Disclaimer: I own nothing, obviously, otherwise I'd be super rich and chilling in my own private castle.

First year.
James and Sirius laughed and high-fived as Lily and Severus stormed out of their compartment.

"Oh, Merlin," Sirius said, "those two seem like a right pair - I look forward to spending the next seven years with them," he added, grimacing.

"I hope Snivellus gets put in Hufflepuff, that'd be hilarious," said James, grinning. "Snivellus… I won't be able to call him anything else, now; that was genius, mate."

Sirius smirked. "Yeah, well, when you grow up with my family, you have to be quick with the insults. Honestly, you should hear some of the stuff they come out with. I can't stand them. I'd better in be Gryffindor, I'm hoping the shock will give my mum a heart attack."

"Are they really that bad?" James asked, genuinely concerned. His own parents were kind, funny, and clever. He loved them with all his heart - especially his mother, who he couldn't imagine ever being without.

"Well, yeah - I said, didn't I, they're all Slytherins. The Great and Noble House of Black," he scoffed. "More like the Great and Noble House of Twats."

In spite of himself, James laughed. Before he could reply, the compartment door slid open again and two boys stood there, shifting awkwardly from foot to foot.

"Hello," the slightly taller boy began, "erm, could we please sit with you?"

"Oh yeah, of course," said James. "Are you first years, too, then?"

"Yes," the taller boy continued. Simultaneously, James and Sirius assessed his appearance. His robes appeared to be second-hand, judging by the faded colour and the straggly hem, and his light brown hair fell all over his face in an uneven cut. He looked slightly nervous, but was holding himself in a way that suggested he was trying his hardest to be confident. There was a long, thin, pale scar running from the end of his left eyebrow all the way down to his jaw. James made a conscious effort not to stare at it. "I'm Remus Lupin, and this is Peter Pettigrew."

As Remus moved further into the compartment to sit down, James and Sirius were able to get a good look at the other boy.

"Merlin on a broomstick, you're short, aren't you?" Sirius said to Peter, looking somewhat flabbergasted. James burst out laughing as Remus stifled a smile.

"Sirius, we've already made two enemies," James reminded him, still grinning. He turned to Peter and beamed at him. "Hello, Peter. Ignore him. His family haven't raised him right, but he's trying to grow out of it," he said, giving Sirius a quick nudge to the ribs.

Sirius tried to give Peter what he evidently thought was a charming smile. "Sorry, mate," he said, as Peter cowered away from him. "I'm just not used to seeing such tiny people."

"Er, it's okay," Peter squeaked as he edged his way into a seat.

"So, anyway, that's Sirius - as we've just established," James started. "Sirius Black, from the Great and Noble House of Twats -" here, Sirius gave a mocking bow, as Peter and Remus stared at him in bewilderment, "- and I'm James Potter, from the Great and Noble House of… er, well, haircare products."

"Potter?" Remus repeated, looking interested. "You wouldn't happen to be related to Fleamont Potter, would you? My mum loves Sleakeazy, she raves on about 'darling Fleamont Potter' all the time." As Remus finished talking, his eyes trailed up to James' messy, rumpled hair, and realised his mistake. This boy was clearly no relation of Fleamont Potter's.

"He's my dad, actually!" James said, as he raked a hand through his hair, making it, somehow, even more untidy.

"What?!" Sirius cried, a look of genuine bewilderment spread across his face. "Then what, in Merlin's good name, is wrong with your hair?!"

Peter cackled with laughter, the first time he'd looked anything other than petrified, and Remus chuckled heartily. James, however, looked offended. "I like it like this," he retorted, puffing out his chest. "I think it makes me look dashing and interesting."

"You're eleven," said Remus, amused. "There is nothing dashing or interesting about an eleven year old."

"You're eleven, too!" James huffed.

"Ah, but I never claimed to be dashing or interesting…" he replied sombrely, but adding a quick wink to show he was only teasing.

"I like you," Sirius said to Remus, beaming at him. "You're alright too, I suppose, Peter… Bit quiet, though, you're gonna have to make yourself known a bit more if you wanna be our friend."

Peter made another squeaking noise. "Friends?"

"Well, yeah," interjected James. "Or were you expecting to spend the next seven years sat on your own in the library?"

"Well, kind of…"

James slapped his palm to his forehead. "Mate, no! Right, come on, we've all got to be friends forever."

"What if we're not in the same House?" Sirius asked quickly. He tried to look as though he didn't care about which House he was Sorted into, although James easily saw through it.

Giving him an encouraging smile, James replied, "it doesn't matter. Does it?" he asked, suddenly turning to Remus and Peter who both gave small jumps then nodded enthusiastically. "See," he continued, giving Sirius another grin. "Besides, me and you are definitely gonna be in Gryffindor together, don't you worry about it. Are you two wanting Gryffindor as well?"

"Yeah, but I'd be happy with Ravenclaw," Remus said. At the same time, the other three boys noticed that Remus had a wide array of quills sticking out of pocket. James nodded in understanding, as Sirius coughed something that sounded suspiciously like 'swot.'

Remus, James and Sirius all turned to Peter for his response, only to find him shifting uncomfortably again. "You've got to stop doing that," Sirius told him in a tone that suggested he was trying to sound reasonable, "other you're going to get right on my nerves."

Peter instantly stopped squirming. "Er, well, erm, I think that, er, I probably won't get into, erm, Gryffindor, you know… erm… I'm a bit," he paused and looked as though he might start shuffling again, until Sirius gave him a stern glare. "Er, well, I'm a bit, I'm a bit shy, you know, so, er, maybe Hufflepuff?" He finished, sounding hopeful.

Remus and Sirius stared at him.

James, however, looking weirdly optimistic, cried, "nonsense! You'll be in Gryffindor with the rest of us, never fear!" and leaned over and promptly clapped him on the back. Peter made a shrill 'ahhh!' noise, sort of like a scream, and Sirius couldn't hold his laughter anymore.

"Aw, mate, you're a bit pathetic, I'll give you that," Sirius told Peter, still laughing. "You're alright though, good for a laugh - and you know what, I hope you are in Gryffindor with us, 'cos we'll be a good influence on you. Honestly, what sort of little loser aspires to be in Hufflepuff…"

Remus rolled his eyes but smiled and Peter grinned sheepishly. James looked incredibly confident, and grinned at his three new friends. "I think we're gonna be best mates," he announced, and, without any hesitation whatsoever, attempted to pull the three of them into a group hug, much to everyone's dismay.

"Alright, calm down, Beatrix Bloxam…" Sirius said, alarmed, as he attempted to wriggle free.

Remus burst out laughing. "I can imagine this is gonna be a long seven years," he said, muffled: his face was stuck in James' armpit. James, oblivious, simply patted Remus' head.

Second year.

"REMUS! WE KNOW!" James yelled. He sounded furious. He stomped towards Remus from one end of the corridor at an unnervingly fast pace, shoving other students out of his way as Sirius and Peter hurried behind him. Somehow, Sirius looked even more angry than James did, whilst Peter just looked… scared.

Oh no.

Remus blanched. They'd figured it out. They knew what he was. He turned to run, to try and get away, but it was too late - he took one step forward and felt a hand close in on the scruff of his neck.

Ashamed, frightened and upset, Remus allowed himself to be frogmarched by his three former best friends into an empty classroom. Once Sirius slammed the door shut, James rounded on Remus, and was surprised to find him in tears.

"I'm s-so sorry," Remus sobbed. It was the most miserable he'd ever been in his life. "I know I sh-should have t-told y-you, but I… I thought…" he stopped and moaned in grief. "I know that- that you won't w-want to be my f-f-f-friends anymore, but…" he couldn't continue. The tears fell thick and fast, and he sank to his knees. He knew he must have looked pathetic, and he knew they were probably staring at him in disgust, and he knew they were probably terrified of him anyway, and he knew that he was a monster… but he couldn't stop crying.

"What the- Remus, no!" Sirius said, shocked, as James and Peter both yelled, "NO!"

"Remus, you're our best friend!" James said.

"Yeah, we love you!"

"Merlin, Peter, no need for such emotion," Sirius winked. "Remus might think that this is an entirely different rendezvous to the one we've planned…"

James snorted as Peter spluttered out his defence.

"ANYWAY," James said, loudly, over Sirius and Peter's bickering, "Remus, why on Earth would you think that we wouldn't want to be your friend? Merlin, we just wanted to know why you didn't tell us straight away!"

At once, Remus ceased crying as Sirius and Peter snapped their mouths shut. All three f them stared at Remus expectantly. James offered him a small, but encouraging smile, and knelt down to Remus' level. "Look, mate," said James, softly. "We don't care. We don't. It doesn't change who you are. It just explains a lot of things, really."

Remus scoffed, and a fresh tear leaked down his face. "You don't care? YOU DON'T CARE? HOW CAN YOU NOT CARE? I'M- I'M A- I'm a monster…"

Sirius looked shocked. "No you're not! You're Remus Lupin! You're smart, and brave, and you're funny, and- and you put up with us all, even though we get in the way of your studying, and you're our best friend! And - I hate to say this, I really do - Peter was right. We do love you." Peter glared at Sirius, but nodded anyway.

"I love you all, too," Remus said, laughing shakily. James helped him to his feet, as Remus continued, "I'm sorry I didn't tell you about the- about my condition. I knew I couldn't keep lying to you all for long, I just didn't want to stop being friends with you," he admitted, looking crestfallen. James roared and immediately threw himself on Remus in what was supposed to be a hug but actually ended up being a tackle.

"James, mate, I don't know if you've noticed this yet, but every time you try to hug one - or all - of us, it ends painfully," Sirius commented dryly, eyeing up the two boys on the floor. Remus was clutching his head in agony whilst James still had his arms wrapped tightly around his neck.

James wasn't even paying attention, he was too busy crooning an old Quidditch chant into Remus' ear. "Remus, we love youuuu, Remus, we dooo! When we're apart, our hearts beat only for youuuuuuu!"

Some time later, when James had finally stopped serenading Remus, and Remus was looking more like his old self again, the boys stood up and all four of them looked at each other and slowly their faces spread out into identical, cheeky grins. "Look, mate," said Sirius, unusually grave. "We're friends forever, aren't we? We decided that the very first day we met. If we were going to start casting each other out of the group for reasons we can't help, you lot'd've kicked me out ages ago after you'd met my family."

Instantly, James, Peter and Remus shuddered as they remembered meeting Sirius' family for the first time.

"Anyway," said James, quickly changing the subject. "There's just one thing left to discuss."

"Oh, erm, well, it happened when I was fairly young, I don't really remember it-" Remus started, but James quelled him with a superior look.

"No, Remus, not that, mate. Don't worry, I'm not that insensitive."

Remus laughed as Sirius said, "don't lie, James, you're tongue'll go black."

"Will it?!" asked Peter, the colour draining from his face.

"No, you supreme tit-"

"ANYWAY," James interrupted loudly, glaring at them both. "THERE'S JUST ONE THING LEFT TO DISCUSS."

Sirius rolled his eyes but grinned. "And what would that be, then, mate?"

James turned to Remus, grinning widely. "What can we do to help you?"

Third year.

"Do you reckon Evans is ever gonna go out with me?" James asked, looking as hopeful as ever.

"No."

"Sirius!"

"What do you want to go out with Lily for, anyway?" asked Remus, genuinely bewildered. "We're only thirteen, that's much too young to be thinking about girl- OW, James!"

"Sorry," James replied, although he didn't look sorry at all. "Age doesn't matter when it comes to love, though, Remus. Lily and I are destined to be together."

"You sound like an idiot," Peter commented. "Anyway, James, will you pay attention, this is difficult."

The four boys were sat in the library and were already garnering glares from Madam Pince, despite them only being there less than fifteen minutes. After discovering Remus was a werewolf last year, the other three boys - well, mostly James and Sirius - had set to the task of finding a way to help him. After a year of research, they'd realised there was nothing they could do to stop Remus 'wolfing out,' as Sirius so lightly put it, so they'd changed course. James had come up with the idea of becoming Animagi, after seeing Professor McGonagall turn herself into a cat. Knowing the teachers wouldn't help them, the four boys had spent most evenings in the library reading books they weren't supposed to.

Peter groaned and slammed his head onto the table. "We're supposed to keep a mandrake leaf in our mouths for a whole month?" He mumbled into the wood. "That's gonna take me ages, knowing my luck I'll end up eating it…"

"Don't worry, mate," Sirius said. "We'll help you, even if I have to put a permanent sticking charm on your tongue."

"Don't do that," Peter said quickly, sitting up. "I'll be fine."

James wasn't paying attention. He was absentmindedly waving his wand in circles sending small clouds of pink hearts into the air. "Liiiiiiilyyyyy…" He whispered to himself. "Liiiiiiilyyyyyy…"

Remus eyed him warily. "James, stop it, you absolute git. You look like you're imagining wearing her skin."

"Mm, Lily's skin," James said, still whispering to himself. "It's like milk, isn't it?"

By now, it wasn't just Remus who looked alarmed. Sirius and Peter were staring at James with something akin to both shock and disgust on their faces.

"JAMES," Sirius shouted, slamming his fist into the table in a desperate attempt to wake him from his lovesick stupor.

"OUT!" Madam Pince yelled, seething. "OUT, OUT, OUT!"

The four boys ran from the library, stuffing parchments, quills and books into their bags.

"Every… single… day…" panted Peter, glaring at James.

"It wasn't my fault Sirius shouted at me!" James said, not out of breath at all.

"Yes it was, you were being a dolt again!" Sirius informed him. They all slowed to a jog, then, eventually a walk, out of kindness for Peter, who had gone very red-faced. Even Remus had pink cheeks.

"Anyway," James said, changing the subject.

"I feel like 'anyway' should be your catchphrase," muttered Remus.

"ANYWAY," James said again. "Carrying a mandrake leaf in our mouths for a whole month, eh? Shouldn't be too difficult, I reckon. Don't know how we're going to get all the stuff without getting caught, though."

"Oh, I don't know," Sirius said, sarcastically, "we couldn't use, say, I don't know, your INVISIBILITY CLOAK?"

"Oh, yeah," James said, grinning bashfully. "I suppose we'll have to rain Sughorn's cupboard and Pomfrey's greenhouses."

"Look," Remus began, "I really appreciate what you're all trying to do, but I really don't want you to get in trouble or- I mean, becoming Animagi without telling anyone is illegal, you know-"

"Shut up, Remus," Sirius said. "Also," he added, looking thoughtfully at James, "mandrakes are out of season right now, so it's probably gonna take us about six months before we're able to get everything."

"And then when we do have everything, it's gonna take us at least a year before we're able to transform… Which means we'll have just started fifth year," James said. He looked at Remus with worry. "Is that okay? Do you mind? I know it's a long time, but-"

Remus made an odd noise and red rose up his neck. Sirius balked. "Re, you're not getting emotional on us, are you?"

"Of c-course n-not," Remus stuttered, his eyes shining. "I just… I just really love you all!"

"Oh, for Merlin's sake," Sirius said, half-laughing, throwing an arm around Remus' shoulders. "Right, look, no more talk of your- of your-"

"Furry little problem?" James said, helpfully.

"Right, yeah, thanks, James - no more talk of your furry little problem. We've got bigger and better stuff to move onto for the time being."

"We do?" asked Peter. He had finally stopped panting and his face was less red, although he was still having to half-jog to keep up with them all. The other three boys had grown at least six inches over the last two years and yet Peter was as small as ever.

"We do," Sirius answered, smugly. "Okay, so we know that it's gonna take at least six months before we can start training, yeah?"

"Yeah," the other three boys chorused.

"So during that time, I propose we start a new project - just to keep us busy, of course," Sirius said mischievously, a cheeky glint winking in his eye. "I propose we create… The Marauder's Map!"

"Our map of what?" Peter asked blankly.

"Of the school!"

"Why on Earth would we do that?" asked James, just as baffled as Peter.

"Boys, boys, think of the possibilities!" Sirius practically yelled, dancing in front of the three of them and waggling his arms frantically in what he evidently thought was supposed to express his leadership and intelligence. "We create a map of Hogwarts which shows all the secret passageways, it shows us who's walking where - just think, we'll never be surprised by Filch again - and most importantly, it'll help us pull off pranks, and only we'll be able to read it!" Sirius gabbled excitedly.

Peter still looked blank. Remus looked apprehensive. However, realisation was slowly spreading over James' face.

"Merlin's underpants! Sirius, that's a genius idea!"

Sirius looked smug. "Of course it is. When have I ever steered you wrong?"

"Well, there was that time when you told me the giant squid wanted to be my friend," Peter said, "and it actually wanted to kill me."

"Well, I didn't know it was going to try strangle you, did I?" Sirius asked irritably, guiding his friends up to the common room. "But other than that-"

"There was also that time you told us we wouldn't get caught throwing dungbombs at Filch," Remus interjected.

"And the time you told me you'd take the fall if McGonagall caught us enchanting that chalk," James added, "but then you pretended to know nothing about it and I had to clean ink stains off desks for a week."

"This isn't like any of those times!" Sirius protested. "This one won't get anyone in detention! Or nearly killed," he added, give Peter a consoling pat on the had. "I promise, this can only end in good things."

James grinned. "Okay, I'm in."

Peter nodded nervously. "Promise I won't get strangled?"

"Promise, mon petit pal," Sirius said.

They all turned expectantly to Remus.

He sighed.

"Fine."

Fourth year.

Remus and James were in detention together. Remus was devoutly ignoring James. They were scrubbing out cauldrons in the Potions classroom using buckets of soapy water. Professor Slughorn had confiscated their wands for the hour, which Remus found incredibly unfair. He understood why James' wand had been taken, but surely Remus could be trusted to keep his?

"Look, Re," James tried again for the millionth time. "It could be worse! At least you're here with me! Think about Sirius and Peter having to clean up all that dung…"

"James Potter," said Remus stiffly, "I would kindly request that you do not speak to me for the next several days."

"Remus," whined James. After no answer, he huffed, "fine."

For the next five minutes, the boys worked in relative silence, before Remus heard James talking again.

"Hiya. No, it's not too bad, just scrubbing out the cauldrons - although dried lacewings are an absolute nightmare to get off, who'd have thought…"

"James," Remus snapped. "I thought I told you not to talk to me!"

James looked up, surprised. "I wasn't talking to you, Re, I was talking to Sirius, look." He held up a silver-trimmed mirror. Sirius grinned, waggled a hand at Remus and gave him a cheeky wink.

"Y'alright, mate."

Remus spluttered. "What is - how have you - JAMES POTTER," he roared. "SIRIUS BLACK. DO YOU HAVE ANY IDEA HOW MANY RULES YOU'RE BREAKING WITH THIS?"

Sirius and James beamed. "About six!" James said. "They didn't take us that long to make, to be honest, though, seems like quite a waste of a rebellion…"

"Anyway, Remus," Sirius cut in hurriedly, noticing the look of increasing annoyance on his friend's face. "I was just dropping in to say that I think Peter and I have come up with a way to finally complete the map."

The annoyance on Remus' face was quickly replaced with curiosity. "Oh, yeah? What do you think it needs?"

"Well, after extensive, labouring research," Sirius exaggerated, "I came across the Homonculous Charm - it'll make the map show everyone in Hogwarts!"

"Genius!" said James. Even Remus looked impressed.

"And Peter's had a pretty funny idea, too-" Sirius started.

"YES I HAVE!" Peter yelled suddenly, shoving Sirius out of the way so his face appeared on the mirror as well. "I think we should enchant it to insult Snivellus!"

James chuckled. "What do you mean?"

"Well," Peter began, looking very pleased with himself, "I think we should make it so that if Snivellus tries to read it, the parchment doesn't show the map, it just starts insulting him, calling him greasy and stuff like that-"

"Yes, yes, Peter," said Sirius, who had now shoved Peter out of the way and regained control of the mirror. "Obviously we'll need to come up with better insults than just 'greasy,' but overall, pretty funny, right?"

James and Remus agreed enthusiastically before they said their goodbyes and James shoved the mirror back into his robes.

"Are you my friend yet, Re?" James crooned, a soppy look covering his face.

"I will be if you stop making those eyes at me."

James beamed and enveloped Remus in a hug.

"James, mate, how many times do we have to tell you to stop hugging us all the time?"

"It doesn't matter, I still won't pay any attention to you all," James said, squeezing Remus even harder until they heard a rather definitive crack. "Oops. What was that?"

"You broke my chocolate!"

"Oh Merlin, sorry, Re, please forgive me again, I can't stand when you're cross with me-"

"James, STOP MAKING THOSE EYES AT ME!"

Fifth year. Present day, Platform 9 ¾.

"Morning, boys!" Sirius boomed, punching James and Remus on the shoulder each before lightly tapping Peter on the arm.

"Ouch, Sirius."

"Oh, stop rubbing your arm, Peter, I did it softly on purpose."

"Can you two stop bickering?" asked Remus. "Honestly, you two act like you've been married for thirty years - anyway, look, you're missing out on James…"

They turned to look at James, and found him blocking one of the doors to the train, trying to chat up Lily Evans. They couldn't quite hear what he was saying, but they knew it was something embarrassing because Lily looked truly aghast and James was flexing his non-existent muscles. Sirius groaned loudly. "Oh, James, mate…"

He was, however, interrupted by a very angry Lily, who had clearly had enough. "MOVE, POTTER!" She shoved him out of her way and stomped onto the train, Snape in tow.

James looked after her forlornly. "EVANS! JUST GO OUT WITH ME!"

The other three boys made their way over to the train, dragging their trunks behind them. "Come on, Jamesypoo," tried Sirius.

James looked mortified. "Don't call me that."

"But it's your name, Jamesypoo. Maybe you should give up on Evans."

"Never," he announced, striking a fist to his chest. Remus rolled his eyes but grinned at his friend's theatrical display. "I love her, and I swear to Merlin, I'll get her to love me back if it's that last thing I do!"

"This is going to be an incredibly long year," Remus muttered to Sirius and Peter.

A/N: So this is my first go at writing Marauder's fanfiction! I've tried to keep it as similar to JK's writing style as possible to make it more authentic.

Okay, so the rest of this fic is gonna follow them all throughout fifth year all the way through to 1981, and I'm gonna try and make it as long as humanly possible.

Also, if you're wondering about the "Beatrix Bloxam" comment Sirius made in their first year - she was a wizarding author who wrote fairytales for children that were famous for causing vomiting and nausea. Woo, chocolate frog card knowledge.

I hope you enjoyed the prologue, please please please review!