It proved difficult to pin Azula down in the busy revelry of the reception hall. Every time Katara or Zuko caught sight of her she would vanish into the crowd with a small, secretive smile and they would get sidelined by another courtier or noble wanting to speak with the Fire Lord.

The plum wine was beginning to make Katara feel soft, warm… the bright colours of everyone's robes and jewels would spin and blur at the edge of her vision as she moved from conversation to conversation.

Despite her misgivings about Azula, despite her anxiousness about the council's ultimatum to Zuko... she was having a really good time. Her friends were working the room and had even managed to get a few courtiers dancing with them, Ikem and Ursa were smiling and talking with a small group on the sofas, Iroh was happily engaging with a couple of the council members and kept giving her little winks of encouragement.

"Shall we dance then?" She asked with a coy smile. She wasn't unaware of the looks they were getting from the occasional older noble, but right now she felt invincible; she was on the arm of the boy she loved at a party in his family's honour.

"I do seem to recall a challenge being issued," He said in a low voice with a lopsided smile that sent shivers of anticipation up her spine.

"You think you can keep up?" She asked, pulling him towards the dancefloor where Sokka and Suki were circling each other in a slow fire waltz.

"In all honesty, I'm not actually very good," Zuko muttered, taking her hand in his.

Katara let him guide her in slow circles to the music. "It's fine, no one's putting on a show."

He snorted. "Aang is," Katara glanced over to where Aang was demonstrating a complex dance move, kicking his legs out and raising his arms with a grin.

"Yes," She acquiesced. "But I'm pretty sure no one wants to see their Fire Lord doing the prancing fire lily."

Aang finished the move with a little plume of fire into the air and Mina, on the sidelines and starry eyed, opened her mouth in an 'ooh'.

With a smile, Zuko tilted his head. "Point taken."

His hand swept over her ribs and settled on her hip, warmth soaked through the silk of her robe and into her skin. Katara tilted her chin downward and smiled up at him through her lashes, enjoying the thrill of this, being close to him in public.

It was nice. She could see he was enjoying it too; his eyes were light and he moved her across the floor with warm, sure hands. When the song ended, the room filled with polite applause and the dancers bowed to the band. Zuko's hand remained on Katara's hip for several moments, until the next song began and they had to leave the dancefloor.

"Time to do the rounds some more," Zuko said softly in Katara's ear, making the hairs on the back of her neck stand on end.

"Is it alright?" She asked. "Having me on your arm for an event like this?"

Zuko shrugged. "Like Uncle said, there's plenty of time for people to get used to it and besides," He glanced down at her with a smile. "I like having you with me."

"Fire Lord Zuko!" A thin, middle aged woman smiled as they approached. "And Master Katara, it's an honour," She bowed low, along with the man and woman beside her.

"Katara, this is Lady Wu, Lord Shin and Lady Fei," Zuko introduced and Katara bowed her head politely. She hadn't recognised Fei but there she was, glaring at Katara over her cup of wine.

"We were just speaking with Fire Lady Ursa," Wu said, voice smooth and velvety, not unlike Azula's in tone. "It is such a pleasure to have her back in the capital. The lovely Lady Azula, too."

Zuko smiled and turned to look towards his mother, smiling and relaxed in the corner. "It's good to have her back," He agreed. "It was a shame I had to leave during the Harvest Festival but…"

"Oh, everyone understands," Wu swatted a hand, shooting Lord Shin a quick smile. "Family is so important."

"Right…"

Shin drank slowly, glancing over to where Ursa and Ikem were. "Family is the most important thing," He agreed, turning back to Zuko with a sly glint in his eye. "The Royal Family should always lead by example."

"Of course," Zuko agreed, tensing slightly beneath Katara's hand- the only giveaway that he was anything less than comfortable with the conversation.

Katara squeezed his arm. "It must be a relief then," She said with a shallow smile. "To finally have a Fire Lord who prioritises family."

The three older courtiers exchanged a glance. "Of course."

"So good to see."

"A fine example for the Nation."

The bowed and made their way back into the crowd. Zuko relaxed slightly as they left, scanning the room with wary eyes. "They're like vipers in the grass sometimes."

"You sound like Iroh."

He scoffed but smiled at the comparison. "You can't clear the vipers from the grass, dear nephew," He muttered, feigning his uncle's voice. "The wise man uses the vipers to hunt the mice that feed on his crops."

Katara laughed. "What's that meant to mean?"

"I don't know, Uncle never makes any sense to me."

Their attention was caught by the crowd gathering near the band and they made their way over to see Aang demonstrating some 'classic' Fire Nation dance moves with Sokka and Suki. Katara caught Mai's eye across the room and smiled, shrugging.

"...Fucked her on a ship…"

What?

Katara turned at the sound of the voice, but it was lost in a sea of laughter and music. Her heart beat wildly in her ears and she tightened her hold on Zuko unconsciously.

"Katara?"

She turned back to him, shaking her head. "I thought I heard- never mind."

She tried to refocus on Aang's demonstration of airbending-assisted dancing. He threw his arms high and floated into the air, bobbing his head in time to the Tsungi horn.

"It's been going on since the war…"

"... Do you think that's why he defected?"

"Zuko."

He shook his head, the barest hint of movement. "I can hear them," They exchanged a look and Katara could feel furious tears welling behind her eyes. No. No. She wouldn't get upset about nasty gossip at court.

She knew it wasn't going to be easy, she knew she might face disapproval, she knew… but it had all been going so well. She'd been talking with so many people and hadn't really felt any animosity from them.

"Do we want a Fire Lord so easily swayed by a pretty girl spreading her legs?"

Zuko's head snapped around, his body temperature rising noticeably and Katara tightened her hold on him further, keeping him in place. "Don't."

His voice was a low growl. "You want to just let them get away with saying… that?"

"What good will causing a scene do?" She hissed, face flaming as the sound of vicious laughter undercut the general jovial mood of the crowd. "You'll just be… proving them right," She met his eyes, furious and disbelieving. "That I'm a bad influence."

He gave a short, curt nod and turned, trying to force a veneer of calm even as splashes of red crept up the back of his neck.

"He even wrote to her father about betrothal traditions in the South Pole…"

"Where do they come up with this stuff?" She scoffed quietly, but Zuko's face drained of colour. "Zuko?"

"Azula," He growled. He turned and pushed through the crowd, Katara hurrying to keep up with him. He stormed out onto the balcony overlooking the city, his whole body language screaming that he was furious.

A young couple making out in the shadows squeaked and hurried back into the reception hall, Katara quietly closed the double doors behind them, allowing Zuko a modicum of privacy and dulling the noise of the celebrations inside.

He was hunched over the balcony edge, little bursts of light the telltale sign that he was breathing fire with each ragged, heaving breath.

The lights of the Fire Nation's capital city twinkled cheerfully across the caldera and up the sides of the volcano, reaching up towards the glittering stars. The night sky in the Fire Nation was a swathe of pale starlight and deep, inky blue- less varied perhaps than the pinkish and green lights visible in the South Pole but beautiful in it's own way.

The contrast between the still starlight and the warm, ever flickering glow of the lanterns below made for a beautiful sight. If the mood were different it would be romantic.

"Azula's letters," Zuko breathed, lifting his head to look back at her, his crown catching the lamplight and flickering like a real flame. "No one's been writing to her."

"What?" Katara moved to sit beside him on the balustrade, the chill of the marble sinking through her robes. "How do you know?"

"Because the letter's aren't hers," Zuko glared back at the door. "They're ours."

She stared at him, dumbfounded, not comprehending. "What?" she shifted to face him, moonlight and candlelight catching pon the embroidery of her robes as she did so. "You think she's been intercepting our letters?"

"No," Zuko said softly, his anger simmering under the surface, still looking to the door. "When you found her in our rooms… that's what she took. Our letters."

An icy chill skittered up Katara's spine, despite the heavy silks of her dress. She remembered coming across Azula in their rooms, nothing obvious out of place… She'd not checked her personal desk for her private correspondence; she hadn't written any letters or received anything since then.

Her eyebrows furrowed. What would be of value to Azula in their personal letters?

Slowly, the whispered comments from the party begin to echo in her ear. Words and jibes she'd tried to dismiss as salacious gossip gaining a new, humiliating dimension with the implication that they'd been based on their letters to each other.

Suggestions that they'd been seeing each other in secret since the war, while true, could easily have been the result of gossip discussing how the two had been close since Zuko's time with the Avatar and his friends. That wasn't so suspicious… It was the references to more specific conversations they'd had, more personal experiences they'd shared...

The scandalised whisper about their first night together in his ship in the South Pole. Their first time.

That was the sort of memory that should be kept private, pristine. The idea that it was being discussed, mocked, tarnished by the gossip of court was humiliating beyond belief. Katara wanted to hide, cry, hit something… anything.

Zuko reached for her but she stood, turning her back on him. "I told you she was up to something, that she couldn't be trusted."

Was that her voice? It sounded so cold.

"Katara-"

"You didn't take me seriously," She continued, glaring out at the caldera. "You asked me to give her a chance and now she's- those letters are personal, Zuko. Not just letters between us but between me and my friends-!"

"I know," Zuko's voice was firm and the rustle of silks told her he had stood up but he didn't come any closer. "I do take you seriously, I know she's unpredictable-" Katara barked a humourless laugh and turned to face him, incredulous. "-but she's been getting better…"

"What's better for Azula?" Katara gestured to the closed door. "She's been planning this."

"I know, I know," Zuko swept his hands over his face. "I just… I- I don't…" He growled in frustration, unable to find the words. His eyes, so easy to read, were alight with fury but he was also somehow pleading, trying to reason on behalf of his sister. His sister who had proven once again that she could not be trusted. "You don't understand- she wasn't always like this…"

"But she's like this now," How couldn't he see? "Even if she is getting better. I know you're angry too."

She couldn't understand why he wasn't demanding Azula be locked up… Was it just to avoid a scene?

He glared at her. "I'm angry, Katara," He turned back to the edge of the balcony and she could see the trembling of his shoulders, barely keeping himself in check. "I'm so angry at her; all I want to do is go back in there and challenge her to an Agni Kai. Is that what you want me to do?"

Agni Kai, those two words were a slap to the face. The last Agni Kai had left him with a deep, burned and bloody hold in his chest. She felt sick.

"Obviously not," She bit out, anger thrumming in her veins. She was so angry she was instinctively reaching for any water she could find, cooling the air without deliberate intent. "But there are courses of action in between doing nothing and declaring an Agni Kai, Zuko!"

"And I'm trying them," He was blazing, alight with emotion. "I would have thought you'd understand- didn't you say you'd never turn your back on people who need you? Well, Azula needs me."

Katara felt the fight drain from her, leaving her body slumped, defeated, exhausted. "I don't think she wants you, Zuko."

His scowl deepened and he drew himself to full height, with all the authority of the leader of a nation. He opened his mouth to respond but the door to the feast crashed open. Their heads snapped round to see a soldier, panting and wide-eyed. Behind her, the sound of the party had swelled and become discordant, somehow.

"Fire Lord Zuko!" The soldier cried and Katara recognised Kei, the soldier from Zuko's old crew. "Master Katara! There's been an incident… Prin-Lady Azula- she-!"

"It's Kiyi!" Sokka called, pushing through the crowd. "Katara- you need to heal her!"

Katara looked to Zuko, whose face had drained of all colour.

Barely enough time for her heartbeat to stutter at the look of dawning horror on his face and Zuko charged into the chaos of the hall. With a wide eyed glance to Sokka, Katara followed.

The reception hall was a mess of people hurrying around and crying out in alarm as they charged through, pushing bodies aside in an attempt to hurry to the Family Wing. "Zuko! Katara!" Aang called and scooted overhead, eyes wide in fear. "Come on!"

The ground beneath them shifted and Katara grabbed for Zuko's hand as a large tile broke away and propelled them forward, through a mass of shocked nobles stumbling out of the way. Zuko's hand was clammy and slipped from her grasp as they reached the door to the Family Wing of the palace and the soldiers ushered them through, slamming the doors closed behind them.

"Where are the others?" Katara gasped as they ran through the corridors, Kei leading the way. Sokka and Aang exchanged a look but Toph spoke with confidence.

"The girls are staying back, they're going to keep the fancy-pants nobles from freaking out. The grownups are with Kiyi."

She could hear screams. Piercing, sobbing cries of pain echoing through the corridors. They all broke into a full sprint at the sound.

"What happened?"

"We don't know for sure…" Aang started but Sokka interrupted him.

"Azula burned her."

I told you so. Katara thought, despite herself. She didn't say it, she couldn't say it… but she was pretty sure Zuko heard it anyway. She reached for his hand again but it was just out of her reach.

Zuko's heart was breaking and there was nothing she could do about it.

There was a small crowd of servants and soldiers outside Kiyi's room, muttering to each other in low voices that rumbled beneath the cries from inside. Tears streaked a few faces and they parted with respectful bows as Zuko pushed through into his sister's room.

Kiyi's twisting, kicking legs were visible behind Ursa's hunched over body, trying to repeat soothing platitudes to the small child writhing in pain on the bed. Katara's nostrils filled with the pungent smell of burned flesh, too eye-wateringly familiar to be mistaken for anything else.

And Kiyi's screams, piercing, breathless and pained were like an icy dagger to the heart. Katara's eyes were spilling over with tears even as she rushed to Ursa's side. "I need water!" She cried, meeting Ursa's stricken, tearful eyes briefly before turning to the other occupants of the room.

"Here," Katara turned to see Lai carrying a large bowl of water. "I've sent for more water as well."

"Thank you," Katara lifted some of the water from the bowl and turned back to the screaming child in Ursa's arms. "Can you keep her still?" Katara asked, feeling sick.

Ursa sobbed, moving her hands to hold Kiyi down by the shoulders, her grip shifting from comfort to restraint. Ikem crouched by his daughter's side, tears spilling silently down his face as he helped hold Kiyi still. His forehead met Ursa's and they glared into each other's eyes with anguished resolve.

Now Katara could see Kiyi properly, and her breath caught at the sight of the bloodies, blackened wound across the girl's face. The left side.

Zuko crumpled beside her, kneeling to the floor and reaching for the little girl's hand, which grasped onto his as her cries intensified. "I'm sorry, Kiyi," He wept into the bedding. "I'm so sorry."

"It'll be okay," Katara kept her voice low and even, trying to soothe as she brought water-gloved hands to Kiyi's face. "It'll be okay."

The palace nanny appeared with another large bowl of water, whispering panicked, fevered apologies that went unheeded by anyone but Iroh, who gently steered her away, out to the hallway with hushed, soothing words. "Let us give them some privacy," He said, ushering the concerned attendants and friends out of the room before closing the door behind him.

Kiyi's screams transitioned into breathless, heaving sobs. Her unburned skin was red and blotchy, and her tiny body was beginning to shake from shock. "She needs to be kept warm," Lai said, bringing a blanket to cover the child. Katara hadn't realised she was still in the room but the older woman's businesslike professionalism was a welcome reprieve.

It seemed to calm the others a little, too. Ursa helped to tuck the blanket around Kiyi as Ikem and Zuko kept her as still as possible.

Katara tried to focus on working the water into Kiyi's face, repairing torn muscle and reconnecting tissues beneath the pale glow of her hands. It was hard; the girl kept twitching and trying to get away.

It was messy and so much harder than healing any of the war-wounded had been. Kiyi had never suffered before, not really, and she'd never known the touch of fire. She was a cornered baby animal, just trying to get away from her pain and unable to do so.

Katara shifted tact and tried to focus on pain relief, working to numb the nerves the way Yugoda had shown her last time she was in the North Pole, thanking the spirits for the older woman's wisdom as Kiyi began to quieten, no longer trying to escape her family's hold or Katara's healing hands.

But Katara knew she wouldn't be able to fully heal the mark in one session. The burn was deep, deliberate. Kiyi's eye was badly damaged and that would require a complete session on its own. The burn had certainly been intended to maim, to disable the child, possibly even kill her.

Why?

Why?

What on earth was wrong with Azula?