A/N: I've had this bunny in my head for a long time now, and I figured I ought to get it down before Korra kills it. I'm not going to spoil it for you, but I just always had a nice little idea about the 'Last Southern Waterbender'. Anyway, I love the whole prophecy idea, and the dragons still being alive and all that, so I'm just going to go for it. Hope you guys like it.

The Fire Sages had told a prophecy when Zuko was a child; that the current Avatar would ultimately be struck down in the Caldera, no matter when. He'd been a young Fire Nation prince, full of life and curiosity, and he'd been amazed that the sages could foresee such a thing. There had been other prophecies, given to the sages by the dragons.

Decades ago, in Sozin's time, the dragons had struck a deal with the Fire Nation, when the craze of hunting them had taken the land by storm. They would give the Fire Nation the wisdom of the spirits, and dragons to fight for them, so long as the Fire Lord declared it illegal to hunt them. He put each dragon under the protection of the Fire Nation military, and in turn, each soldier on his field under the protection of the dragons.

The dragons had foreseen that Lu Ten would be struck down in battle - and so Iroh hadn't sent his son to the frontline. Lu Ten was due to be married soon, too. And with an heir, Azulon had had no excuse not to put Iroh on the throne with his passing. Of course, most of these things were beyond young Zuko's comprehension at the time, but in hindsight, they all seemed so clear and simple.

The prophecies worked with the dragons speaking to the sages - and the sages alone - and the sages deciphering the riddle of their words into a prophecy that would eventually come true, unless counteracted, as had Lu Ten's demise been. They had foreseen amazing things; the victory in Omashu, against King Bumi, years before Zuko was of fighting age. With no Avatar to protect Omashu, it had crumbled at the Fire Nation's hands.

Zuko's favorite prophecy had to be the one about the Avatar being struck down in the Caldera; because it was the only one he'd actually understood. He had been nine years old when the news came that the Avatar had revealed himself in the Southern Hemisphere, a few miles outside a small Water Tribe village. The tribesmen had seen fit to escort the Avatar to their sister tribe in the North Pole, so he could learn Waterbending.

At that point, all the waterbenders at the South Pole had been exterminated already.

People - soldiers who came into contact with him - described the Avatar as a sixteen-year-old boy, bald with airbender tattoos, and partially trained already to bend water. The story went that the Avatar had been beginning his training a century ago, traveling to the South Pole to begin Waterbending training, when he'd hit a storm and been frozen in the icy seas. Word also got out that the Avatar was traveling on a flying bison.

When the Avatar reached the North Pole, troops moved there to exterminate the rest of the waterbenders for assisting him. The Avatar entered the Avatar state and wiped out many Fire Nation forces with the brutal strength of the ocean spirit. The troops insisted it would have been a victory if their dragons had been able to accompany them on the attack; as it was, the dragons could not survive in the cold temperatures of the poles.

The moon spirit, which had been destroyed by an Admiral Zhao, was restored, somehow, and Fire Nation troops fled from the north, by Firelord Iroh's order. The Avatar learnt to bend water. He moved to the earth kingdom to find an earthbending teacher.

He moved through the now colonized Omashu, only to be sent on by the troops there. He moved to GaoLing, where he moonlighted in underground bending championships while searching for a master. He found one - a Master Yu - and a rich family in the town arranged for him to stay with them while he mastered earthbending. Master Yu was old and stubborn, with crooked ways of teaching, but slowly, the Avatar stumbled upon his earthbending. He learnt to bend earth.

There was no way the Avatar could learn firebending, with the Fire Nation set on capturing him, so he moved toward Ba Sing Se to form an alliance with its king and army, to invade the Fire Nation on the day of black sun - information he'd stumbled upon while traveling in the earth kingdom with his water tribesmen companions.

Fire Nation troops by the hundred were sent to the earth kingdom in troves. They were to shed their red garb as soon as they reached the shores, disguise themselves as refugees and slip into the city of walls and secrets without notice. The secret troops came upon people in the earth kingdom who made fake passports, and the thousand-soldier-task-force slipped into the city, along with Prince Lu Ten himself, who had decided he would lead the attack on both Ba Sing Se and the Avatar.

Firelord Iroh forbade his son to enter the Earth Kingdom; for fear he might be struck down on the battlefield as his prophecy foretold. Lu Ten was stubborn and held his ground with the Firelord. The only thing Iroh could think to do was request his brother, Prince Ozai, travel with Lu Ten to ensure the victory, and the crown prince's survival. Ozai could not disobey his Firelord, and traveled with the crown prince to Ba Sing Se on the ship carrying the army's dragons.

The Avatar was severely outnumbered, not having been able to form an alliance between the Water Tribes and Earth Kingdom, and surrendered under the condition that the great city was left under the rule of its king. He was, however, not in a position to make demands or conditions, and was captured without struggle. The Earth Kingdom fell at the Fire Nation's feet. The Avatar was brought back to the Caldera in chains.

Iroh had seen fit to put Ozai in charge of the Avatar's imprisonment, provided it was humane.

Zuko and his sister had been taken to see the divine being upon its arrival in the Caldera. What Zuko had seen had been nothing short of disgusting.

He'd seen a young man bound so tightly from all points in the room that he could not even shift. The Avatar had been suspended from above and below and all around so that he hovered by the chains in the middle of the room. He was bound at the ankles, wrists, knees, elbows, neck and waist. A metal contraption was secured over the Avatar's head to keep him from seeing or speaking. He could only breathe through his nose. Zuko ran away and vomited.

Only days after this, he had done something remarkably stupid. Zuko called his father out on the Avatar's mistreatment.

"He's a human being, dad! Uncle Iroh would never have him chained up like that!" the boy insisted, his voice echoing in the hall way where he had found the older man. Zuko said something he shouldn't have. "This is why he's Firelord and you're not!" he has screamed at his father, vexed and angry and not wanting to see the Avatar suffer anymore.

First Ozai had backhanded the child, so hard Zuko had sprawled to the ground, staring up, confused. "You dare question my authority, boy?" the prince had seethed at his son. "Over the treatment of the enemy?"

Zuko had been caught terrified for a moment, and he just stared up, wishing he had said nothing. Ozai's stare pierced him, and slowly, Zuko moved into a kowtow and apologized for his behavior. He put it to childish idiocy and assured his father it wouldn't happen again.

"See that it doesn't."

And his father had left him in the corridor, kowtowing and hurt and scared and still angry.

Ursa disappeared not long after the boy and his father had this exchange. Zuko was crushed, and even angrier, blaming Ozai.

The Avatar lived in chains like that for four more years. Zuko didn't know for sure why they were keeping him alive, but put it to the fact that they didn't want to find the Avatar all over again. The Avatar would most likely be born to the Northern Water tribe in its next reincarnation; the only place the Fire Nation had been proven powerless against. Their city was a fortress, impenetrable and constant.

At least, this was the young firebender's assumption. He was thirteen now, older and wiser and too smart to spit words like that at his father. He was slowly grasping firebending, and if he had learnt anything from his bending master, it was never to challenge one you knew to be more powerful than yourself. Zuko could hold his own against a few of the more experienced benders in their ranks now, but definitely not to a general, and certainly not his father.

Zuko wondered when he had grown a need to be able to fight Ozai.

Still; he enjoyed sparring with his cousin, who would obviously go easy on the boy for the sake of entertainment, and the two grew to be like brothers. Azula went away to the Fire Nation Academy for Girls at age eleven. Zuko missed his mother more with Azula not being around, for some reason. Azula had been like a small part of Ursa left behind. At thirteen, Zuko was brought to see the Avatar again, this time by Lu Ten.

The Avatar was older, thinner; weaker now. His shaven head had grown messy hair to his shoulders, and his jaw had spurted an unkempt beard. He was fed once a day; the only time the head contraption came off, and he was spoon fed so as not to allow him to be unchained. Zuko stood and watched them feed the man, his face the picture of horror. Lu Ten's hand came down comfortingly on Zuko's shoulder.

"It's not something for a kid to see," the crown prince screwed up his face. "I'm sorry I brought you here."

Zuko waved his cousin off. "No. No, I needed to see this."

The Avatar's gray eyes searched, unfocused, while he was fed. He ate hungrily, but ran his eyes across his imprisonment as he did so. After four years, Zuko realized the Avatar was still hoping for a way to escape. Zuko felt his stomach clenching. The Avatar's wild gray eyes settled on the boy's terrified golden ones. The divine being had been supposed unable to speak, two years ago - but he spoke now, his voice a gritty whisper.

"Help me. Please."

Behind the wild, tangled hair on the airbender, Zuko saw a boy no older than himself, and he wanted to reach out and help him. He took a stumbling step backward as the soldier feeding the Avatar struggled to get the contraption on the now wriggling Avatar. The soldier punched the prisoner in the gut, and Zuko felt as though he too had been struck.

Lu Ten clutched Zuko's shoulders and led him away. "You didn't need to see that," he negated suddenly, as they walked. "That wasn't something you needed to see."

Zuko wanted Lu Ten to be right, but he knew in his heart he really had needed to see that, painful as it had been.

"Lu Ten," Zuko croaked as they walked. "What are we keeping him alive for?" he turned his eyes toward Lu Ten, worried.

Lu Ten sighed through his nose. "We're waiting for the sages to decipher the prophecy they received last year. The prophecy about the next Avatar," Lu Ten explained solemnly, his eyes shifting uncomfortably. "It's something your father thought up," Lu Ten furrowed his brow. "I don't … I don't know why my dad is going along with it."

"What about the next avatar?" Zuko suddenly blurted, stopping and turning to face Lu Ten, as his cousin had been walking behind him.

Lu Ten considered for a moment and then shook his head. "I shouldn't tell you. I shouldn't even know about it. Forget you heard anything, Zuko."

Zuko wanted to know more, but for his cousin's safety, he let it go.

Later that same year, Zuko stood up to his father again. This time, he snuck out of his room in the night to go to the Avatar, to see if there was anything he could do to ease the man's pain. He snuck into the Avatar's holding cell with a plate of food he'd stolen from the kitchen; real food, not prisoner slops. An Apple, and a moonpeach, and bread, and even some salty fireflakes. Zuko had assumed the Avatar was a vegetarian, though he'd probably eat anything now, but he brought no meat, not wanting to be rude.

The Avatar jerked to life at the sound of someone entering his cell. He couldn't speak, with the head contraption on, but Zuko could see he was breathing hard, scared. The boy wondered what his people had done to this man for the past four years to make him so scared.

"I- …" Zuko caught his breath and blinked at the Avatar in the darkness. "It's j-just me," he tried, hoping to sound reassuring, but only sounding like the fear that was shooting through him now. He was blatantly disobeying not only his father, but his Firelord too. He could be called a Fire Nation traitor for doing this. "My name is Zuko," he began, pulling his composure back.

He set the plate down on the only table surface in the cell; just near the door, and looked up to where the Avatar was suspended, wondering how he would get the food up to him. The Avatar was bound ten feet from the floor, and Zuko could probably grab onto his feet if he jumped. Zuko guessed he'd probably have more luck in climbing the chains - but he was sure that would hurt the poor man. He had come to help, not to hurt.

"I brought you some food. Real food," Zuko added awkwardly, and drew a breath in the darkened room. Zuko lit a flame in his palm to get more light, and reached for the wall torch to light it. The fire bloomed across it and light filled the room. Zuko could see whip marks on the Avatar now. Something had changed since he'd last saw the man.

Zuko supposed the first thing he should try to do was take the contraption off the Avatar's head, and he looked around and spotted a metal ladder leant up against the wall; he remembered how the soldier had fed the Avatar all those months ago, and he pulled the free-standing ladder toward the airbender. The Avatar sensed this new closeness, and breathed hard, like a komodo rhino that had spooked.

"Don't worry!" Zuko suddenly blurted. "I … I'm just taking off the helmet."

The Avatar froze as Zuko climbed the ladder and set about undoing the fastenings at the back of it. When it came away, the Avatar drew in a long, thankful breath through his mouth and his eyes did that crazy dance again. Zuko couldn't help but feel happy that he had helped. He climbed down the ladder, hopped the bottom three rungs of it, and then moved it around to the front of the Avatar.

He stood at the bottom of the ladder for a moment, staring up at the man, who was staring right back. He looked so pale. His cheeks were sunken, and his ribs showing. He looked like he would die any day now, if their soldiers didn't kill him first. Zuko felt sick in his stomach, and drew a breath, grabbing the plate and climbing the ladder one-handed.

When he reached the top of the ladder, he was so close to the Avatar he probably could've hugged him. The man stared at the boy, confused, and studying. Zuko blinked at him, and then took the apple from the plate in his hand, and extended it to the Avatar's mouth. "Here," Zuko offered, forcing a smile despite the churning in his gut.

The Avatar continued to stare at him, scrutinizing.

Zuko drew the apple back and looked at it. He looked to the Avatar again, and back to the apple, and then the young prince took a bite out of the apple, munching enthusiastically. "See? It's good. It's not poisoned or anything," he tried again, extending the apple again. He wanted to help. Zuko stared hopefully at the Avatar.

The man exhaled, and then took a bite of the apple Zuko extended, chewing slowly; probably because his teeth were so unused, after years of nothing but slop for nourishment. His next bite was hungrier, and the next hungrier still, and by the time the apple was finished, Zuko half thought the man hadn't eaten anything at all in years. And in a sense, that was true.

Zuko couldn't help but smile, as he took the piece of bread from the plate and extended it to the Avatar, who was now eating extremely enthusiastically. "So do you have a name?" Zuko asked hopefully, as the Avatar ate.

"Aang," the avatar replied between bites.

Zuko wanted to say more, but there wasn't much to say. The Avatar's name was Aang. That was really all there was. He supposed he'd have liked to know more about the Avatar's travels - Zuko himself had never left the Caldera except to go to Ember Island on vacation, years ago, when Ursa had been in the picture - and he was curious about them. But he didn't want to be rude; this man had suffered.

When the bread was gone, Zuko offered the moonpeach, and the Avatar scarfed it down ravenously. Zuko considered the fireflakes, but supposed they were a bit spicy. Then again, the man probably wouldn't mind. But, Zuko negated in his mind, he hadn't brought any water with him, in case the Avatar didn't like the fire flakes.

"Are those fireflakes?" the Avatar asked slowly.

Zuko swallowed, eyes flicking from the Avatar to the plate. He nodded quickly. "You like fireflakes?" the teenager asked, his brows coming down.

The Avatar allowed a weak smile onto his face and nodded as well. "I love fireflakes," he answered wanly, and gave a little wheezing kind of cough. Zuko held some flakes out to him, and the Avatar nuzzled into the boy's hand to take some in his mouth. He chewed, swallowed, and grinned despite all things.

Zuko watched, intrigued. The Avatar's unshaven chin tickled his hand when the older man ate from it, but he didn't mind.

When the flakes were gone, the Avatar tilted his head back and stared up. "Thank you," he breathed. "That was a nice last meal."

Zuko suddenly bolted in surprise. "What?" he hissed in shock. "What are you talking about?"

Aang chuckled - it was a dusty kind of noise, and it sounded like it could only come from Zuko's uncle - and dropped his head back to look at the boy. "I'm not going to live much longer - whether or not they execute me. I can only really control one thing right now," he explained, and Zuko didn't really understand, but he listened. "My resolve. I can resolve that I'm dying soon, and I can be sure I don't enter the Avatar state."

Zuko swallowed and nodded, thinking. "You …" he paused and thought for a moment, and then pulled a worried kind of face. He suddenly started searching his mind for ways to keep the Avatar alive; he needed, first, to get out of this cruel imprisonment. "Have you talked to the Firelord? Did they let you talk to him? Maybe you could-,"

Aang just shook his head. "No."

Zuko stared for a moment, and then frowned hard. Maybe if the Avatar escaped, he could live. This wasn't right; to be chained up here like this. Maybe he could get away and not die, thin and weak and helpless like this. Zuko felt ashamed of his people for allowing this to happen.

There was a clanking noise in the distance; and voices, panicked and furious and conversing. Zuko threw his gaze back toward the door, his eyes widening. He was caught. He turned back to Aang, and stared, horrified, almost looking for help - but the Avatar couldn't help him. Couldn't even help himself. Zuko felt his stomach knotting again, and he slid down the ladder, hoping to make a speedy escape before anyone found him here.

But it was too late.

The cell door screaked open and Zuko turned to stare, caught like a bird in a net. Ozai stood in the doorway, huffing like a wild animal, with the guards of the dungeon standing behind him, exchanging confused glances at young Zuko's presence in the cell. Fire consumed Zuko's vision and pain consumed his senses, and the next thing he knew, everything went black.

When Zuko woke up, most of his hair was gone; he was reminded of how bald the young Avatar had been when they first brought him to the Caldera. His face was bandaged over his left eye and he could feel a deep burn over it. His memory flooded back to him, and he remembered seeing his father attacking him. If Zuko had ever hated Ozai more in his life than right now, he'd be surprised.

He was on a bed, in his quarters - not locked a cell. But he was willing to bet he was locked in.

A letter was pinned to the wall he could see from the bed. He slowly got up, wavering on his feet, and then trod to the letter on the wall.

"Prince Zuko. You have been charged with the high treason of attempting to aid in the release of a Fire Nation prisoner of war. The prisoner you attempted to release the week before last has been relocated to a more secure prison, away from the palace, while we await word from the sages to determine when he can be executed. In the meanwhile, you will be locked into your quarters, tended to and fed thrice daily by a royal physician until your sentence is decided upon.

"Believe me when I tell you I sympathize with your intentions and injuries, but I cannot allow my subjects to free my prisoners.

"Yours sincerely, Firelord Iroh."

Zuko ran his unwrapped eye over the letter and this time, he felt too weak to even think about wanting to challenge his father. He could only see from one eye, and he was hungry, and he felt trapped. He wondered if this was what the Avatar felt like each day. No. Worse. Unable to see at all; unable to speak. Unable to breathe, except through his nose. Zuko immediately felt claustrophobic, and went to open the windows. Of course, the windows were locked.

He tumbled back to the bed and buried his face in the pillow. Pain seared across his eyes, but he ignored it.

Zuko waited to receive word of his punishment.