Katara leaves the Southern Air Temple with a spring in her step and all the youthful optimism to be expected from someone who's spent three months with Aang. His spirit is infectious. They arrive in the Fire Nation near sunset on the third day of traveling, and the sun is burning red against the scarlet roofs of the capital city. Zuko seems happy to see them; he's almost chipper.
Aang floats down from Appa's head and coughs dramatically. "Your Flameoness Fire Lord Zuko, I present Ambassador Katara, Southern Water Tribe, and his Momoness, Momo of the Southern Air Temple."
Zuko rolls his eyes but can't fight the smirk tugging at his mouth. He bows to Momo, who is perched on Aang's shoulder. "Your Momoness". Katara puts her hands on her hips, and Zuko turns to her, smirking just a little. "Peasant."
Katara protests for the rest of the day about how desperately Zuko needs manners.
It's been a few years since Katara has spent any significant time with Zuko, and she realizes quickly that he's changed (the only thing new about that is that he's not walking around announcing it). Some days, Zuko is the Zuko she's always known, broody and maybe a little angry most of the time (hiding the soft spots, naturally). He worries for his country and for Azula, sometimes for his own future. Some days, he's almost happy. He's at peace with himself, drinking tea with her and Aang in the gardens (maybe feeding the turtle ducks, when he's feeling nostalgic).
But this changed Zuko has other days, too. Some days, Katara waits in his office, and he's profoundly silent. It's as if his mind is empty, and he goes through the motions but his heart isn't in anything. And then, suddenly, after a day or three of this he's back to brooding (drinking tea if they're lucky).
Just the same, the three of them are enjoying being together again, more so when Toph explodes in one day and turns the palace upside down. She gives Aang someone to be young with, and Katara and Zuko retreat to his office. There's more work in peace than in war, but they can do without the Avatar for a while.
And so, on one of those days when Toph rolls out of bed looking for trouble and takes Aang down with her, Katara gathers her letters from the South Pole and makes a beeline for Zuko's office. He might be in a chatty mood today, but quite possibly a stormy one, but the odds of getting things done are higher than anywhere else. The Melon Lord and the Avatar are fond of drafting soldiers in their games. By the time Zuko is due to join her, Katara has made herself very comfortable, far away from the maids wringing their hands over Toph's indoor mudbaths (Aang likes to make them bubble, which only adds to their consternation).
Katara looks up when the door opens, and she inhales sharply. Zuko stands in the doorway, but his usually proud posture is just a little softly curved. The glow of his gold eyes has gone dull, framed by dark bags and his shaggy hair. She thinks it's likely he hasn't combed it. He's walking toward her now, but it's slower than yesterday, as if he has weights around his ankles. She greets him, and he looks at her with those dulled eyes, regarding her for a moment. A pause. "Hey." The rasp is quiet, emotionless, as if he knows he's expected to say it but neither knows nor cares why. He brushes by her and her eyes follow his back as he retreats to his desk. He sinks into the chair and Katara wonders just how old he is. It must be more than twenty. He moves like he's fifty and his joints ache when it rains.
She curls up in the window with her own work and watches him. Zuko is one of the best friends she's ever had, and she knows him like she knows herself. Today, Ozai doesn't haunt him, or if he does, Zuko cannot be bothered to feel it. It would be better that way, for him to be upset after looking in a mirror and seeing Ozai staring back at him, because he could be comforted then. Katara could reassure him, make him feel better. But today he's not feeling at all, and there's nothing she can do to help him. He doesn't want to be helped, nor does he feel it's necessary. He's not thinking of his family today, of his future, of his country, or if he is, none of it can reach him.
No, today, Zuko is silent and distant, though he'll apologize for it in the morning. Today, he'll draw in on himself like a turtleduck curling into its shell. He's ambivalent, apathetic. Everything is flat and gray for him, for no particular reason.
Today Zuko is not afraid of death. He might welcome it, were it handed to him.
There's no tangible reason, no way for Katara to reach him, no threat she can make or love and friendship she could profess that will bring him out of it. Tomorrow might be better, or the next day. But in the meantime, Zuko has no love of life, nor hatred for it. What scares her most, sends a chill deep into her bones and keeps her exhaustingly alert, is the flat apathy in his eyes.
Zuko is not afraid to die. And that could be dangerous.