Disclaimer: I don't own the characters (except for a few OCs a created - most of them will be minor characters), spells, places etc mentioned, they are all JK Rowling's. This is JK Rowling's universe. I am not making any money out of this story.

Genre: drama, general, romance (pairings: James/Lily, Sirius/OC), with some humour and angst as well.

Author's note: Please let me know your thoughts, that would be really appreciated. Thank you! The title of the story is taken from the great HP-themed song by Ministry of Magic. I am taking part in the BBC Sherlock challenge on the Harry Potter Fanfiction Challenges forums.

Chapter 1

PURITAS

Join like-minded pureblood wizards and witches for an evening of discussions this Saturday at 8pm. If you are new and interested in joining us, wear your scarf bearing your house colours tomorrow, and we will come to you to give you the location of the meeting. Because of the nature of the issues at stake, we require that all details regarding Puritas shall be kept in absolute secrecy by everyone.

We look forward to seeing many of you tomorrow.

The dark-haired boy finished writing the twenty-fourth note with a sigh of relief. He pulled his Slytherin scarf tightly around his neck and smiled. This was all going according to plan.

"You've got to be kidding me," Lily muttered to herself.

Lily gave a great, world-weary sigh as she headed towards where Madam Pomfrey was standing. Here was James Potter, chatting with Madam Pomfrey as if they were life-long friends and looking like he owned the place.

"What are you doing here?"

Madam Pomfrey stared at Lily, undoubtedly shocked by her harsh tone. Lily had been helping out at the Hospital Wings since classes had resumed the month before, after the Christmas holidays. She wanted to be a Healer once school was finished and, even if she still had a year and a half left of it, she was so motivated that Professor McGonagall had spoken with Madam Pomfrey and they had arranged this. Lily being a Prefect and an outstanding student had of course played in her favour. Mostly she was there to observe, but she felt like it was a step in the right direction.

"I'm going to go fetch your potion," Madam Pomfrey said.

With another curious glance at Lily, Madam Pomfrey left. James cleared his throat.

"My dad had a bout of Dragon Pox that started in December," James said. "My mum and I've been taking this potion to prevent contagion. There's a long incubation period so I've got to take it once a week, for a few more weeks still."

"Sorry, I didn't know," Lily said quietly, looking down.

She felt a bit ashamed of herself. She had assumed James was there because he had hexed someone and it had gone horribly wrong, or because one of his pranks had had an unexpected effect and he had turned a first year into a parrot. She hadn't thought it could be something serious. She saw James as kind of a terribly irritating version of Superman.

"He's out of the woods now, so they say, but you never know at his age," James said.

Lily raised her eyebrows and James shrugged.

"He's turning seventy this year."

"Oh, I - I had no idea, I mean-"

"You mean you had no idea my dad was an old geezer," James said, grinning. "Don't worry, I get that a lot. They had me really late in life. My mum's two years younger than my dad, but she acts like she's fifty. She's very active. Thank Merlin she didn't catch it, but we've got to be really careful."

Now that she thought about it, Lily realised that James's level of annoyance had massively decreased since they had all come back from the Christmas holidays. Lately, when she got annoyed with James, it was either purely out of habit, or because he said something stupid while she was already grumpy, like in the early morning before she had her first coffee, or after receiving the odd dry letter from her sister. It was no longer because of him, not really. And she was starting to see that unfortunately, there were worse things and worse people than James Potter in this world. She actually missed the days when she believed that Potter was the enemy.

"Evans? Are you listening?"

James was frowning, like someone who isn't used to not being listened to, and doesn't understand what is happening. Lily realised she had been lost in thoughts while James was still talking. She winced apologetically. Madam Pomfrey had come back and given James the potion. Lily looked away as he drank it, feeling like she was intruding. She knew she was blushing, and thinking about it just made it worse, so she tried to concentrate on work as Madam Pomfrey gave her some explanations about the potion. After a while, James stood up, thanked Madam Pomfrey and turned to Lily with a smile so strange that Lily understood that he felt at least as embarrassed as she did.

"Thanks," James said earnestly to his shoes.

"Don't mention it, Potter," Lily said with a curt nod at James's shoes.

The shoes walked away, leaving Lily to ponder the new-found vulnerability of James Potter.

"Why don't your socks match?"

Sirius's hands stopped fiddling with the small glass bottle they were handling, but he didn't answer his friend's question. He did, however, give a perfunctory glance at his left foot — blue sock, and then at his right foot — white sock.

"Moony, can't you see I'm busy?"

Sirius returned his gaze to the cauldron below him, pouring the leech juice inside.

"Padfoot, you've been in a right state since Friday. If you hadn't been playing and rolling around with the wolf all night long, you wouldn't be so tired," James said, smirking.

"It's not my fault, the wolf wouldn't leave me alone," Sirius said exasperatedly, "it's like he just wanted me-"

Sirius trailed off abruptly, realising how that sounded. But it was too late; Peter and James were both hunched over in great gasps of laughter. Remus stood next to them, cheeks slightly flushed, the corners of his mouth fighting against a smile.

"Stop laughing, you morons," Sirius said. "I can't concentrate."

James stopped laughing suddenly. Peter took a look at James and then stopped, too. Sirius stifled a yawn. His grey eyes were bloodshot and he was blinking more often than usual. Only the thought of the prank kept him out of bed past midnight that night.

"I've just had a very disturbing, vivid image of Padfoot and the wolf, you know — together." James wrinkled his nose, looking from Sirius to Remus. "Now it's not so funny anymore."

"Gross," Peter commented.

"Can you please stop talk talking about that?" Remus said mildly. "I want to be able to look at Sirius in the eye again."

"And I want you all to be quiet so that I can get this done." Sirius brushed the hair out of his eyes with one hand, his other hand stirring the potion. "I'm flattered everyone's celebrating my masculinity as both human and dog, but we need to concentrate. Seventeen, eighteen, nineteen, twenty — here we go."

Sirius stopped stirring the potion and the four boys looked down at the liquid, its colour a strange shade of beige.

"Isn't it supposed to be light brown?" Peter said.

"Shut up, Wormtail," Sirius said. "And just wait a moment, will you. You trust me, right?"

Sirius's eyes met three blank faces.

"Don't take this the wrong way," Remus said. "But you don't want to hear the answer to that."

They managed to remain silent for a full five minutes, which was an achievement reserved for prank purposes. The potion's colour had got a bit darker and could now be considered light brown. Sirius tucked a strand of long black hair behind his ear and sniffed haughtily.

"See, light brown. If only you lot had a bit of faith in me. Moony, the vial?"

Remus passed a small vial to Sirius, who poured the potion into it with a satisfied and slightly devilish smile.

"Well done, Padfoot," James said, nodding.

"For the record, I would like to repeat that I did not agree with the choice of subject for this prank," Remus said.

Sirius groaned.

"Are you sure Spoilsport isn't your middle name?"

"That's enough," James said, quietly but firmly. "Is everyone clear on the delivery method?"

They all nodded and James pocketed the vial.

"Can't wait for tomorrow," James said with a dreamy smile, as the four boys started walking back towards Gryffindor Tower. "It's been a while we didn't play with old Snivellus. Padfoot, is the coast clear?"

Sirius took the Map out of his pocket and glanced at it. There were no dots in the Gryffindor common room; it appeared all the students were in their dormitories. No one was anywhere on the way to the common room, either.

"All clear," Sirius said.

They remained silent during the following few minutes, and they entered the Gryffindor common room just before one o'clock. In order not to attract attention, they kept both noise and light to a minimum. The only light came from the tip of Peter's wand. Peter being the clumsy one, he was usually the one carrying the light, the other three being able to walk around safely with the faint glow around them. However, it didn't mean there weren't the occasional slip-ups. Remus yelped in pain as he bumped in an armchair, which he believed was not at its usual place.

Remus bit his lip, holding his leg, "Damn armchair."

"Language, Moony," Sirius whispered.

Sirius's glee at being able to tell off Remus for swearing was obvious to the other three, even though they could not see his face properly in the dark.

"Accio parchment!"

Sirius jumped as the Marauders' Map flew from his hands and landed in the firm grip of Venusta Vance, who had been standing in the dark by the staircase leading to the girls' dormitories, her tall and athletic frame now visible in the dim glow of Peter's wand as he pointed it towards her. She lit up her wand to look at the parchment.

"What is this?" Venus whispered to herself, a curious smile lighting up her face as writing began to appear on the parchment.

Mr Moony, Wormtail, Padfoot and Prongs are proud to present THE MARAUDERS' MAP

Mr Prongs and Mr Moony send their warm regards

Venus stared at the words appearing on the parchment, torn between suspicion and awe at what the boys had apparently created. She wondered if it was a map of Hogwarts and its secret passages, which they seemed to know much better than she did. She really liked her female friends, but she had to admit that their risk-taking, or rather, risk-avoiding, approach of life at school was not always to her taste.

Mr Padfoot would like to invite Miss Vance to kindly sod off and take care of her business

"Give that back to me, Venusta," Sirius snarled.

Venus chose not to reply. Knowing her since they were children, he was perfectly aware of the fact that she didn't like her full name and preferred being called Venus. Which was exactly why Sirius often used her full name. Both of them were pure bloods and therefore somehow related, although they didn't even know which distant relatives they had in common. Venus's family did not have anything to do with the Blacks anyway. In the Vances' house, they were only mentioned as examples of a noble family that had turned out horribly wrong.

"Accio map!" Sirius said, raising his wand towards her. "What are you doing here in the middle of the night?"

There was a loud meowing, which made Peter jump slightly.

"I could ask you the same question!"

Venus looked outraged, but decided to answer anyway.

"I couldn't sleep, and then Shadow started pestering me to let her out so I came down here."

Shadow, Venus's black cat which she had got just before starting Hogwarts six years ago, had developed a fondness for Sirius early on, for reasons that escaped both her owner and the subject of her affections. Shadow trotted about to where Sirius was standing and started rubbing up against Sirius's legs, purring.

"And - how surprisingly," Venus said, "I find you four here. What the hell are you doing? Going to lose points for Gryffindor again? And what is this… is it a map of Hogwarts? How did you do it?"

"This is none of your business," Sirius snapped, trying to shoo the cat away.

"Oh, yes, Black, it is. Unfortunately, I happen to be in the same house as you. But if you do something — whatever, I'll go and wake Lily up, and we'll go straight to McGonagall tomorrow."

At the mention of Lily, James's eyes lit up.

"But we haven't done anything, have we?" James said innocently, speaking for the first time. "We were just taking a walk."

Venus glared at them suspiciously, knowing that they were up to something. But her fondness for James and Remus, and the fact that she secretly wished they would let her be a part of whatever they were doing prevented her from taking any action. The threat of telling on them was merely for Sirius's benefit.

"Go back to bed, Venusta," Sirius said. "You wouldn't want to be sleeping during class tomorrow, now would you?"

But Venus stood still, staring at them severely.

"I will do whatever I want. I will stay here until you go to bed."

"Wait, I recognise this," Sirius said, pointing an accusatory finger at Venus.

Venus was wearing a white and red hoodie with the English Quidditch team symbol, and Scott McCormack's name on the back. McCormack was the best Chaser in the world at the moment — if you listened to James and Venus, anyway. It looked suspiciously identical to the one James used to wear.

"Come on, Padfoot, it's not a big deal." James shrugged as Sirius scowled at him and made a face which was code for 'it's weird and you know it'. "She liked it and it got a bit too small for me so I gave it to her."

Sirius couldn't help wondering if Venus was wearing anything else underneath it. He immediately felt like slapping himself.

"Heavens be praised, little Jimmy's finally had his growth spurt," Venus said, smirking. "You're about my height now, well done you."

"A little bit taller," James said, wounded.

"You two are so weird," Sirius said, shaking his head.

"Just because you don't have the maturity required to be friends with a girl, doesn't mean no one else has," Venus said.

Sirius smiled smugly, spreading his arms.

"Maybe you haven't noticed, Vance, but being friends isn't what girls usually want with me."

"Because you're a pain in the arse, that's why," Venus muttered.

"If only they knew better," Remus said, exchanging a grin with James.

"Anyway, don't try and distract me," Venus said to the room at large. "I'm not leaving until you tell me what's going on."

"Look, if you promise not to tell, we can let you in on it," James said.

"I promise."

"By the way, I can't believe you didn't look at the Map again to double check no one was here," James said, shaking his head at Sirius.

"Tell her?" Sirius said, obviously choosing to ignore James's last words. "No way! Snivellus is ours, and ours only."

"She could provide a good distraction," James stage-whispered to Sirius. "You know, with her, erm, considerable assets."

James waggled his eyebrows and Peter tried but failed to stifle a giggle.

"James, are you referring to my breasts?" Venus said, scowling at James.

"Well, that depends on whether Snape is a tits or arse kind of bloke."

"Excuse me while I vomit," Sirius said.

Both Sirius and Venus actually looked like they had smelt something foul. Venus ran a hand through her long dark hair.

"James, stop being disgusting," Venus said.

"Sorry. But actually, we could really use your help, if you want. It's nothing really, you'd just have to say a couple of words to Snape and that's it, Peter will do the rest. And then in Transfiguration class, the fun will start."

"What are we doing tonight?" Sirius asked the next morning, his mouth full of food.

"I thought we could explore that tunnel we discovered last night, behind the Blind Wizard's statue," James replied excitedly.

"Oh, guys, couldn't we just rest for once? If we continue like that, you'll have to drag me you-know-where in a few weeks."

Remus kept his voice was low, as he was still afraid that someone would discover his secret. Thanks to James, most of his classmates believed he just had a problem with a badly behaved rabbit.

"Fine," James said, sighing. "We'll go without you."

"Hmm, we're forgetting something, Prongs," Sirius said. "Quidditch practice."

"Oh, right," James said. "By the way, I have to tell Venus about the new tactic I came up with."

"Couldn't you just tell her to go to hell and send us a postcard?" Sirius suggested hopefully.

"Sirius, she's the best Chaser in the team. After me, of course."

"I know," Sirius said, scowling.

Venus was one of the only girls in the school that didn't seem to be affected by his charm, and that just pissed him off. Which was ironic, since the other girls' attentions, when he did notice them, never kept him interested for very long.

"And try to be nicer to her," James said. "You know she's my friend."

Sirius growled and spilt some of his pumpkin juice on James's plate, but James didn't seem to mind as the object of his affection had just sat down a few seats away.

"Hi, Lily!" James said.

James had turned his full attention to her and, as usual when Lilly was around, his whole face had changed imperceptibly, becoming softer somehow. Lily was accompanied by her two Muggle-born friends from their year, Mary McDonald and Anna Ripperton.

"Oh, here are the twins," Lily said, scowling at James and Sirius. "Potter, just try to get through breakfast without doing anything stupid, won't you? I think you've lost enough points for Gryffindor for a lifetime."

James shrugged non-committally, not wanting to lie but not wishing to reveal the fact that they were going to pull a prank on Snape before leaving the Great Hall. For a few minutes, the boys sat in comfortable silence, enjoying their food.

At one point, Sirius noticed that Venus had come in and sat down a few seats away. Sirius thought about how annoying it was that Venus had interrupted them last night and had found out about the Map. On the other hand, he had to admit she was going to provide a very nice looking distraction indeed. She had beautiful wide almond shaped eyes hovering between green and yellow, which distracted the eye from her slightly long nose. Sirius's gaze travelled across Venus's face to her full and inviting mouth. He felt his pulse quicken as he suddenly wondered what it would be like to kiss her.

"I was wondering why you were so quiet this morning, but now I've got the answer," Remus whispered, leaning confidentially towards him.

Sirius startled; Remus was smiling kindly at him with just a hint of tease in his eyes. Sirius punched Remus lightly in the arm.

"No idea what you mean," Sirius said.

"Yeah, I would be surprised if you did," Remus said, laughing.

"You'd better stop this now, if you want to be OK for tonight. Why are so interested in Vance, anyway? Do you like her?" Sirius said, to try and direct the focus of the attention to Remus.

To Sirius's surprise, Remus blushed slightly. Remus looked around quickly to make sure no one outside their group was within earshot.

"It's not that I like her as such," Remus said. "It's just, well, you know — she's really beautiful."

"Foxy," Peter said.

Sirius snorted.

"Wormtail, no one says foxy since 1968."

"And she's really cool," James added.

"She is," Peter said.

"I mean, I'm not saying I like her in the way you mean," Remus said. "She's too much of a drama queen for me. And high maintenance. Not to mention that she's miles, if not light years, out of my league. But I can't say that she doesn't have any effect on me."

Sirius looked surprised.

"Really? What about you, Prongs?"

Sirius turned to his best friend, but he already knew there would be no support there. James shrugged.

"I wouldn't ever want to do anything with her, that would be too weird," James said, wrinkling his nose. "But I'd be lying if I said I haven't looked at her that way once or twice. Most of the time I don't even notice it, but she's hot, there's no other way to put it."

James laughed at Sirius's shocked face.

"Oh, come on, Padfoot, don't tell me you've never even thought about it."

Sirius leaned back in his chair and crossed his arms over his chest.

"Never in a million years."

James and Peter sniggered and started talking about the upcoming Quidditch match. But Remus was still staring at Sirius, an amused smile lingering on his face. Sometimes Remus's perspicacity was a gift and sometimes, it was the most infuriating thing in the world.

Once Venus had finished her breakfast, she caught James's eye across the Gryffindor table, and smiled. She was excited to take part to a Marauders prank, even if it was a small prank, and she had only a small role in it. As planned, Venus and Peter stood up. Peter held a glass of pumpkin juice in his hand. Venus made her way towards the Slytherin table, Peter on her heels. Snape was sitting by himself, a few seats away from a big group of loud fourth year boys. Venus took a deep breath and tried to ignore the wave of repulsion she felt the few times she had to speak to Severus Snape.

"Good morning, Severus," Venus said.

Venus felt very strange saying that name. They had never been on a first name basis. Having not seen her arrive and surprised at being addressed this way, Snape almost choked on his pastry.

"What do you want, Vance?"

Snape was frowning and squinting at her. Venus flashed him a smile, leaning against the table. She tossed her hair to the side and fluttered her eyelashes.

"I know you are amazingly good at Potions," Venus said. "And, well, I'm not that good, I could do with a bit of help. I was wondering if you would accept to help me?"

Snape's eyes were now only two black lines. His jaw was clenched and he glanced briefly behind Venus at the Gryffindor table.

"And what makes you think I would help you?" Snape said coldly.

Venus leant forward and placed a hand on Snape's arm, stroking it lightly, making sure Snape's eyes were on her.

"I think we could find an arrangement," Venus whispered.

Out of the corner of her eye, Venus saw Peter behind Snape, switching his glass with Snape's pumpkin juice glass on the table. Snape's face turned even whiter than it usually was.

"Leave me alone," Snape snapped, finally turning away from her.

Venus let go of Snape's arm and straightened up, with a shrug.

"You're missing out," Venus said. "Well, I'll see you later."

Venus could hardly contain her laughter as she walked out of the Great Hall. Nobody noticed Peter discarding Snape's glass at the end of the Slytherin table and then leaving. As Peter himself had said the night before, nobody usually noticed him much. The Transfiguration class started just a few minutes later. Professor McGonagall absolutely refused to let the Marauders sit together during her lessons, and every week she reshuffled the class's seating plan in order not to let them 'contaminate' always the same classmates. That week, the seat next to Sirius was assigned to Venus.

"You got lucky, you got the best looking one," Sirius said, winking, as she sat down next to him.

Venus sighed and crossed her arms over her chest.

"What? What have I said?" Sirius said.

"I always hear 'punch me in the face' when you're speaking, but it's usually subtext."

Venus then pretended to listen to McGonagall as their teacher started talking about another of the terrible consequences of human Transfiguration gone wrong. Venus tried not to look at Sirius. He looked very handsome indeed as he lounged back in his chair and did his best impression of an attentive student. She spent the first minutes of the class eagerly waiting for Snape to open his mouth.

"It should have taken effect by now," Sirius whispered to her, having noticed she kept glancing at Snape. "He just needs to start speaking."

"I never thought I'd ever look at Snape so many times on purpose. I feel like I need to wash my eyeballs now."

Venus wrinkled her nose in disgust and smiled as Sirius snorted. McGonagall stopped mid-sentence and turned towards them.

"Black, Vance, I am glad to see you two not arguing for once, but there will be no flirting either during my lessons, do you understand?"

All their classmates' heads turned towards Venus and Sirius. Venus was shocked both by the fact that someone though she and Sirius Black were actually flirting, and by hearing McGonagall say the word "flirting". Lily, who was sitting in the front row next to Peter, gave Venus a quizzical look.

"Yes, Professor," Venus said through gritted teeth. "Wasn't flirting anyway."

"Clear as a bell, Professor," Sirius said, and smiled brightly. "Absolutely sorry about the interruption."

McGonagall's stern frown faltered slightly.

"Yes, well. No more interruptions, or Black, you will just have to sit by yourself like an unruly six-year old."

A couple of minutes later, McGonagall finally asked the class a question for which Snape raised his hand to answer. Venus held her breath as McGonagall nodded at Snape for him to give his answer.

"You've gone potty because of the green carrot," Snape said.

There was a stunned silence. Snape's eyes widened and he shook his head. McGonagall scowled at him.

"I beg your pardon?" McGonagall said.

"I've gone up the roof, it's the mushy mushroom!"

Snape's voice got higher with every word and he was staring back at McGonagall, transfixed, and shaking his head frantically. James started laughing, soon followed by most students, even a couple of Slytherins.

"No, no! It's the baba — babo — baboon! The cute one with the haircut, crawling up my skin, eating Butterbeer with a melon. He can't do that, lalala, chicken poo!"

Snape had stood up and was wailing his arms about, looking like a mad man.

"Somebody take Mr Snape to the Hospital Wing right now," McGonagall said. "A Prefect? The only explanation I can think of is that Mr Snape drank some Babbling beverage, I am sure Madam Pomfrey will know how to stop its effects."

A Slytherin Prefect stood up and took Snape's arm and dragged him out of the classroom. Snape was still muttering gibberish under his breath and looked positively furious. Venus and Sirius, shaking with silent laughter, exchanged a look and gave each other a high five under the table.