A/N: This is my first Harry Potter fanfiction... I hope I do reasonably well. LOL.

Disclaimer: Nope, nothing's mine. I wish I owned Sirius and Remus, though. Sigh.

Rating: PG-13 for some (mild) language.

Pairings: James/Lily because they're so much fun, and slight Remus/Sirius slash ,because they're the ones I can make more chaos with. LOL. There's nothing explicit at any point in any case, though. LOL.

Genre: Humor/Romance

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

''Theory of Chaos: The flutter of a butterfly's wings can cause a hurricane at the other side of the world.''

Sirius titled his head to the side as he mused about this statement he'd just read in one of those muggle books. He was sitting in his Transformations class, bored like hell. So he'd thought that poking his head into his friend's bag would make up for the boredom of a young Professor McGonagall's lesson. As if he hadn't known how to transform into something else for years...

''Like that book? Keep it... philosophy is for muggles like this is lesson to us. Plain boring.'' Selena Syren told her friend, sitting at the same desk as her. Sirius shook his head and kept reading with a slight smile. If the teacher managed to see him, Selena would work a distraction long enough so that he could wake up from his state of trance.

Sirius used to say that you couldn't judge people for the house they were in... and that was because Selena happened to be a Hufflepuff. It was strange that on the first year they'd sat together because they'd been grounded by Dumbledore to sit apart from everyone else (it had been due to Sirius inventing the name 'Snivellius' and Selena roaring with laughter), and since then they decided to sit together to keep each other posted on what happened in the different houses.

Selena didn't use to sit with the Marauders too much... but she wouldn't be the object of their fun either: James knew she'd get back at him at some point. But enough about Sirius' friend: this was about his plan.

''Sel, do you believe these theories? Your parents are muggle, what do they say about them?'' Sirius asked, reading over and over his favorite one: Chaos theory.

''Some people do.'' Selena shrugged. ''Why do you ask?''

''I just want to check if it works...'' Sirius said with a mischievous smile.

- - - - -

''And here comes the hot stepper.'' James grinned as Sirius appeared down the corridor. ''Did you mess up with McGonagalls's head this time? Or did she get back at you for last week?''

Sirius almost flinched... but he'd found that funny. Sirius, with his easy good looks and killer movement (that catwalk made girls and boys stare as if in a trance) had been the center of attention for years. And the previous week he'd made a bet against James: McGonagall's knickers would be pink. James had said white. So they'd set up an Blower (when set under someone it started a wind that could lift people, if strong enough) and so they found out that they were...green.

So, none of them had won, but they'd had a good laugh. The problem was when Dumbledore found them and decided to call their parents. (Oooops...) But it had been well worth it anyway!

''Nah, just thinking about something I read.'' Sirius shrugged. ''Do you believe in the Theory of Chaos?'' James had a really dumb face for a second that meant 'What the fuck are you going on about?'. So Sirius tried to explain. '' Muggles have many philosophies, one is that a small act can cause big damage.''

''Dude, that's Murphy's Law.'' James corrected.

''Ehm... yeah. Only this Chaos one is older. I guess Murphy's is Chaos Version 2.0 Extended or something...'' Agreed Sirius. ''But I want to know if it's true, and I need to do something really cool that could prove it is.''

''You could try it on him.'' James happily said, pointing at someone who walked with them towards their next lesson. At first Sirius thought James was speaking about Remus Lupin, who walked towards them too... And when Sirius was about to defend him, he saw who James had been seeing instead: Lucius Malfoy.

So glamorous and hateful, with that silver-ish hair that everyone seemed to adore... at least the Slytherin girls. He appeared surrounded by his friends –more like, servants and adorers. And of course, where would people like him be without someone to make cruel fun of? It was obvious he'd pick on Lupin.

Before Malfoy could open his mouth, James had already gotten in between the snob and the werewolf, pretending he'd been there all along. It was better to be safe than sorry, and since Sirius seemed ready to morph into a dog and bite Lucius' leg off, it was better to spare everyone lots of trouble.

''He still doesn't know that we're the big hits here.'' James hissed to Sirius as Malfoy said something mean about them to his friends. ''Do you think we should shave his hair off?''

''That's about the best idea you've had in the whole year.'' Sirius told him as Remus reached them too. ''Hey, what's up?''

''The ceiling.'' Remus answered quickly. Sirius faked a grin. That would have been his usual answer, but somehow now Lupin had adopted it too. James laughed at the look on their friends' faces, and they entered the classroom. ''I think I forgot to do my homework.''

''It would be the first time in your life.'' James said.

''I didn't even remember there was any homework!'' Sirius complained.

''It wouldn't be the first time in your life.'' Remus snapped.

''Hey, you too... there's just SO much fun at my expense. Have I pissed you off in a way that's more than usual?'' Sirius whined as they sat down together on a table. Peter Pettigrew was already there too, saving them the best seats, at the back of the class. ''Hey, Wormtail.''

Peter nodded and James informed him about Sirius' last idea and about Malfoy's new soon-to-be hairstyle. Lupin seemed to be busy looking for something in his bag... he was always busy. Or at least, doing something. Sirius never had any serious work to do... or at least hardly any he would care about. Sirius poked Remus.

''Pay attention to me!'' He demanded. ''I just discovered this Theory of Chaos that we could use on Malfoy... Well, forget about that. How did you end walking down the corridors alone?'' It was just SO Sirius to do that, Remus thought. He got quite paranoid and possessive when he was alone (and defenseless, as he used to say- ignoring the fact that he was a werewolf and could hold his own, but...).

''He was with his group and I was his rival. The Marauders always have problems with him, it was no surprise. I was just unlucky.''

''So it was logical he'd pick on you.'' Sirius gritted his teeth as he said this.

''Logic is a systematic way to reach a wrong conclusion with confidence.'' Remus said, and his friend recognized the quote. He had a rather stunned face, and Remus smiled widely. ''I gave you the book with Murphy's Laws, so you're not the only one who knows them.''

''Go suck a lemon.''

And thus, the life of the Marauders passed.

But there was a clear thought on Sirius' mind: If the slightest thing could become something huge, he wanted to know what consequences his actions would have on other people indirectly. It was just too big a chance to lose... the school year was almost over. So he better rushed to pay Malfoy back for all these years!

- - - - -

Please throw all trash in the bin and leave a review on your way out! :) Thank you!