A/N So this chapter is slightly shorter than the others. Mostly because the next one is a particularly important one. This focuses more on the spiritual side of things, but we are getting to some action, so those of you who like a bit of drama rest assured you will get your fill! Would also like to thank my kind reviewers - keep them coming, always happy to receive any comments!

Update: for some reason the last section to this chapter didn't copy! It is pretty important though :S hope you can all read it!

The Cycle of Sun and Moon

The moon disappeared over the horizon as the sun started to ascend. The soft grey-blue light of dawn seeped through the streets of the caldera and pooled in the royal palace gardens. Zuko rose and stretched, pulling on his loose training trousers and a sleeveless black shirt. Drawing his curtains open, he glanced down at the gardens. He had chosen a different suite from that the Fire Prince traditionally occupied - remodelling it of course - but the important thing was that he could look out at the gardens, at the flowers that flourished in the sunlight and the insects that buzzed around, revelling in the sweet scents. And most importantly, he could see the pond where he and his mother would feed the turtle-ducks in the shade of the great willow. He had seen too much of destruction, he wanted to be reminded every day of the life that surrounded him.

Now he noticed something different about his gardens. There was a figure sitting on the grass in the sun in a half-lotus position. Her back was to him and her brown wavy locks blew around her back on the soft breeze. He smiled to himself, and hurried down to join her. He didn't usually meditate outside, but perhaps it would do him good. If this is what the fire sages had taught her, he would gladly learn more about his element.

As he walked silently over the grass to meet her, he heard her voice being carried to him on the wind.

"Good morning Zuko. Have you come to join me in meditation?" She had not moved at all but somehow she knew he was there.

"Yes," he replied simply, and sat down next to her, took a deep breath of the damp early morning air, and submerged himself in meditation.

They both seemed to come out of their thoughts the moment the morning sun touched their faces. Zuko hadn't felt so alive in a long time; without seeing the sun, without feeling its heat on his skin, he had focussed on its energy below the horizon. He had felt how the slowly growing heat was infiltrating his world, how the light awoke a new sliver of heat in the garden, how the plants responded to the wake up call of the sky. He had only started considering all these thoughts, when the immense power of the sun hit him full in the face. The immediate surge of energy he felt at the sun's presence was amplified tenfold by his state; he had opened himself so much that the thrill of the sun snapped him back to his own body and roused him from his mediation. He glanced over to where Katara sat and noticed that she too was blinking in the sunlight.

Catching her eye he saw her smile serenely, just like she used to on their travels. He noticed how it lit up her face and once again loved the fact that she was wearing red.

"Well, Sifu Sparky, shall we get started?" she asked quietly, so that she did not disrupt the calm of the garden. Zuko smiled.

"Right, since you can already produce a flame and I'm pretty sure you can handle control, I'm going to teach you the fireball. You need to spread your legs like this," Zuko instructed, keeping his legs wide and bending down into the stance, "and keep one hand at all times by your side, level with your stomach, ready to be used. The other will go from the same position on your other side to fully extended while you twist your torso to give it power," he demonstrated sending a small fireball from his fist.

They were practicing in the covered arena. Zuko had it built especially for his frequent practices. Initially, he had used the outdoor arena but could not stand the constant quips of the spectators - usually some of the older counsellors that he suspected still had sympathies for the war. This arena was still large enough so that he could practice all his moves without destroying anything, and it was made of metal so that it wouldn't burn. Air vents lining the top of the walls kept it cool and it could only be entered through one door so that he knew who was watching. Life at the palace was hardly private, and this was the one place that was completely his own. And now he could train Katara in there since he knew nobody would see what was going on.

On her fifth try, Katara produced a sliver of flame and shot it away from her body. Zuko frowned and told her to stay still. He circled her, correcting her stance - lifting her arm so it was completely perpendicular to her body, shifting her other arm closer to her torso, straightening her back, pushing down on her shoulders so she would squat lower. He did not notice Katara's uncomfortable flinching at the contact.

"Try again. But this time, put force into it. The fire comes from your centre - let it become hot and then feel it travel up your arm to pool at your fists. At that point - and only at that point - you can let it go." After a few more tries, Katara finally realised what she should be feeling and corrected her own stance to allow the fire to seep through her body. The results were still pitiful.

In frustration, she closed her eyes and remembered the power of the sun when it caressed her face during her meditation. It had stirred something in her core; let her feel a power that only the full moon had ever induced in her before. Focussing on that sensation, she let it pool inside her until it was coursing through her veins, until her whole being was heat.

Zuko watched as Katara became more and more frustrated with herself. She closed her eyes, he thought, to calm herself down. However, he started sensing more and more heat emanating from her body. Without opening her eyes, she went through the move he had taught her - but this time with an energy he hadn't seen in her before. It wasn't gentle and flowing like she was used to with water - like she had been trying to handle fire so far - it was sharp and exact, her arm whipping out and stopping at the right distance. A ball of flame, one that consumed almost the whole width of the room, erupted from her fist and shot towards the other end, hitting it and turning the metal walls a glowing red. There was the usual creaking from the metal expanding, but he knew that it would cool down soon enough.

Zuko turned to regard the water bender who had just created a fireball. She was immobile in her final position, eyes still closed and breathing heavily.

"Tell me that worked," she said quietly.

"Open your eyes and have a look at the wall opposite you," he replied, a chuckle in his voice.

Katara did so and was pleased to see the red wall the opposite end of the arena. She relaxed her stance and grinned at the Prince, who was standing, arms crossed, just behind her.

"You used the sun, didn't you?" he asked, raising his good eyebrow questioningly.

"Yes. I felt it here," she replied, indicating her stomach. "It is really hot," she added, frowning.

Zuko rolled his eyes.

"We are playing with fire Katara, I'm not exactly sure what you were expecting! This is why we usually train shirtless." With that, he removed his black, sleeveless shirt and tossed it behind him, as he thought of what to teach her next.

Katara couldn't help but notice his toned body. Sure, she had seen it before, and she had always admired it from a distance, but now it seemed to strike a chord within her somewhere deep down. She felt the urge to run her fingers over it and lightly trace the contours of his muscles. He lifted his arm to scratch his head in thought, absent mindedly running his fingers through his long, black hair. She watched the muscles in his arm and down the side of his torso flex with his movement, and noticed how his scruffy black hair framed his pensive face. Her eyes fell on the scar from Azula's lightening on his chest and she scowled. She could heal so much better now; if the incident had happened with her current knowledge, there would be no blemish on his perfect skin.

"I'm sorry," she said softly, not removing her eyes from the scar. Zuko blinked out of his thoughts and looked, confused, at Katara. He noticed she was staring at the scar on his chest, not looking happy. He suddenly felt ridiculously self-conscious and resented the fact that her expression was somewhat disgusted when she looked at him. Sure, he was used to people being disgusted by the sight of him, but it still hurt. And somehow, it hurt even more because this was Katara looking at him like that - Katara, the only one that hadn't been repulsed enough by the scar on his face to avoid touching it. The good half go his face burned red with embarrassment and annoyance, and he clenched his fists by his side, digging his nails into the palm of his hands to stop himself from snapping at her and leaving the arena. No, he needed to be able to deal with this.

To his surprise, she walked towards him instead of stepping away, and she placed one dark hand on the scar. He flinched at the contact, but then relaxed into the touch. Her hand was warm, and he was reminded of the sensations of her healing him after the lightening strike. She shifted her gaze up to his eyes, her anger clear in their blue depths. He noticed that she had grown quite a bit taller and now stood only slightly shorter than him, her nose reaching about the height of his lips.

"I'm so sorry Zuko, you shouldn't have taken that lightening for me. And I should have been able to heal you better. Please forgive me?" her eyes softened at the request and he detected no falsehood in her steady gaze. He was also very aware at how close she was to him. Relief spread through his body - she was angry at herself! She was disgusted with herself! Without thinking, he placed his hand on top of hers.

"There is nothing to forgive. The world couldn't lose you. And neither could I. I regret nothing Katara," he murmured softly, losing himself in her eyes. They stood immobile for a time - neither quite knew how long - until Katara flinched. Some thought had entered her head, he reasoned when looking back at the moment, because without warning she disentangled her hand from his and demanded they continue their lesson.

Zuko was puzzled but decided to let it go. The place where her hand had rested remained oddly cold for the rest of the session.

When it was time for him to wash up and start the day's paperwork Katara followed him out, revelling in the fresh breeze. He excused himself and started towards his rooms.

"Tonight," called Katara from behind him.

"Pardon?"

"We start your lessons tonight. It has to be tonight so be ready for it. Meet me by the pond at sundown." It wasn't a request, it was an order. If it had been about anything else it would have irritated Zuko no end that somebody was bossing him around, but he wanted to learn. And besides, this was Katara. He nodded in confirmation and set off to be the Fire Prince.

Katara stood by the pond watching the sunset as the deep red colours dissolved into a soft blue in the water. She was bracing herself for what was to come. As soon as she did this, she would not only be giving Zuko as much power as she had, but she was also giving away a part of herself. She had decided to postpone teaching any sort of blood bending for now - a part of her still did not trust Zuko's fits of anger, even though she was sure he would never intentionally use it for harm. The incident with Toph's burnt feet sprang to mind. She felt slightly guilty remembering those times - nobody could deny how much he had matured and how much more control he had of himself. But she could decide about blood later. For now, she had made a deal to teach him water bending. And since he had kept his part of the deal, so would she.

Zuko left the last advisor as the sun was already drowning below the horizon. He hurried to the gardens dressed in his usual training gear to meet Katara. Sure enough, she was standing with a very distant expression while gazing into the water. In the half light of late sunset, the shadows cast on her face accentuated her cheek bones on her too-thin face, and how her expression was drawn into an inexpressive mask. He found himself wondering, as he had since she returned, what had truly happened on her journey. He knew that she only mentioned the good parts, omitting any hardships she may have faced. She had mentioned anger and frustration, but those were easy emotions to talk about. And they were simple excuses for sadness.

Without warning, she turned her head and locked eyes with him, as if to find something in his gaze. She maintained her stoic face and betrayed no emotion. Zuko didn't like it. He had used the same mask since sadness and regret and shame had overrun his life and he knew how simple it was to hide behind indifference. He also knew how unhealthy it was. Masks do not solve true emotions, they simply bury them deeper, so that when they do eventually resurface, they are even uglier than before.

This emotionless-ness did not suit her at all. Katara was always one to wear her heart on her sleeve - to shout and cry and laugh at what was happening around her. It was one of the things that had warmed Zuko to her in the first place; he had relearned how to live in some semblance of normality. Strangely it was Katara who had helped him, not anybody else. She was gentle and kind (when she wasn't trying to kill him, he remembered ruefully) and she respected silence as well as words. He needed somebody like her to reach a helping hand out and pull him out of the hole he had been digging for himself since his mother's disappearance. Only then could he truly appreciate his uncle and his friends. He owed her so much.

So now that she was struggling with some silent demon of her own, he longed to help her, to prove that he had learned from her. He did not like to see her suffer, even if it was in silence. But how?

Katara broke eye contact and lifted her eyes to the darkening sky.

"Give me your hand, Zuko," she said, reaching out for him. He moved closer, wary of her mood, and laid his hand on hers. Once again he decided that he enjoyed the feel of her skin on his, but was distracted when he felt something in him shift inexplicably. He noticed that she had closed her eyes and was controlling her breathing - she must be altering his chi flow!

Suddenly, she ripped her hand away from his, as if the thought of their physical contact repulsed her. It couldn't be, he reasoned, she had touched his scar that morning. Or was she simply feeling guilty then? Maybe…

His thoughts were interrupted when she told him to sit down like they had in the morning at sunrise. The world was being plunged into that awkward darkness between sun and moon.

"We are going to meditate like we did with the sun. Only this time you need to look for something a bit different. Having now done some fire bending and having meditated with the sun I know the differences. With fire, you use exact, sharp moves because you are controlling heat and energy. Water is different although no less powerful. Water flows; even at its most destructive it is all connected. A wave doesn't occupy a sharp space, it leads from and into the rest of the water, and it doesn't just disappear. That is what you are trying to feel, this connectedness. The movement of water is always a push and a pull; you must feel the power of the moon and then channel that power through yourself, just like the moon pulls the tides. It is not something easy to detect - it is like the fact that everything falls to the ground, it is something you take for granted, but if you focus you can feel the force of the moon calling you. It is calling your blood. We had to start tonight because it is a full moon, when this feeling will be its most powerful. Come, let us feel the moon rising together."

They trained for a couple of hours after sundown, but it took a long time for Zuko to finally connect with the moon's power. When he finally did and managed to lift a sliver of water from the pond - reminding Katara of when she had first started - a bright light momentarily blinded them.

When vision came back, a familiar unearthly presence was floating on the water; a girl, beautiful and wild and translucent yet emitting all the power of the moon's light.

"Yue," breathed Katara, throwing herself on the ground in a deep kowtow to the moon spirit. Zuko did the same almost instinctually. He felt giddy with all the energy that was coursing through his body, but it was not like fire; fire grew and pooled in his stomach, but this seemed to pull him together and tear him apart from his heart.

"Come Katara, we were almost sisters, you do not need to bow to me! Rise Zuko of the Fire Nation," her voice seemed to be carried on the breeze.

"Yue, I'm sorry if I have disrespected you, I can take away the water bending if you wish it!" Katara had real fear and reverence in her voice, but Zuko felt something squeeze his heart; he did not want to lose this. It had been only a few hours but he felt so much more aware, so much more alive…

"No, I have come to warn you though. Not everybody is like the two of you, not everybody has your power, your strength and potential. Do you know what happened before the turtle-lion cities?" Katara and Zuko shook their heads, listening in awe, hoping that they could learn where the strange book had come from. However, Yue just smiled sweetly. "Then that story will have to wait for another time. Katara, a long time ago my children were scattered - those who knew most about the world you live in. They have been forgotten, but they continue to be drawn to one another, as I draw the tides. You will find them as some of your closest friends," she said, looking down at them affectionately.

"Learn well and learn fast Prince Zuko! The world has been thrown out of balance, but my students will always have the power to pull it back into place. I will be watching…" her voice drifted to them, fading with her image and returning them to a deeper darkness.

Zuko and Katara stared at the place Yue had just taken up and then at one another, completely bewildered.

"Well. I honestly don't think that could have been any more cryptic!" said Zuko softly, trying to relieve the tension. Katara grinned. She could relax; Yue had told her it was alright to teach Zuko! She had also told her many things she did not understand. She quickly pulled out her black notebook and started scribbling the words Yue had uttered, exactly as she had just said them. There was more to this, they had stumbled upon something significant here. Zuko watched her, occasionally correcting a word.

Katara looked up at him from where she was sitting on the ground, closing her little black notebook.

"I think that meant that you are welcome to the family," she said with a smile.