Iroh was the only one on that cold, iron ship to truly see the battle, for he himself had a connection with the Spirits of old; but even in his eyes the picture of his nephew and his nephew's love was blurred and undefinable. Zuko was only visible for one fleeting moment, glaring straight ahead, his golden gaze flared and strengthened with the hidden power of Kagu. And then the fires in his veins erupted with such unimaginable passion and ferocity that for several days afterwards, he would lose his sight for no apparent reason and wander about in darkness.
Zuko and Katara had less than a second to prepare themselves for the onslaught of the monstrous, shadowed Avatar; but this short time seemed an eternity, a moment that slowed to a painful, agonized crawl. Zuko looked on Aang first in fear and uncertainty, but then the power of the sun inflamed him and he understood. The snarl of a deep, dark, ancient demon met his ears, and the faint blur of a savage shadow passed across the young boy's face. A cold evil struggled beneath his tattooed skin, leering and famished, threatening to devour his very soul and sanity.
Flame slipped between Zuko's bared teeth and his piercing golden eyes flashed to an unreal brightness. His knuckles snapped as he opened his hands and all colors of fire - white, red, orange, yellow, purple, blue - poured down the length of his bare arms, consuming the rough skin of his chest, his very eyes pouring blinding flame.
Katara looked on Aang and her bewildered gaze was pierced with the searing stab of a maddening, unbearable hatred as the Avatar's heart ripped and tore beneath the impossible depths of his rage. Injustice bled from the red rims of his dark-lit eyes, the guilt-poison seeping out of his shadowed frame as though his very life drained in red buckets from his veiled wounds. The conflict in him passed beyond any mortal recognition, anything that Katara could fathom; and then the deep waters overflowed within her, and she no longer thought as mortal.
Katara stood, her heavy coat and robe gone, her fingers dripping steadily with gentle droplets. Her dark hair glistened with ice crystals as a light frost caked against her soft skin and paled her to an elegant, angelic shade. The light blue of her eyes glowed like liquid-sapphire, a reflection of endless oceans, storming seas, the eerie twists and turns of ancient, undisturbed rivers.
Aang looked back at the two, and the demon in him recoiled like a repulsed snake. Zuko pulsed with warmth and strength and pure ferocity, the raw fury and brilliance of his renewed being overpowering the subtle darkness the Avatar bled. Katara dripped with the threat of unleashed floods, her gorgeous eyes glittering with a promise of peace that cut the evil in Aang more sharply than any mortal knife.
For one long, dreadful moment, the three stared at each other, no one daring, as yet, to move. Iroh stared at the sight, his eyes threatening to burn from their centers, but he did not look away.
Then the devil in Aang leapt, letting out one tortured, unearthly, ear-splitting roar.
Mountains shook beneath the sky. Seas roared, unbound, and flooded nations. Volcanoes exploded into hellish infernos. Wells in the deep surfaced like rampaging monsters. Earthquakes tore cities in half. Irresistible winds blew innocents into darkness. Everywhere catastrophe raged, tragedy ran rampant, terror fed like ravenous hounds. And beneath the dark sky in the North, Katara knelt upon the surface of the ocean.
She leapt forth and the water burst up beneath her in a running stair, her hands flooded, her body drenched and shimmering. Zuko appeared like a streak of lightning behind her and the darkness parted beneath his glorious blaze, suddenly revealing the hidden Avatar in the dark.
Katara fell upon him, casting away the strangling shadows on either side. Rivers ran through her fingers and streamed over Aang's head, down the shadowed length of his body, into his mouth and nose and ears and eyes. It swirled for a brief moment inside him, cornering the hatred and guilt and anger, a savage attempt to draw it out. But it rejected the glow of La's waters and spurted out of Aang's form, throwing Katara back on the hard deck of the broken ship.
The world thundered and changed beneath their warring and Zuko, infuriated, swept behind the young Avatar, his hands aflame and blinding; but Aang knew him, and he spun with a fluid and uncanny ease to meet his old foe and friend. Their hands met and they gripped each other with such unmeasurable force that deep down beneath the ice, the foundations of the earth cracked and a chasm formed in the sea.
Aang glared headlong at Zuko, his eyes so black and hideous it rivaled the curtain of absolute night that lingered at the edge of the stars, the cloak of shadow that dwelled somewhere in the furthest caves a thousand miles beneath the mines. He was screaming in unnatural tongues, his teeth blaring so white against the darkness of his eyes that they gleamed like rows of fresh-born stars. Zuko roared back against him as the flame poured from his mouth, a deep and deadly red that dripped like blood beneath his fang-like teeth, his golden eyes consumed with the fires of burning twin suns. Flame licked Aang's arms and for a moment, it seemed as though his pale skin had been burned and blackened beneath Zuko's intensity. The demon recoiled, as if to repent; and for half a second, the fire at Zuko's wrists faded and his grip loosened.
"LIAR."
Zuko's arm snapped behind him and he crashed hard onto the iron deck. The light in him died significantly and Iroh blinked, crawling to his nephew like a trembling child. Katara knelt down beside him only to be thrashed aside in the same manner, her gentle body tumbling loudly across to the other side of the ship.
"THERE IS NO MERCY."
Zhao had, all this time, been rent in agony and grief and fumbling to drown himself in the icy waters; but at the sound of the Avatar's words, his eardrums split, and he cried silently in agony beneath the din of the battle, the blood pouring from his ears.
Aang, picking up Zuko by his glowing throat, stared apathetically into the golden, flame-rimmed glittering eyes, his anger still pulsing but veiled. His grip tightened resolutely on his neck and Zuko's eyes grew wide, the light in him dimming to a feeble glow, threatening to extinguish. Then Katara cried out with a noise like heaven's trumpets and flashed towards the Avatar, a violent tidal wave of swirling ocean and daggered ice.
Aang could not respond quickly enough and fell to the ground, pinned against the iron with sharpened ice that pierced the thickened metal. He struggled against it, but the power pulsing in Katara's blood held him fast. Zuko, once again blinding in his power, leaned down towards him and put a hand on his forehead. The skin writhed and churned beneath the righteous fury of his fires, and in a deafening tone the Prince commanded the demon to depart.
A red flash sparked from his finger and glistened between them. Aang screamed, convulsed, and lay still.
Katara's arms relaxed and the daggers of ice melted, forming shallow puddles around the Avatar's still form. Zuko did not move, continuing to stare at the Aang's motionless body, his eyes sill dark, but empty.
Katara knelt down beside him and drew a long stream of water from her finger. She twisted it in the air before her, whispering something inaudible, forming the last few soothing words that would rid Aang of his cursed anger. Zuko watched her silently, betraying no emotion, his left hand placed solidly on Aang's shoulder.
Deep down beneath in the ground, the depths of hell trembled uncertainly.
"Return to the path of peace, Aang," said Katara gently. She closed her eyes and lowered the water to his parched and bleeding lips.
There was a sound like a chorus of demons as Aang's mouth opened, his eyes glowing with such indescribable hatred it passed all bearable explanation. With one furious hand he displaced Zuko and thrashed away the healing water. Then one arrowed, stone fist closed determinedly around Zuko's wrist as the other clamped upon Katara's throat.
Cataclysm enveloped the world. From one side, blue oceans, roaring seas, wise rivers flowed into Aang;s body. From the other, the unbound strength of the sun coursed into his heated veins. And both met in the center, in the middle of his fury, in the depth of his darkness. Aang stared out at the dark horizon as blood dripped down from his lips, a deep, black fire covering the last few inches of his body.
Katara's eyes were wide, unfocused, staring blankly as she scrabbled blindly at the front of Zuko's shirt. The air was bitter, whipping her face in mocking laughter and stinging her red-rimmed eyes, her lips chapped, her skin thrashed and dry.
"Don't cry Katara...it's going to be...alright..."
Zuko's teeth were chattering so hard he could barely manage the words from his throat. His arms held tight around her, embracing her from the winds with body and spirit, shielding her from the groping, clawed hands of her invisible monsters. His scar was stinging mercilessly but it didn't register in conscious thought; his mind was bent upon Katara, her terrified frame clutching to him desperately as she tried, in vain, to escape the reality of what had happened to them.
He could hear her chest heaving as she tried desperately to stop from hyperventilating, the tears falling from her eyes without her knowledge. He held her close and swallowed, though his throat was dry and sore; pulling her as close as humanly possible she buried her head into his chest and he gazed out into the freezing darkness, rocking her very slowly in his arms.
How could this happen?
Before them the ship was half-sunk in the ice, the darkness in the sky terrible and irreparable and complete. Off on the horizon, Zuko could see the slight glimmer of black flame and dark water erupting in screaming pillars. The earth rumbled briefly every now and then, the sky partial to short and brutal thunderstorms. And beneath the infinite blackness of the sky, upon the shaking instability of the ice, Katara leaned into Zuko's chest and whispered her love. And Zuko whispered it back, faint and unimportant though it all felt in the wake of this disaster.
And there they lingered, unable to recall the powers Roku had given them, the powers the Avatar had stolen. Insignificant they seemed, and small, and overlooked; two lovers crouched upon an iceberg, gazing out at the faint flashes of light a thousand miles away and whispering nonsense to each other in the dark. Just waiting.
It was the end.
Zuko knew it. Katara knew it. And beneath the weight of that knowledge they clung to each other, waiting, their eyes shut tight, the tears dripping silently from locked gazes.
They could not see man and woman who stood, unmoved, before them.
"It is not time for the end, my children. It is time to go back."