm for the first time since the Dementor had entered the train compartment.

'Welcome!' said Dumbledore, the candlelight shimmering on his beard. 'Welcome to another year at Hogwarts! I have a few things to say to you all, and as one of them is very serious, I think it best to get it out of the way before you become befuddled by our excellent feast …' Dumbledore cleared his throat and continued. 'As you will all be aware after their search of the Hogwarts Express, our school is presently playing host to some of the Dementors of Azkaban, who are here on Ministry of Magic business.

'They are stationed at every entrance to the grounds, 'and while they are with us, I must make it plain that nobody is to leave school without permission. Dementors are not to be fooled by tricks or disguises – or even Invisibility Cloaks,' he added blandly, and Harry and Ron glanced at each other. 'It is not in the nature of a Dementor to understand pleading or excuses. I therefore warn each and every one of you to give them no reason to harm you. I look to the Prefects, and our new Head Boy and Girl, to make sure that no student runs foul of the Dementors.'

Percy, who was sitting a few seats along from us, puffed out his chest again and stared around impressively. Dumbledore paused again; he looked very seriously around the hall, and nobody moved or made a sound.

'On a happier note,' he continued, 'I am pleased to welcome two new teachers to our ranks this year. 'Firstly, Professor Lupin, who has kindly consented to fill the post of Defence Against the Dark Arts teacher.' There was some scattered, rather unenthusiastic, applause. Only those who had been in the compartment on the train with Professor Lupin clapped hard, myself among them. Professor Lupin looked particularly shabby next to all the other teachers in their best robes.

'Look at Snape!' Ron hissed. Professor Snape, the Potions master, was staring along the staff table at Professor Lupin. It was common knowledge that Snape wanted the Defence Against the Dark Arts job, but even Harry, who hated Snape, was startled at the expression twisting his thin, sallow face. It was beyond anger: it was loathing.

'As to our second new appointment,' Dumbledore continued, as the lukewarm applause for Professor Lupin died away, 'well, I am sorry to tell you that Professor Kettleburn, our Care of Magical Creatures teacher, retired at the end of last year in order to enjoy more time with his remaining limbs. However, I am delighted to say that his place will be filled by none other than Rubeus Hagrid, who has agreed to take on this teaching job in addition to his gamekeeping duties"

Demelza, Amy and I looked at each other, stunned, then joined in with the massive applause from the Gryffindor table. We would have to take Care of Magical Creatures next year if Hagrid was in charge!

'We should've known!' Ron roared, pounding the table. 'Who else would have set us a biting book?'

Harry, Ron and Hermione were the last to stop clapping, and as Professor Dumbledore started speaking again, they saw that Hagrid was wiping his eyes on the tablecloth.

'Well, I think that's everything of importance,' said Dumbledore. 'Let the feast begin!"

As we began to pile food on to our plates, Hermione suddenly noticed the empty seat next to Amy.

"Amy, where's your sister?" she asked

"In Slytherin" said Amy in an undertone.

"What? Really?"

"Yes, look"

Amy pointed to the Slytherin table, where Avery was now conversing with Sarah.

"I swear if she does anything to Sarah I'll punch the shit out of her" said Amy savagely.

"They seem to be talking in a pretty confident and friendly way" I said "Bloody hell, it looks like they may even be friends!"

"I never thought these would be the type of mates Sarah would have. I didn't bother to ask her. The idea of her being in contact with evil bitches like her never crossed my mind. I wish I'd said something, then maybe I could have stopped this" Amy replied mournfully, picking at her food.

"Look, Amy, it isn't your fault" said Demelza "you couldn't possibly have imagined something like this, neither could any of us, don't blame yourself mate". She patted Amy on the back. When the feast is over we'll go and talk to them ok, we'll get to the bottom of this"

"Too right we will, then I can give Avery the biggest warning she's ever had"

At long last, when the last morsels of pumpkin tart had melted from the golden platters, Dumbledore gave the word that it was time for us all to go to bed, and we got our chance.

Whilst Harry, Ron and Hermione went to talk to Hagrid, Demelza, Amy and I found Sarah, Avery, Mulciber and Yaxley and cornered them in an empty classroom. Amy threw Avery up against a wall.

"Right, listen you, if you try and hurt my sister in ANY way, or try to convert her to your bullshit pure blood supremacist views, you're going to wish you'd never been born, DO YOU UNDERSTAND ME?!"

Mulciber, Sarah and Yaxley tried to intervene, but Avery simply held up her hand and started laughing.

"Oh my dear Bagman, you don't think this was just a spontaneous, random event, do you? The truth is, I've known Sarah here for ages now. Once I found out last year that you had a sister, I started sending her owls, I've been talking to her for so long, so have Calo and Aires. She already knows what the right side is, and who the right people are. She knows they aren't you three, or any of you blood traitor muggle loving fools. The friend she's been visiting this summer has been me"

Amy's grip lessened, and her hands started shaking. This couldn't mean what we we thought it did, surely?

"That's right" said Sarah, and Amy now fully released Avery and turned to her sister. "Lillian has really opened my eyes to what a terrible family I had, and what terrible views I was bought up to believe. I've wanted to be in no house other than Slytherin for a long time. In fact, I consider myself to have no real family anymore. I plan to get myself emancipated and live with Lillian after this year at Hogwarts"

Demelza and I exchanged a look and backed away somewhat, as Amy approached Sarah and got down to her knees. This had to be a conversation the 2 sisters had, we couldn't intervene.

"Sarah, look. I know you want to be different to the rest of the family, but this is too far, way too far! Surely you know what this is, Avery is the child of a Death Eater, all 3 of these girls are. You don't want to grow up into one of them. Come on, come back to me, and you can be as different as you want"

She reached out a hand and stroked Sarah's cheek.

Sarah violently slapped it away, and started laughing, as did Avery, Mulciber and Yaxley

"You silly little bitch!" Sarah snapped. "Do you really think I'm doing this just to be different? Do you really think I haven't considered everything? Do you really think that I don't actually believe this is the right way to go? Well I've got some news for you, sunshine! This is the right way to go, I've known it for a year now, I've just been pretending to be my old stupid self and my god has it been annoying! Anyway, I'm off with my friends, to my common room now. Go and take yourself and your stupid friends off to yours!"

She spat in Amy's face. This was too much for me.

"OI!" I yelled, and pulled out my wand "you show your sister some fucking respect!"

Sarah turned to me

"I have no sister"

And with that, the 4 of them ran off towards the dungeons, leaving Amy kneeling there, staring at the ground, and weeping.