Disclaimer: ATLA and LOK and all characters therein are not mine.

A/N: What would be different, really, if Korra were Avatar during ATLA? Inquiring minds want to know!

Also, this whole story takes place during the first half, thereabouts, of ATLA 1's timeline (because Korra would get things done), but I shifted all the ATLA characters two years older because maturity and morality and empathy and, y'know, being interesting and vocabularies and things.

A Change in the Wind

I. And So It Begins

Long ago, the four nations lived together in harmony…

Then, everything changed when the Fire Nation attacked. Only the Avatar, master of all four elements, could stop them. But when the world needed him most, he vanished.

Eighty-three years passed, and the Fire Lord received a prophecy from his Sages, an omen divined from the spirits themselves: a new Avatar had been born, into the Water Tribe as was only expected, but the High Sage further predicted that this Avatar would first appear in the desolate wastes of the South Pole.

The Fire Lord perceived his chance for absolute dominion in this prophecy, and he swiftly ordered raids on all villages in the Southern Water Tribe, relentless raids that captured waterbender after waterbender and child after child to ensure the imprisonment of the Avatar.

But then Fire Lord Azulon died, and while all hoped for a reprieve, it was not to be so. The newly-crowned Fire Lord Ozai brought the High Sage, Shaolin, before him and had him executed for his apparently inaccurate prediction, and he demanded an alternative solution from those Sages remaining.

Terrified, the Sages suggested that the Southern Tribe could be hiding the Avatar still, choosing to endure the raids in the hope that the Fire Nation would lose interest before the end. Perhaps, they suggested, the punishments already exacted were not severe enough to elicit cooperation.

So, eight years ago—half a lifetime ago—the raiders killed all the waterbenders they found, young and old alike. They demonstrated no mercy, no compassion: children were torn from the arms of their parents, husbands from the arms of their wives. I was still so young, barely old enough to understand my nascent abilities, certainly incapable of understanding the threat inherent in their existence. I did not understand why the strange man was shouting at my mother; I did not understand why she sought to keep me out of sight; I did not understand why she lied.

But I understood fear, and I came to understand death as my mother fell, slain, in front of me. I came to understand that however long I cried for her to wake up, however long I shook her shoulder, nothing would ever be enough to bring her back to me.

I see her eyes in my dreams sometimes, glassy and blue and fixed on the sky.

And now I understand it all—she bore my punishment for me; she sacrificed herself for me. I am the last waterbender in the Southern Water Tribe, and I can do nothing with the life my mother saved. I could not defeat an entire nation single-handedly, even if I knew how to harness my powers.

Fire Lord Ozai has since focused his efforts on toppling the Earth Kingdom, convinced that he has abolished the Water-born Avatar and seeking to destroy that of Earth as well, all so he can force the cycle back to Fire, so that the Avatar can be raised as his servant, as his agent of absolute destruction.

But I believe the Water-born Avatar lives. In fact, I don't believe she was ever here in the South at all.

She's out there somewhere, gathering strength, and when she rises up, she will bear down upon the Fire Nation and its cruel lord with such ferocity that nothing shall remain standing in her wake. She will free the Four Lands, and I will finally have a measure of peace in my heart.

Until then, I will wait, and hope, and hide.

At the opposite end of the world, the Avatar slouched on a snow bank and listened to her reprimand with half an ear.

"Korra, what were you thinking?" Arnook, Chief of the Northern Water Tribe, demanded in exasperation. "Defiling the Spirit Oasis? This is sacred ground!"

She looked up at him, her sky-blue eyes flashing fire. "For one thing, I didn't defile anything, I bent it, which brings me to the second thing: you called it sacred ground—ground, Uncle! It's the only real ground anywhere in the North Pole! How do you expect me to master earthbending if I am not allowed to bend any earth?"

Arnook opened his mouth to reply but found himself at a momentary loss, and eventually, some of the iron left his stance as he covered his eyes with one hand. "Oh, Korra," he lamented, "whatever am I going to do with you?"

She bristled. "You don't have to do anything with me! You can let me leave!"

He lowered his fingers, appearing peripherally hurt by her words. "You truly feel so trapped here? But it is for your protection! The Fire Lord believes he has already killed you, and he searches elsewhere for another! Permitting you beyond the boundaries of the North Pole would be beyond foolhardy."

Her edges softened somewhat, and she cast her gaze away from her foster father's. "I know that," she conceded quietly. "But a year ago, on my sixteenth birthday, you told me I was special. You told me I was the Avatar. And you told me that I have a duty to this world—a duty that I would gladly carry out, and a world that's falling into chaos! But then you tell me that I cannot fulfill my destiny until I am the fully realized Avatar, until I have attained mastery of all four elements." She raised an impatient hand and began ticking off her fingers. "Sifu Pakku has lauded me as a waterbender; firebending is almost more natural than breathing to me; and I'm well beyond the basics in earthbending, despite the general lack of solid ground in this place! That leaves air, Uncle."

Arnook shook his head, an aimless sort of gesture. "The Air Nomads have been gone for a century; there has been no convenient revival since you learned you were Avatar. Even if you did leave the walls of this city, there would be nothing beyond them that would help you."

Korra got to her feet, her hand, now fisted, rising passionately. "But no one knows what happened to Avatar Aang, Uncle—the truth must be out there somewhere, somewhere that no one has looked. I can neither airbend nor connect with the Spirit World, so something must have gone wrong when I inherited the Avatar spirit; there must be some inconsistency, some obstruction, anything. If I could just be permitted to look for that—"

"No," he denied sharply, and his weathered face looked truly old, causing regret and guilt to stir in Korra's stomach. "You may be Avatar, but you are still a child, a child whom I swore to protect when I found you orphaned and alone. I will not abandon my responsibilities to you or to this tribe or, indeed, to this world just because you find my reasons lacking. You will obey me, Korra: you will stay in the North Pole for the foreseeable future."

For a moment, her fist clenched, and the desire to fight blazed brightly in her eyes. But then she surrendered to his will, bowing her head and meekly tapping her fists together in respectful salute, instead.

He exhaled and placed a bracing hand on her shoulder. "Your time will come, my child," he told her gently. "You are much too brilliant to conceal forever."

The Avatar accepted his words in silence, her gaze remaining downcast as his hand slipped away and the sound of his retreating footsteps disappeared from her ears. Slowly, a grin curled her lips, and she glanced back up.

"My time has come, Uncle."

It was the vernal equinox, the first of spring, when the sun and moon evenly split their rule of the heavens; a day of perfect balance, a day seemingly destined for the beginning of the Avatar's journey. But even with warmer weather impending, warmth was still relative in the North Pole, especially at night, and Korra shivered and exhaled little bits of flame as she stuffed supplies into several bags. Fastening them, she did a mental inventory: food, clothes, a blanket, some essential tools, a map…

"Map, map, where's the map," she muttered under her breath, tossing rejected items aside in her search. A corner of worn parchment peeked out from beneath a spare tunic, and she claimed it with a triumphant chuckle; unfurling it, she scanned its contents again. It would not be a difficult route—a straight shot south, as the sky bison flies—but it would be a long one, and she did not have a sky bison. Confined to the water of the Great Ocean, she would be forced to skirt the northwestern edge of the Earth Kingdom, slip south through the Western Air Channel, and then hug the Earth Kingdom's coast again as it curved back east so as to avoid sailing into the heart of Fire Nation waters. Once she had put the last curving tail of Fire's volcanic archipelago to her rudder, there would be nothing but open sea between her and the Southern Air Temple.

But she understood all that open sea might not be empty, as she had overheard her foster father's reports, which indicated that the Great Ocean was swarming with Fire Navy ships ferrying supplies and soldiers back and forth. It would prove no problem for her, though: she was an exceptional bender, and there was no need to run a blockade on the water's surface when she could simply sneak her small ship beneath it.

She rolled the parchment back and stuffed it into the haversack, leaving it sticking out the top, and she slung the pack onto her shoulders and stooped to retrieve the two other bags from the floor. As she straightened up, though, and raised her eyes to the door, she paused.

"Yue," she said, acknowledging the other girl's presence. "You're, er…up awfully late."

The princess took in the scene with a grave expression, and her unique hair was as white as the moonlight that spilled in around her shoulders. "You're leaving," she observed quietly, not making that statement a question.

Korra laughed weakly. "What tipped you off?" she said in a paltry attempt at humor, and then she sighed. "Look, I don't mean to upset Uncle, I really don't."

Yue failed to respond to that directly, her brow pinching. "I couldn't sleep. I was restless. I couldn't shake the feeling that I was about to lose something precious." She sadly met the Avatar's eyes. "You're my big sister; I do not wish to see you go."

The true enormity of her actions began to occur to Korra, and she fought against the tears that sought to burn her eyes as she left the only family and home she'd ever known. "You're fairly tolerable most of the time, too," she croaked, and several droplets spilled over her lashes as the princess captured her in a heartfelt embrace.

When Yue pulled away, there were shimmering trails streaking her cheeks as well. "But you do not belong to me or Father or even the Northern Water Tribe," she whispered. "You are the Avatar, and so you belong to the world."

Korra smiled crookedly. "Don't miss me too much, now; the world might send me back yet out of sheer exasperation."

The princess shook her head. "The world may be full of fools, but it is not so full of them as to reject you."

The older girl's brow furrowed. "…I can't really tell if that were a compliment or an insult, heh."

That got what Korra wanted: a grin flickered across Yue's lips. "In that case, I'll leave it up to you to decide."

The Avatar drew her back into a one-armed embrace. "Now that sounds like my baby sis," she teased lightly before she sobered. "Tell Uncle I'm sorry, okay?"

Yue nodded in acceptance of those terms, although she added, "He'll understand. He won't like it at first, but he'll understand. He only wants what's best for you."

"I know," she murmured, and her expression creased and her arm tightened, not willing to let go of this yet. "Walk with me to the harbor?"

Their boots crunched on the ice-crusted snow as they wound through the sleeping city; no one else was about at this late hour, and only the moonlight betrayed their presence, casting shadows on the snow. For having requested the other girl's presence, Korra struggled to ignore her, marching ahead purposefully and keeping her gaze trained on the immediate future, never daring to steal a glance behind. Even without the visual confirmation, though, she knew the princess was still there; Yue would never abandon her.

It seemed that the opposite did not hold true, and Korra grimaced, guilt lapping anew at her ankles.

The great white wall towered high above them as they reached the harbor, and Korra approached the boat that she had already chosen earlier that day; it was sleek craft, able to be crewed by a single person but still large enough to accommodate her supplies and the treachery of ocean waves. She tossed her bags inside and waterbent a hole in the ice wall, just large enough for her ship to pass through, and she gazed out that impromptu gate at the desolate horizon.

It would be a long and lonely journey to the Southern Air Temple.

She almost asked Yue to accompany her, but she bit back the words before they could escape past her teeth. Pragmatically, she hadn't packed enough food for two, and more to the point, she knew this voyage would prove to be as dangerous as it was reckless. She would not risk her surrogate sister's life for the sake of a little company.

Accepting this fate—a fate of her own design—Korra hopped in the ship, which rocked beneath her sudden weight. As she devoted her full attention to loosing the mooring rope and readying the single sail, she did not notice that Yue snuck a small object onboard, nestling it amongst the bags already settled in the stem. It was an artifact of their childhood: a stuffed koi fish doll. The two girls had spent long hours in the Oasis watching the spirits swim in their languid circles, and Yue's mother had fashioned them these toys—Korra's the black koi, Yue's the white. They had treated the dolls as talismans, believing with the innocence of children that a cherished object possessed protective powers.

Korra would need protecting now, Yue knew. Every little bit helped.

She tucked the white koi out of sight just as the Avatar completed her fussing, and she straightened up in the guise of someone who has done nothing worth remarking upon. Steeling herself, she smiled at her sister.

"May the spirits guide you on swift currents to safe harbor," she offered.

Korra returned the smile, or she tried to; her lips never really completed the curve. "I'll see you again. That's a promise. And you know I never break my promises."

Yue found that her throat was too thick, so she simply nodded and raised a hand, a final farewell.

The Avatar coaxed the waves around her vessel to carry her from the dock and out through the gate; once on the other side, she brought the ship to a halt, studied Yue one last time, and then pushed some of the ocean water up into the gap and froze it solid, leaving the wall seamless once more.

She stared at the blank ice for a long, uncertain time, and then she sailed away.