Disclaimer: I own nothing you might recognise from the series.

Notes: Ravirn of the Infinite and KaliAnn both asked for the Gaang's reaction to Zuko's betrayal and absence. I'm afraid this got a great deal more abstract than they may have wanted, but that's what came out.

Each of them put it into words differently.

To Katara it was like something was colder without him there. Like something inside her froze over when every one of her prejudices against firebenders was proved to be right by the one boy who'd proved them wrong at every turn. At night she'd sit up to go look for her stuffed tiger seal replacement and then remember he'd turned on them and left with his sister, his evil sister, not his just kind of self-centred one.

So Katara had no one to confess her fears to that wouldn't either panic or baby her about them. She didn't have someone who would cuddle her instead of asking for comfort. She didn't have that person who would have backed her up when her father got so annoyingly overprotective and Sokka-like. Sokka had learned how to be a sexist jerk from somewhere, after all.

She loved her dad and had missed him, but he still saw her as his little baby girl, not the waterbending master she was now. He didn't see her as the practical force in their travel group with the Avatar, but as a child to be herded around.

Zuko would have helped her figure out how to make him see without letting all her anger at him leaving two kids and a bunch of old people to take care of his tribe in his absence spill out everywhere.

But Zuko was gone. Was a traitor to everything he'd ever said he believed.

The worst part was that she was Water Tribe. Family is everything in the Tribes. He'd left to be with his family, and she couldn't fault him for that, even as her fury at him for treachery got all mixed up with her anger at her dad for leaving and not just somehow knowing she'd changed, compounded by the stress of taking care of Aang and Toph without them realising she was doing it.

And stupid Sokka who kept interrupting her when she was just getting a good cry going because he couldn't leave her alone for a few minutes.

Sokka, who described it as the hole left when a member of your family was gone. Because Zuko was that brother he'd never had, the guy who got guy things and didn't think he was dumb for caring more getting to the goal than some airy-fairy notion of talking people into believing in truth and justice.

Hearing from his sister that Zuko had left them to go back to his family cut like a knife. All the more because Sokka just knew that Zuko was doing it because of some misguided attempt to take away the emptiness that was left by his evil mother and horrible sisters.

It made Sokka feel like he wasn't enough and made him cling closer to Katara because he had to be enough for her, he couldn't lose her too. He'd tried so hard to keep that empty look out of his friend's eyes, tried to keep the knife out of his hand, and he'd failed. He couldn't even be angry with Zuko, because those people the firebender called family had done it to him, had made him so lost he thought they were what families are.

Only with Master Piandao did Sokka unbend to speak of Zuko, even a little. Remembering careful lessons about how to grip a weapon tightly so it wouldn't go flying, but still loosely enough that you could be flexible in movement, gentle admonishment about stances and how each one led into another, gave you balance or let you lunge and pull back with ease, it stung less when he could put them into the context of other lessons on swordcraft.

But he hid from the rest as he struggled with Katara's unreasoning fury, Aang's confusion and Toph's grief.

Toph, who thought of it as a rhythm gone off kilter. A heartbeat missing from the surrounding percussion she was used to. The way everyone moved around everyone else now filled with hitches and sidesteps that confused her, prevented her from anticipating movements because there was a void where once a stable drumbeat had stabilised Aang's high-strung twitter, weaving a stolid backbeat with the steady ebb and flow that was Katara, counterpoint to Sokka's rapid and jerky movements.

There was no one now who got what it was like to feel like you weren't quite real, and Toph knew that she and Sokka might be the only two who really got that Zuko would have gone back because he was looking for something that was missing.

He wouldn't find it, any more than Toph would find it if she went back to Gaoling.

For all Sokka's sadness, Katara's anger and Toph's loneliness, Aang seemed to understand it the least.

Aang could put no words to it, only confusion. He'd only ever had family made and chosen, not family thrust upon him by fate. He'd so often envied others who had families, envied their bonds that seemed so unbreakable and strong in the face of bonds chosen and created in friendship. But he'd equally never understood it, never seen the way the blood could bind, never understood that.

So, while Katara snarled about how blood would out, Sokka shook his head sadly over the answers Zuko was seeking in the wrong places and Toph tried to hide her grief that Zuko would choose to go back, Aang struggled with confusion.

His teacher and mentor, gone. And for what reason? He was so confused by it all that reaching inside himself for those little voices that would grant him a hint of wisdom, a hint of experience that would explain something too complex, too far out of his understanding, would get him nothing. His chakras that he had come so close to clearing at Ba Sing Se were blocked and clouded once more.

Sometimes he'd get a wisp of sensation from them, faith, trust, a sense of connection to something more than the sum of its parts, deception and trickery. But none of them were more than a flicker, and none could offer him an explanation.

And in some ways, he was most honest of them all, because he didn't let notions of blood kin get in the way of the essential question they all asked and had no answer for.

Zuko, why?