Disclaimer – X-Men: Evolution and all characters therein are the property of KidsWB and Marvel Comics. This story is written for fun, not profit.

A/N – For Amicitia, who gave me a lovely banner. Incidentally, the book Ororo picks up quotes information from the paper given by Edward Lorenz to the New York Academy of Sciences in 1963. The title Vi reads out, however, is from his talk at the meeting of the American Association for the Advancement of Science in Washington D.C., in December 1972. There are no references to Aston Kutcher in this fic. Aside from that one.

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'Homeostasis' By Scribbler.

July 2004

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'Homeostasis: The ability and tendency of certain systems to maintain a relatively constant internal state of equilibrium in spite of changes in external conditions' – Oxford dictionary definition.

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Ororo was crying when Vi found her. The air of their little room was thick with something resembling regret. It pulsed in the doorway like a living entity and made her pause before entering.

"Blue-eyes?" She used the pet name concocted when 'Ororo' proved too difficult for a five year old to say.

No reply. Well, none worded. There were some sobs muffled by a pillow, but Vi didn't count those.

Midday sun crept through the door around her, scattering across the floor. The wooden boards felt hard beneath her feet. She was hot and sore from weaving baskets all morning, but she couldn't go in to rest. Not yet. Not with that... thickness blocking her way.

"Ororo, what's the matter?"

The little girl didn't look up. She seemed to curl in on herself – a loose smock topped with startling white hair, absent of face or feet or hands. She had her back to the door, and there was an open book next to her shoulder.

With a frustrated noise, Vi pushed through the thickness and sat on the bed. It bounced. "Don't be an idiot. Talk to me. It can't be anything I've done. I've been busy outside since I got up."

Ororo half-turned her face. It was chubby, with eyes far bluer than was normal for their tribe. They were made even more striking by their tear- sheen, the chocolate skin around them swollen. Vi might have thought she was having another episode, except that the weather had been fair and the Hungan sequestered sullenly behind his curtain since the last rainfall.

Any other sister might have reached out, touched and hugged – tried to soothe and coax an explanation.

But Vi was not like that. She regarded Ororo evenly; maybe even a little coolly, pressing the heels of her hands into the mattress.

The bed wasn't really that. It lacked the necessary frame. Back in Egypt they'd had a proper bed each, with goose-down pillows and silky-smooth sheets. Here there was a straw-stuffed ball on which they top-tailed, and netting that was supposed to keep the bloodsuckers out. They were outgrowing it now, but their hammocks would not be ready for a few weeks at best.

Finally, Ororo spoke. "Butterflies."

"Excuse me?"

"Butterflies." She turned over and felt out the book, which had been laid with spine screaming.

Vi recognised it immediately. "What are you doing with that? Did you go into my things?" There was a dangerous edge to her voice. The books she read weren't hers, but she guarded them like a mother jackal guards her cubs.

Defensiveness engraved the air. "It was on the floor. I didn't mean to read it; I just picked it up to put it back. But... I... oh!" Fresh tears sprang to Ororo's eyes. They spilled down her cheeks, and Vi snatched the book away lest they stain the pages, scanning the chapter title as she did so.

'Predictability: Does the Flap of a Butterfly's Wings in Brazil set off a Tornado in Texas?'

"Butterfly Effect," she said, parroting what she knew from reading and lessons in the blocky schoolroom the naive missionaries had built last year. They were all gone now, a mixture of waning interest and bad funding making gap-year students keep to their own shores. "It's a meteorological idea. Some people think that something as small as a butterfly flapping its wings can create a disturbance in the atmosphere that'll develop into something a lot bigger the further away it gets. Like a tornado."

She screwed up her face. It was not a notion that sat well with her. Vi searched for order in all things – maybe as a backlash against the upheavals that had frequently upset her nice, comfortable life. Like moving from Kenya to Cairo to Kenya again, with a light seasoning of dead parent. Butterfly Effect represented the very essence of chaos – unpredictability.

A choking noise drew her from her thoughts.

Ororo had stuffed a fist into her mouth and was biting her knuckles. Her right index finger was a little bloody, but she seemed not to care. She is too fixed on the insides of her eyeballs, staring but not seeing, her narrow chest rising and falling ever more rapidly.

"Blue-eyes...?"

"If that's what happens with something small," she said around her hand, "what happens with what I do?"

The words were difficult to decipher. Then, for a moment Vi was caught in a whirlwind of memory. Flash floods, inexplicable snow on the Serengeti, lightning from a clear sky. And in the middle, a small child with white hair, hands over her ears and crying softly.

In Cairo there were headaches, joint pains and other ailments. Skin so tender it hurt to blink, hurt to move, and soaring temperatures that preceded violent weather outbursts. Hailstone and snow and searing heat- waves. People had half expected hellfire and locusts to complement it all.

In Kenya the link between Ororo's illnesses and the meteorological phenomenon was made. Aunt Kakasha, Mama's sister, was an old woman who had seen many strange things in her life. She claimed to have once driven evil spirits from the body of her only son, Naburi – now a strapping man with a back as broad as an ox – using only herbs and a mummified fish. It was she who saw the patterns, the links and the trajectories in her new charges. It was she who knew that calming her strangely coloured young niece would bring peace from the storms that ravaged the fields, and that a full belly meant reprieve from severe drought where other villages had none.

Vi fought the knowledge that Ororo was different in anything but appearance. The white hair and blue eyes came from their mother and grandmother, who had possessed the same. Vi's plainness by comparison came from paternal genetics, as did her ill temper. She chased away boys in the marketplace that stopped to stare, and barked at stallholders who whispered 'goddess'.

There were no such things as gods. Her father, a photojournalist who worshipped science and technology, had taught her that before he died. And she made sure Ororo never succumbed to these flights of fancy. They were ridiculous – the stuff of fiction and folklore. And it was her job as big sister to protect her from gullible idiots.

But she couldn't deny everything. Not when specialists like Doctor Richards and Professor Xavier were writing papers on things called 'genetic abnormalities' and calling people to recognise the rise of the so-called 'X- gene'. True, these were nebulous American men, with nebulous American thoughts, writing in nebulous American universities; but some of the things Vi read about made sense.

Like Ororo, she had learned to read and speak English in Cairo at their father's insistence. As such, it was open season on the remaining schoolmarm's English books. Even the more complicated tomes, like the one now open on her lap. The one about meteorology that she had borrowed trying to better understand how one little girl could call clouds from an empty sky.

Knowledge was power.

But knowledge was also weakness.

"How many people have I hurt?" Ororo whispered with her newfound knowledge. "I do a lot of good for the village, sure, but it's not worth it if I... if what I do... Vi, I never meant for anyone to die."

Typical Ororo. At ten years of age, she had developed a flair for the overdramatic and habitually looked for a worst-case scenario. It made Vi set her jaw.

"It's only a theory," she said crisply. "There's no proof it actually exists."

"But what if it does?"

"Stop crying. You're being unreasonable."

Ororo dissolved into new paroxysms of weeping.

Vi felt a sudden twinge; an urge to squeeze her shoulder, take her hand, dry her eyes – to do something.

But it wasn't in her nature. She didn't know how to comfort that way. It was as alien to her as flight to a zebra.

So she stared impassively at the back of her sister's head, eventually ticking her eyes to the offending page, and then back again. One hand lifted, spread, wavered. Then her fingers curled, nails biting into skin made hard by toil, and it dropped onto the book with a smack. The taste of frustration settled on her tongue.

Vi had spent most of her life fighting with herself – trying to control herself and fit in with some pattern she could deal with. It made her quick- tempered, but it propped her up. Like, if little Blue-eyes fell, then it wasn't necessarily failing down, because she had someone to lean on; some order to her chaos.

Butterfly Theory. The very essence of chaos. Unproven and potent. It smelled bad, looked bad, tasted bad. Yet Ororo had swallowed it, and now it refused to be digested properly. It was stuck in her gullet.

Vi bunched her fists. Big sister to the rescue again.

Frustration made her balk. She didn't know how to placate from this, just as she didn't truly know how Ororo could do what she did. Books could talk about genetics and mutations and XX, XY, ABC, 123, but they couldn't answer the fundamental questions.

Vi was brighter than most average fifteen years olds. She nursed secret dreams of someday passing exams enough to go to university. One away from here, in a place she'd never been before. Which ruled out Cairo. Maybe Oxford or Cambridge, like Miss McDonnell, or one of the big American institutions. Something she could get a scholarship for.

Other girls saw as far as a good marriage and squalling babies. Vi was more concerned with Pythagoras and existentialism and Chaucer – nebulous schools of thought.

There was such a thing as being too nebulous.

She regarded Ororo with a perfect blend of indifference and determination. "Balance."

"What?"

"It's all about balance." She kneaded the mattress some more, choosing her words carefully. "Shut up crying for a second and close your eyes. Tell me what you can smell."

"But I - "

"Tell. Me. What. You. Can. Smell."

Ororo sniffed, but closed her eyes. Her chest juddered with leftover hiccoughs, but she gamely fenced them in, beginning slowly. "Dust. Straw. Floorboards – I mean, wood. You. Maybe some water?"

Vi nodded mechanically. There was a pail for Naburi's dog outside the hut. "That's all air. It's what you breathe. It's life. It's also a gigantic part of the world you live in. Without it, almost everything would cease to exist." A breeze wafted in, ruffling their hair. "Can you feel that?"

"Yes."

Probably better than I can, too. "You know the wind. It's change. And like change, it's inevitable."

"What's 'inevitable'?"

For a second Vi seethed. She was trying her best. Why did Ororo have to make this so difficult by interrupting and throwing off her flow? "It means unavoidable. Something that can't be prevented. You can't stop the wind from blowing any more than you can stop the dogs from pissing up the huts."

"Oh."

"The wind is change. It's the way of life. The most basic part. Breathe it in."

Ororo dutifully did so.

"Water is... is mystery. It's the unknown. You remember those pictures of the ocean I showed you?"

"Yes."

"Nobody really understands the ocean. It makes up most of the planet, but humans have barely scratched the surface of what goes on in it. Water is everything you don't... understand in life. Breathe it in."

Vi found herself acting on her own orders, filling her lungs with the vaguely metallic scent of filmy water. She heard Ororo's in-breath, a moment of pause, and then the out-breath. In and out. Ebb and flow.

I shouldn't be so theatrical, she thought, but went on regardless. It seemed to be working. "Wood is the immoveable. It's the unchanging part of life – that bit you can't influence and just have to accept, no matter what it is. There's no point in regretting it, because regret doesn't serve any purpose. The wood doesn't care if you regret, or feel happy, or even if you feel nothing at all. It'll still be wood. Breathe it in."

Another long, slow breath.

"Straw is... straw is..." She stopped. What was straw in this drama she was spinning? "Straw is the fire that keeps you warm when it's cold," she said at last. "It keeps animals away, and keeps you safe. But if you mistreat it, it'll burn you. Maybe even kill you. Straw is respect. Respect for nature, respect for the world around you, respect for... anything, really. Everything. Breathe it in."

Seconds passed. Vi waited for another bolt of inspiration to strike, to sew together what she was trying to say. Looking down, she pinched the bridge of her nose in the way that, had her eyes been open, Ororo would have recognised as her searching her vast storehouse of words for those that would hurt the least.

"And what are you?" Ororo asked suddenly, breaking the silence. Her husky murmur was like the deadened rasp of pebbles under a sea wave, or the slow movement of heavy stone on stone. The question was so innocent and vulnerable. It had trust in it.

And Vi... Vi sounded nothing but distant. Cold. A girl defending her own suspension of disbelief in the face of impossible odds. She hesitated, but only for a second. "I'm... I'm everything else. Everyone else. I'm the people you like, love, hate, and everything in between. And because of that, I'm the most important part. Without me, your life is nothing. Just senses. You can't live without people. There might be hurt and sadness and loss, but people will always need people. It's part of what makes them... people. If you can't breathe me, you're finished. Finito. Goodbye, and don't let the door hit you on the way out."

Ororo inhaled without prompting. She released it bit-by-bit, air rushing through the gap where her left canine was growing in. It whistled.

"These are the things that make up life. Your life. My life. Their lives." Vi gestured limply at the door. "You have to breathe them in order to survive. To exist. If you stop breathing, you die. If you stop breathing these things, you die inside. You understand?"

Ororo shook her head.

Vi thought for a second. "It's like... a triangle. It needs all three sides to stand up. Take one away, and the whole thing falls down. So if you take one of the things I just described away, then you'll be like that triangle. You'll fall down." Her hands found her kneecaps, pressing into them and rubbing in concentric circles. "It's all a question of balance. The world runs on a fine balance, and because you're a part of the world, you're also a part of it."

She half expected Ororo to say something about cliché-ing her way into clarity, but instead she opened her eyes. "But what does that have to do with - "

"If Butterfly Effect is real – and I'm not saying it is – then it's also a part of that balance. You make a breeze here, then that could make a tornado somewhere else. But what about the tornadoes that happen here? Is that because of some butterfly in Borneo?"

"I... maybe?"

"Maybe. Maybe not. It's all balance, Blue-eyes. You can't change that." Vi raised her open palm again and used it like a fan on her face. "I just blew down a house in the Ukraine." She raised her chin, letting the breeze from outside kick up her bangs, shifting them from her eyes. "That was a lizard blinking in the Galapagos Islands. I can't stop that lizard from blinking; I can only accept what happens when it does. So can the owners of that Ukrainian house."

"So you're saying that I shouldn't care about any innocent people I might have hurt whenever I use my powers? Is that it?" There was an unwelcome, vaguely accusing note to Ororo's words.

"No, I'm saying you can't take responsibility for everything that goes wrong in the world. If you feel guilty for a typhoon in Miami, who's going to feel guilty for the drought here? If you refuse to touch the rain clouds that are drowning the village's crops, would someone else feel guilty about getting good weather that makes theirs thrive? You ever think there may be other people in the world who can do what you do?"

A long pause. "Sometimes," Ororo admitted.

"And do you think they spend every second of every day wondering whether saving someone from a stampede by, I don't know, scaring the cows away with lightning – do you think that in that second, when it's life or death, they think about knocking down a house here because they accidentally messed up some minor meteorological conditions?"

"Meteo - "

"The weather, Ororo. Because they messed up the stuff that makes the weather."

"I... I guess not."

Vi sighed, sweeping hair from her face. "It's balance. You can't change what happens to them any more than they can change what happens to you. Whatever happens, happens. It was meant to happen. It'll be meant to happen whether you angst over it or not."

"So... you're saying it's like the wood?"

She paused. "Yeah. That's exactly what I'm saying. It's part of the equilibrium you've got to keep to stay alive and hang on to all your marbles. And if you ask me to explain what equilibrium means I will dump that bucket of water over your head."

Silence descended. Ororo appeared to be mulling over Vi's words. Vi kept her opinions to herself, but couldn't help thinking how perfectly dreadful her pep-talking was.

"I - " Ororo started, then gave a despairing cry and shoved her face back into her pillow.

Vi did nothing.

After a moment, she raised herself up again, this time using her elbows as props. She peered at her sister, blinking rapidly. Her breathing was smooth, easy, but hitched as if constantly starting words and then dropping them again.

Still, Vi did nothing.

"I don't want people to die."

A snort. "You think that crying into your pillow is going to stop that? Newsflash – death is pretty much a given. It's all just a question of how and when."

"What if the when is too soon because of... me?" Ororo asked softly. "What is the how is my fault?"

Vi shook her head. "What do you plan to do? Give up using your powers? You know what happens if you do that."

An image of crops razed to smoking stumps hung between them. Outbursts had been common at the beginning, when everything got too much and she just wanted to the world and her powers and other people to go away and leave her alone. Going cold turkey didn't work.

"You're making a mistake."

"Huh?"

Vi's hands were floating again. "Hating what you are – what you can do. Everything has a price." She smiled tightly, bitterly. "You'll learn that as you get older."

"I don't hate... I mean... I just..." Ororo fumbled.

"Please don't tell me I spent valuable brainpower on nothing. Didn't you understand what I just said about equilibrium? The world exists in balance. And balance demands acceptance – not denial, not conflict, and not tormenting yourself over something you can't change."

Ororo just looked at her with those big blue eyes, bottomless as the mysteries of the ocean.

"You'll just make it worse for yourself if you insist on angsting about this. And I'm all through with ideas for how to pull you from this... this idiocy." Vi slapped the book shut and rose to push it back into place with the rest of her school things.

She spent a long moment fingering the crisp spine of Professor Xavier's most recent work, and then turned with arms folded.

Ororo was staring at the back of her hand like it held the answer to the secrets of the universe. It took a cough to make her look up.

"You're my baby sister. I'm supposed to look after you. I don't care what Auntie Kakasha says about adoption papers; when you come down to it, it's just you and me, Blue-eyes." A tired breath slipped from Vi's lips. "But I can't protect you from yourself. And I can't protect you from stuff like this Butterfly Effect thing. There is stuff out there that's going to knock you for a loop, because you're... special." It hurt to say it. It hurt because in a relationship like theirs only one person could break the rules. And despite clinging to ordinariness, Vi ached to be that one. "You're special. More special than anyone here realises. So things are... different for you. And you're the only one who can deal with it. Nobody else can teach you how. You can choose to sit down and cry over every little thing, or you can pick yourself up and keep going as best you can."

She turned to walk away, but stopped and ran back again, picking up a small red book with embossed titles by some new author called Doctor Lenscherr. She didn't even look at Ororo when she walked out.

Naburi was outside. His skin was far darker than either Vi's or Ororo's, and his teeth shone like pearls when he smiled. She accompanied him while he filled another bucket at the pump and talked about what a good season they'd been having. Then she went to sit on the steps of the schoolhouse and read for the rest of the afternoon.

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FINIS.

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