Hermione blinked at the latest of her housemates to take offence to her. "What do you mean, what am I doing?" she asked. Did he mean just existing? Because she wasn't sure what she was supposed to do about that. She wasn't going to curl up and die just because some girl who said her name was Margaret Nott, as though that meant anything, said she didn't belong here.

"You must be thicker than you look," he hissed at her, looking around even though he had only just done so, having dragged her away from the entrance to the common room into a side corridor. "This is Slytherin house, you stupid girl. No Muggleborns."

"But I am Muggleborn," she explained. He shook his head, laughing bitterly.

"Are you simple? If you're Muggle-born, you need to hide that fact. Your first week at Hogwarts and you've turned your entire house against you," he sneered. "Good job. Really."

He seemed just as upset with her as everyone else in Slytherin house was at her parentage. But his negativity seemed more – angry, than judging or offended, she realised. That was new. His face was flushed pink with how exercised he seemed about this.

"It – you have to hide it if you're Muggle-born?" she asked him. He rolled his eyes and swore under his breath.

"Yes, Granger," he said, as though it were obvious. No one had told her you had to lie about being the first in your family to have magic, so Hermione didn't know how she was supposed to have known.

Maybe this boy was Muggle-born too? This was a different sort of reaction than what she had put up with in her dorm on the first night at Hogwarts, or experienced in the common room or dining table in the days following that, after an entire house of students became obsessed with the fact her parents were dentists. There might have been a few unspoken rules she had accidentally transgressed, she was starting to realise.

She stuck out her hand, determined to try and make the most of the bad situation she had landed in. "My name's Hermione," she offered. He looked at her hand like it was coated in something disgusting and she dropped it again. Ok, maybe not Muggle-born, then. Or he was, and was just very rude.

Hermione wished Professor Dumbledore had given her a few more pointers when he visited earlier in the year to invite her to Hogwarts. All the text books she had read were on magic itself, not all the strange cultural idiosyncrasies surrounding it.

"I'm Tom Riddle," he said, again like it was supposed to mean something. They all seemed to think highly of themselves in Slytherin, she realised. Maybe this was standard for fancy schools. Hermione hadn't been to one before.

"Right," she said. "Well, Tom, I didn't know it was something you had to hide. Sorry if that broke a rule or something."

His eyes narrowed. "Of course it did," he said thinly. "There hasn't been a Mudblood in Slytherin since Hogwarts was founded almost a thousand years ago. You've gone and put the cat amongst the pigeons. Here's what you need to –"

"Slytherin is for people with – pure blood only?" Hermione asked. She had read that Salazar had left the school because of his blood purity views that clashed with the other founders. But that was almost a thousand years ago, as Tom had said. Was Slytherin house as a whole still not letting Muggleborns in? That might explain Margaret's frankly hysterical reaction.

"Should I be in a different house instead?" Hermione asked. If she could change houses, that might be for the best. The other houses surely wouldn't be this torn apart by the concept of being Muggle-born, or refer to themselves in the third person like they were royalty.

"Of course not, you idiot," Tom said loftily. "The Sorting Hat is a powerful magical object, imbued with the intelligence of –"

"- the four founders of Hogwarts," Hermione finished. "Yes, I know." She was not an idiot.

Tom blinked. "Well, then, if you're so knowledgeable, you should be aware that the Hat is much more powerful than some silly eleven year old child. If it said you should be in Slytherin, then that is where you belong. It must be right and you must be wrong."

She was confused. So she did belong in Slytherin house? But Tom was already walking off, calling out for her to follow him. Hermione tripped after him, back up the stairs and into a wing on the second floor.

"This is the –"

"Wow!" Hermione gasped, looking at the books. It was a library, bigger and better stacked than the book shop she had visited with her mother. That had looked so tantalising Hermione could have happily moved into it and never left – this was the best thing she had seen since arriving at Hogwarts, possibly ever. "This is the school library? Oh my goodness!"

"Yes," Tom said smugly. "It's very impressive, isn't it?" He walked off again, and Hermione followed him, trying not to get side tracked by the titles on the volumes stacked on the shelves.

"You," he said, stopping at one particular row of cabinets, "will be spending your weekends here. You need to find a magical ancestral link. Maybe it's not your parents, maybe it's a grandparent or something. But Muggleborns do not get sorted into Slytherin. Your life will be a lot harder until you find the link, so – get started."

She opened one of the cabinets and pulled out a huge box of carefully filed newspaper announcements of births and deaths. Looking for something she was sure she wouldn't find didn't seem to be an exciting use of such a wonderful place. How much magic was described in all the books here? She wanted to get started reading about that instead.

Hermione looked at Tom, who was staring at her with a narrowed look of disdain. He did seem very sure about this. If he was so certain, and knew so much about how being Muggle-born was bad in Slytherin house, he must have knowledge of it first-hand. She pulled out a newspaper clipping from the box and watched the text on it flicker around the pages, moving with magic.

"Have you found your link yet?" she asked. The boy froze up in the corner of her eye, and Hermione glanced up at him. He looked furious again.

"I – just mean, if you know about all this," she continued, gesturing at the cabinet. "I presume the rest of them already know who their magical family is." Margaret Nott, the blonde girl in her dorm had shrieked, like the name was the earth on which she could stand.

He pursed his lips at Hermione, clearly deliberating what to say. He was quite – pretty, for a boy, she realised. When he wasn't absolutely seething with rage, at least. All fine features, those long eyelashes that boys in general seemed unfairly blessed with compared to girls.

"No," he eventually replied, voice ice cold. "I'm an orphan. I have all of three names to go off, one of which is Tom."

"Oh," Hermione said. "I'm sorry."

He was back to looking infuriated. She was only trying to be polite – did everything make him angry? "You'll be a lot more sorry, if you don't do what I tell you," he hissed, leaning over the cabinet to threaten her. "Until you find a magical relative, you're going to have to try twice as hard as the rest of them. You'd better not embarrass Slytherin house, or me, by being useless. Or you'll have me to answer to."

Hermione put the newspaper clipping down on top of the cabinet, gripping the edge of the cabinet with her fingers. "I won't be useless," she said tersely. "I always try hard at school. I study really hard."

"I don't care about how hard you work," Tom sneered. "I care about results. You better be one of the top students, Granger. And you better not cry easily, because they'll smell the weakness like blood in the water."

She pulled herself up as tall as she could, staring him straight in the face across the cabinet. "I can handle bullies. I won't cry. And I always get top grades." She crossed her arms, trying to match the smug level of certainty on his face. "And it's Hermione," she added. The aversion to given names at this school was really quite odd.

He blinked, but she continued to stare right back, not backing down. "We'll see, won't we," he replied after a moment, leaning back out and folding his arms. The judgment and doubt was written all over him. She hated it.

"You will," she promised him, turning back to the newspapers and starting to scan for her last name. What a nasty, angry boy. She'd show him.