I do not own Sirius Black or any of the characters that have come from the amazing Harry Potter world we all know and love.

I hope you enjoy reading my story as much as I've enjoyed writing it. I only ask that you are respectful if choosing to share your thoughts.

Please also note: later chapters do include highly sexual content, so please only read if you are comfortable with that.

Part I

August 1976

Chapter 1: New Rules

Gemma took a deep breath. She could do this. She could definitely do this.

After all, she was Gemma Arwin. Sixteen year old witch, enrolled at Hogwarts School of Witchcraft and Wizardry and she was a Gryffindor for Merlin's sake. She could definitely – maybe – do this.

Staring at her foe who was currently blocking her escape route, she sized him up again. Then shuddered. He was big. Big body. Long legs. So many fucking legs.

Why did spiders have to be so creepy?

Steeling her spine and calling upon her Auror blood, she stepped forward. It moved.

"Fuck!" Gemma leapt back, warily watching as it paused again. He was going to make this difficult for her. He was going to force her to live the rest of her life in her bedroom. She was going to die here, from starvation and thirst, curled up in the middle of her bed wearing her cat pyjamas and hugging her childhood teddy bear.

A knock on her room door startled her and her heart rate picked up as she watched her nemesis shuffle slightly to the side, towards her wardrobe. That was the last place she wanted him to be – snooping around in her clothes – no thank you.

"Gemma, darling. Can I come in?" Her mother, Cynthia Arwin, called through the door and Gemma breathed a sigh of relief. She was saved. Her mother would handle this.

"Yes, but very slowly. There is an absolutely enormous spider by the door and I do not want it running towards me or finding somewhere to hide."

Her mum opened the door slowly and peeked her head in, spotting the spider quickly. "Oh, he's not that big." She said, pushing the door open further and stepping towards the enemy. Gemma closed her eyes as her mother bent to pick him up – with her bare hands – and took him outside. Doing a quick sweep to check he didn't have any family close by, Gemma relaxed and sat back down on her bed, waiting for her mum to return.

"Your letter arrived this morning." Her mum said as she stepped back into the room. "I thought we could head into town, pick up your supplies and maybe meet your dad for lunch. He's gone in for another meeting."

Her father, George Arwin, was a retired Auror – as was her mother – although he was often pulled in to do work with the Ministry of Magic as a consultant. George's expertise in the field was highly regarded, and he was currently working with a young Auror, Alastar Moody. It was a high profile case, with possible links to Voldemort; the dark wizard currently waging war on the whole wizarding community. And the muggle community, if recent reports were to be believed.

"That will be nice. I'll get ready." Gemma stood and moved towards her wardrobe, giving the inside a quick check before picking an outfit. Her mother laughed from behind her.

"If you're going to be an Auror, dear, you're going to need to get over your fear of spiders. You'll be facing bigger and badder things out in the real world, I'm afraid."

Gemma rolled her eyes. "I know, mum. But those other things don't scare me. At least, not in the way spiders do. I know it's irrational, but they are creepy. And as my mum, you have to love me as I am, right, so let's just forget it?"

She turned and grinned at her mum, who was smiling back. "Yes. Now, what do you want for breakfast?"

"I'll just grab a bowl of cereal. I'll make it when I come down."

"Ok, darling."

Her mum left, and Gemma headed to the bathroom for a shower. Dressed in a pair of light blue fitted jeans and a pale yellow summery top that complimented her wavy blonde hair, Gemma went downstairs. Fixing up a bowl of her favourite cereal – coco pops - she grabbed her Hogwarts letter from the side and began to read.

It covered the usual – welcome to your sixth year, here's a list of books and supplies you'll need – but there was an additional section which caught Gemma's eye. Shovelling a spoonful of chocolatey milky goodness into her mouth, she read the paragraph.

This year at Hogwarts School of Witchcraft and Wizardry we are excited to announce a new student development programme. Its purpose is to provide all students with equal opportunity to gain support and learning from others. Within every year, students will be paired together for classes, assignments and practical studies.

Gemma frowned, looking away from the note as she grabbed another spoonful of cereal. She was going to be paired with someone. All year. It wasn't uncommon for them to work in pairs in class, but usually it was whoever you sat next to that day, not a regular pairing. And most of the time the work was done in isolation.

Reading the note again, it seemed all work was to be done with this second person, even assignments and practical work. Did that mean they would be graded as a pair as well? Gemma really hoped not. Her NEWT exams were next year and they were a critical step to her being accepted into the Auror Programme. She couldn't afford any mistakes.

Glancing back down, she read the rest of the note.

These pairings have been designed based on recognised abilities and are to be respected at all times. Miss Gemma Arwin, we are pleased to inform you that your partner is Mr Sirius Black.

Gemma slowly chewed another mouthful as she processed the news. Sirius Black was a friend, so that was a positive start. He was also intelligent, quick on his feet and hardworking when he wanted to be. He was, however, easily distracted. He and James – his best friend – were known for playing pranks on each other, even in class. Sometimes they extended the pranks to their other best friends, Remus and Peter, and sometimes to some poor unsuspecting student.

Gemma smiled as she remembered the first – and only – time they had pulled a prank on her. It had been their second year and she had fallen asleep in the common room after a long night of studying. She had been awoken in the morning by laughter, and when she had rushed to her dorm in a panic she had spotted herself in the mirror. Sirius and James had dyed her hair pink. Bright luminous pink. She looked utterly ridiculous and was unable to change it back until the spell faded, which took almost two weeks. While she was mortified, she had bravely weathered the storm as she planned her revenge.

And that revenge had come on the day Gryffindor played Slytherin in the Quidditch Cup Final. The night before, Gemma had sneaked into the boy's dorm and given them a dose of their own medicine. Literally. She had amended the spell though - instead of it lasting two weeks, it had only lasted two days, but instead of bright pink, she had charmed their hair to turn silver and green – Slytherin's colours.

Holding on to just a small amount of regret and healthy dose of fear over how they would retaliate, she had stood tall as they had come charging down the stairs. Their eyes had been blazing and for a moment Gemma had wondered if she was about to be challenged to a duel. But then Sirius had smiled, and James had laughed.

While she had offered to undo the spell ahead of the game, they both agreed that they deserved the ridicule and accepted their fate with grace. After that, a new friendship began.

Finishing her breakfast then running upstairs to brush her teeth, Gemma grabbed her bag and shoved the Hogwarts letter inside. Then she met her mother in the living room, ready to travel to Diagon Alley via the Floo Network.

Sirius Black stepped out of Flourish and Blotts and headed over to join James Potter, Remus Lupin and Peter Pettigrew with a smirk on his face. He'd just convinced a soon to be second year student to purchase a book about the Occult Philosophy. Sirius wished he could stay and watch the shocked reaction of the uptight bookkeeper, Mr Levine, when the twelve year old tried to purchase a book banned in over sixty countries. But he had needed to make a quick exit.

Mr Levine had been keeping a close eye on him since the moment he had stepped into Flourish and Blotts. As if Sirius was some sort of criminal, unable to pay for his school books and therefore needing to steal. Sirius scoffed at the thought. He might not be close with his wealthy family – understatement of the year – but they had provided him with enough funds for school and he wasn't so immoral that he would take what wasn't his. In that regard, he was nothing like his family.

"What took you so long?" James asked as Sirius joined his friends. His fellow Marauders. It was the name they had for themselves - they got into scrapes and laughs together, they played pranks and wound each other up. But they had each other's backs. They helped each other, supported each other. They were family.

James was his best friend though, a true brother in every sense but blood, and he was often leading the pranks and the laughs with Sirius. But today James had run out of the shop the second he'd made his purchases, hoping to catch another glimpse of Lily Evans, a fellow Gryffindor student and the girl James was madly in love with.

"No reason. I was just having a little fun." Sirius smiled as he started walking towards Florean's Ice Cream Parlour. The others fell into step beside him, with James wanting details, and Sirius being more than happy to provide. No doubt James planned to steal the idea.

"So, did everyone else get that extra little note in their Hogwarts letter?" James asked, turning to look at Peter and Remus, as well as Sirius.

"Yes, and I don't think you're going to like who I'm partnered with." Remus replied, giving James a sad smile. "Lily."

"Dammit! I wondered who she would get, but I figured it would be Gemma. I got Alice, which means I'm going to have my balls handed to me every day. That girl scares me."

Sirius tried to hold in a laugh. Alice Fortescue was definitely tough, and she was not a fan of James. Or Sirius, for that matter, or any of the Marauders. James was going to have his work cut out for him if he wanted to keep his male appendages intact.

"I got Gemma." Sirius said, feeling a little smug. With the exception of being paired with one of these three, getting Gemma was a great deal. She was smart enough to keep him on his toes, and fun enough that he wouldn't get bored.

Despite not really speaking to her much for their first two years – hair dying incidents aside – Sirius had seen a new side to Gemma at the start of their third year. He and James had been walking the corridors when they had heard a struggle. Turning the corner they had been shocked to see Mulciber – a tall, bulky Slytherin bully – grabbing hold of a young, female student. Before they could intervene, Gemma was already there, pulling Mulciber off the girl and shoving him backwards.

Given Gemma was half Mulciber's size, and a year younger, it was impressive. She had drawn her wand, told him to back off, and hadn't even flinched as Mulciber and his two friends – Avery and Lestrange – drew their wands in retaliation. In fact, she looked ready and willing to take all three on.

Sirius and James had jumped in though, drawing their wands as they stood behind Gemma, letting the Slytherin's know that no one messed with a Gryffindor.

After checking on the young girl, Sirius and James had walked Gemma back to their common room. Her anger at Mulciber and the injustice of someone being attacked simply because their parents were muggle was admirable. Especially when she hadn't even known the girl. Despite being just thirteen, Gemma had proudly announced she was going to become an Auror and make the wizarding world a better place. Sirius knew then she was a force to be reckoned with.

He, James and the others had happily looked out for her over the years that followed, working with her in class, writing some assignments together, and generally enjoying her company whenever she was around. She wasn't a Marauder, not by any stretch, but she was a good friend.

Yeah, he'd definitely gotten the best pairing.

Hearing his three friends laughing at something Peter had said, he pulled himself out of his thoughts just as they arrived at the ice cream parlour. As they walked to the table, Remus and Peter continued to make jokes about James's pairing with Alice, and making guesses at other student pairings. It eventually became a game, with each friend trying to come up with the most unusual or hilarious pair.

An hour later, after eating their body weight in ice cream, Sirius said goodbye to his friends. It was only two in the afternoon, but they all had welcoming homes to return to. Sirius intended to avoid returning home for as long as possible. Welcoming was not the word to describe his home environment.

While his father was mostly absent – which suited Sirius just fine – the same could not be said of his mother, who was by far the worst of his parents. She seemed to make a point of being around, making Sirius's life as unpleasant as possible, and cosying up with his younger brother, Regulus, to really drive the nail in the coffin. Regulus was apparently everything a perfect son should be, while Sirius was the devil himself. He scoffed at the thought. Only the devil would get into bed with Voldemort, and that was exactly what he suspected his mother was doing.

At the start of the summer, Sirius had promised himself that he would move out as soon as he turned seventeen. The Potters had already offered him a bed, so between there and Hogwarts, he would be able to survive until he needed to find a job. Just a few more months until November, then he would be free of the shackles. In the meantime, he would continue to keep his head down. He'd started running, mostly as an excuse to get out of the house, but that had quickly led to a more rounded daily workout which gave him focus away from his crumbling family tree. Maybe he'd need to run again today, given the amount of ice cream he'd just eaten.

Deciding to head towards Gambol and Japes Joke Shop, Sirius shoved his hands in the pockets of his jeans and began a slow walk down the cobbled street. Bored now that he was alone, he kept his focus on the ground, not seeing the similarly distracted person ahead of him until it was too late. Bumping against a small, soft body, and hearing a light, feminine gasp, Sirius reacted instantly, grabbing hold of the slender arms in front of him and preventing his assailant from falling backwards.

Recovering quickly, Sirius looked up at the person in his arms and smiled when he recognised her.

"Gemma." He said, his eyes casually raking over her. Her blonde hair was loose around her pretty, pixie-like face, curling in long waves down her back. She was dressed for summer, wearing tight jeans, barely-there strappy shoes, and a thin yellow top that hugged her slender figure and drew his eye to the curve of her breasts.

Gemma cleared her throat. "I'm up here, Sirius."

He raised his gaze back to her face and grinned. He could see her lips twitching too. She was trying not to smile. "Apologies." He nudged her arm playfully. "Good to see you, Gemma. Although if you wanted my attention you didn't have to crash into me like that."

"I know. I'm sorry. I guess I was lost in my own thoughts." She tilted her head to the side. "Are you ok? Did I hurt you?"

Smiling at her concern, given he was a few inches taller and had far more muscle on him than her, he gave her a reassuring smile. "I'm good. You might throw a powerful spell but I don't think you're strong enough to knock me over."

Gemma laughed and raised her arm to show off her non-existent bicep. "I don't know. I reckon one of these days I can take you."

Sirius grinned in response then held his hands up in mock surrender. "If I promise to behave, will you let me go in one piece?"

Gemma laughed. "You, behave? I'm surprised you know the meaning of the word."

"I've heard it somewhere before. It means to 'have fun regardless of consequences', right?"

Gemma laughed again. "Right." At that moment she looked quickly over his shoulder and gave a quick wave. Then she focused back on him. "I need to go. My parents are waiting for me. It was good to see you. See you next week." Without waiting for a reply, she dashed off, running awkwardly up the cobbled street in those weird barely-there shoes.

Sirius turned and continued heading to the joke shop. Bumping into Gemma had been too short a distraction. Hopefully Gambol and Japes would distract him long enough that he wouldn't need to return home until dinner time.

Gemma half ran, half stumbled up the cobbled street towards her parents. Stupid sandals. It had been nice bumping into Sirius. Besides meeting her friend, Lily Evans, earlier at the stationary store for writing supplies, she hadn't seen anyone else over the summer.

Alice Fortescue, her best friend, was often travelling around some exotic place during the summer, and right now she and her family were in Morocco. Mary MacDonald was splitting her time between her divorced parents, trying to keep the peace. And Lily, while allowed to visit Diagon Alley to collect her school supplies, was encouraged to minimise her links to the magical world when she was home. Her parents were muggles, and although they accepted her as a witch, it apparently made her little sister upset.

Finally reaching her parents, Gemma smiled up at them, offering to take some of the shopping.

"Was that Sirius you were just talking to?" Her mum asked, offloading one of the heavier packages of books into her daughter's arms. "He looks a lot more grown up than the last time I saw him."

Gemma managed to avoid rolling her eyes in humour. "Well, given the last time you saw him was about two years ago, I'm not surprised he looks more grown up. He is sixteen now."

Although, Gemma had noticed that he had seemed taller somehow. He was just as good looking as always with his strong jaw, piercing grey eyes and too-long dark brown hair, but he was also a lot harder than she had realised. When she had accidentally bumped into him, she hadn't quite expected his body to be a rigid wall of muscle. It was surprising.

"Come on you two. Stop gossiping." Her dad had turned and was already walking away, signalling that they were leaving. When George Arwin moved, you either followed or got left behind.

Boarding the Hogwarts Express the following week, Gemma waved at Remus then made her way over to him.

Remus was a good friend. He and Gemma had become unofficial study partners over the years, both preferring the solitude of the library to focus. Gemma always felt comfortable in his presence. Relaxed. Which she found somewhat amusing, given Remus was actually a werewolf. Or at least, she suspected he was. Over the last year or so Gemma had noticed a pattern in his frequent illnesses, and recognised the signs from some Defence Against the Dark Arts books she had read. She wasn't going to ask him about it though. He would tell her if and when he was ready.

Catching up briefly before Remus was called away on Prefect duties by Lily, who gave Gemma a quick hug hello, Gemma carried on down the train until she found an empty compartment. Tucking her trunk under the seat, she heard the sound of Alice and Mary catching up before she saw them.

"Gemma!" Mary cried as she barrelled towards her, pulling her in for a hug. "Oh it's so lovely to see you, and you look amazing! I love that top! Is it new?"

"Calm down, Mary. Let Gemma breathe." Alice said as she stepped into the compartment and gave Gemma a tight hug. She squeezed Alice tightly back. She had really missed her.

"It's so good to see you both." Gemma said. "And yes Mary, it is a new top. Thought I'd try something different." It wasn't anything special, but it was bright blue and a colour Gemma had never worn before.

"Well I love it!" Mary clapped her hands in excitement.

Gemma turned to Alice. "How was your birthday? Did you get my gift?"

Alice smiled and raised her wrist, a small silver chain dangling from it. "I did; thank you so much. And it was a lovely birthday, thanks. Always fun being abroad."

Alice briefly covered the highlights from her trip, before Mary started firing a thousand questions at them and somehow simultaneously also providing copious amounts of detail about her own break.

Mary loved to talk. Or gossip as Alice always states. But she was one of the kindest and sweetest people out there. Desperate to become a Healer and do genuine good in the world, Mary was a special kind of brave. In fact, just last year, a young Ravenclaw student had stumbled and hurt their ankle in front of some horrible Slytherins - Mulciber, Avery and Lestrange. Mary had rushed over to help the young girl, ignoring the vile comments and taunts from Mulciber. Mary held her head high as she helped the young girl to her feet and half carried her to the hospital wing.

"And I'm so jealous of Lily, of course, getting to work with Remus. He's the best of that group. I suppose I'd take Sirius, because hello, gorgeous, and gosh I'd even have James because at least I know he can perform every single spell out there. But Peter! I can't believe it. He's so quiet! It's weird! Like he's hiding something!"

Mary pouted, and Gemma and Alice slid a glance at each other, both trying hard not to laugh at Mary's outburst. It was a funny pairing. Peter was quiet, contemplative, often silently watching from afar. Mary was... not. No doubt Peter right now was just accepting his fate of having to spend the next year working with someone who would chew his ear off.

"Peter isn't a bad partner, Mary." Gemma said, trying to reassure her. "Besides, if he's just sitting back and listening while you do all the talking, then surely that's a dream come true. You do love talking."

Mary grinned. "That's true. And he is good at Herbology which I am rubbish at. So I can use him for that at least. Maybe I'm overreacting. It would be nice to have Sirius though and an excuse to stare at him all day. I caught sight of him on the platform earlier - somehow he looks even more gorgeous! Kelly Roe lives near him and she said she saw him out running almost every day over the summer. She said she was tempted to take up running herself! Although of course, she's already been there. A few times, I heard. I asked her about Jeff, as apparently they're back together, and she told me that Jeff could go… you know…" Mary chuckled. "So apparently they aren't back together."

Gemma and Alice slid each other a knowing look, then settled in for what would likely be a long, long train journey. They would catch up later, just the two of them, when everyone else had gone to bed.

Arriving at the Great Hall, Sirius took a moment to take it all in. The long wooden tables, filled with students chattering excitedly about their return. The fires blazing on either side of the room, filling the vast space with warmth. The subtle smell of dinner being cooked below them, not yet at the table but so, so close.

James nudged him forward, and he made his way over to where their fellow year six Gryffindor's sat. Two spaces were left, one beside Lily, the other beside Gemma. While tempted to annoy James by sitting next to Lily, he couldn't do it.

"James! Do you have to sit that close to me? There is so much space the other side of you." Lily was frowning hard as James practically threw himself onto her lap. Sirius chuckled under his breath. James would never cease.

"But Rogers isn't as cute as you!" James replied, nodding his head towards the fifth year behind him and giving her a cheeky grin. "How about a date Lily? Agree to one date, and I'll never ask you for a first date again."

Lily rolled her eyes. "Do you think I'm stupid, James? That I don't see what you did there?"

James pretended to not understand, then went back to begging Lily for a date. Sirius cringed a little, although somehow James got away with it, with most people thinking it was romantic that he was pining after Lily and doing everything he could to win her over. But Sirius wasn't so sure. He wouldn't beg anyone for anything. He'd learned that early on in life - if you wanted something, you had to go out and get it yourself.

"Do you think he'll ever give up?" Gemma was leaning into him, and the sudden scent of vanilla and oranges teased his nose. Was that a new perfume? A new shampoo? Did it matter?

"No." He answered honestly. "Do you think she'll ever give in?"

Gemma paused, considering her answer. "I'm not sure. Whether she'll admit it or not, she does actually like James. She respects him as a wizard, and she'll often laugh at his jokes – when he's not looking, of course. I think there is just a little too much baggage there at the moment. You know, with all that stuff with Snape last year and how James used to always be getting detention and screwing up class."

Sirius nodded in agreement, having never really considered all that before. He had just thought Lily found James annoying, but it was true that she did, on occasion, seem to find him funny. And yes, in their earlier years, he and James in particular had been disruptive, causing no end of issues for their classmates.

And then there was Snape. The thorn in their collective side. That incident last year when he and James had gotten a little carried away was not a good memory. And then Snape had called Lily a mudblood and started sniffing around Remus trying to catch him out. Well, all hell had broken loose. Sirius shook the thoughts away. He hated that time in his life. He wasn't proud of what had happened, and he knew James wasn't either.

At that moment, the Great Hall fell into silence as Professor Dumbledore, their Headmaster, stood up to address the room. Sirius leant forward, his arm on the table, listening to Dumbledore welcome the students back, welcome the first years, and begin the sorting ceremony.

He smiled, excited for the year and determined to make it a good one.