Aang seems happy enough, but Katara cannot imagine why. She stares out at the ocean, standing on the dusky beach, angry and itchily so, as if her fury is an uncomfortably tight coat she can't pull off, heating her chest and neck and confining her lungs. Her breathing is harsh and labored in this heat- the tropical humidity of this island, so lovely those first weeks, is getting to her, and she would trade anything to be in the South Pole right now.
"Katara?" she hears, and she whirls to snap at him, her feet carving angry little valleys in the sand. He has snuck up on her, this boy with whom she thought she was in love.
"What, Aang? Are you finished being all high-and-mighty and pretending you know best?" His eyes widen and his mouth hangs open with hurt, and some part of her hurts too, but a stronger part is filled with pent-up vitriol and another, much smaller part feels a perverse pleasure in hurting him for a moment. "Get over yourself, Aang, you're thirteen. You don't always know best. You're just a kid." This is a stab and she knows it, and enjoys it, and wants to twist the knife a little, because he deserves it, after the way these past months went.
But instead his grey eyes- pretty eyes, eyes she once idly thought would look nice next to the dark hair she will pass on to her children- go sober and droop a little, and his mouth closes, and behind the infuriating maturity that usually pleases her when it appears is a hint of a wound. A hint isn't enough for her, but before she gets out another word, he speaks.
"Katara, you're not being fair," and it is a statement of fact, not an entreaty, not a persuasion, and immediately she opens her mouth to speak but he continues. "I'm the Avatar. I'm not just Aang, and I can't be. I have a responsibility to the world. You know that." She does know it, but he can't be the mature one of the two of them, not in this fight and not ever, not when he is two years younger than her (and let's be honest: she is just a kid as well) and kissing him in public makes her self-conscious (like she is a pedophile or something!) "And I know I can't always be right and I don't know best. But it's important that I do my best to keep the peace." And dammit, he is still talking. How dare he be right? How dare he be so superior? "I mean, it's on my shoulders, Katara-"
"Shut up," Katara snarls finally, and storms past him, because he is right and for a moment she hates him for it. She does not get very far before she remembers the letter from Sokka that arrived earlier that day (her brother needs her to visit Zuko in her capacity as diplomat) and turns to spit curt words back at Aang, confused, upset, dear, hated Aang. "I'm leaving tomorrow. For the Fire Nation. Sokka needs something from Zuko and he can't send anyone else." Even now, Aang keeps talking.
"Why don't you just write to Zuko?" he suggests, utterly earnest and trying to help her even after she snapped so cruelly, and this goodness of his infuriates her even more. "I mean, he'll give you what you need. He wants the world peaceful and happy just like we do-"
Her words, barbed and angry and only half-true, come through a clenched jaw. "It's a complicated manner. And that isn't the way diplomacy works. It's not something you could understand." With that she turns from him and walks away.
Katara finds herself packing her things violently, shoving them into her bag, with no memory of her walk back to their inn (the powers-that-be of the island had arranged for the two teenagers to stay in separate rooms; the discovery of this relieved Katara immensely upon their arrival.) As she packs she comes across Sokka's letter and skims over once again- she has already read it a good three times and is still not entirely certain why he did not just write to Zuko, as Aang had suggested merely half an hour ago.
Sokka wants her to ask Zuko for warships and firebenders; that much is clear. Pirates have been taking advantage of the chaos caused by the war for as long as it has gone on, raiding and plundering in both the south and the north, and Sokka has decided it is finally time to address the issue. But the request is modest, and in a time of relative peace- if not particularly organized peace- their friend the Fire Lord can certainly afford to loan them a few ships and soldiers. Besides (and she hates that this thought even crosses her mind) Aang was right before: Zuko will certainly give what is needed, because he wants the piracy under control as much as Sokka does.
All told it is not a matter that requires formal diplomacy (yet Sokka has made it clear that that is what he expects- the letter ends with an admonishment to "bring something nice" because she will need it) and Katara doesn't understand. She puzzles over this for a while, lounged on her bed and examining the pale green ceiling, but finally she just accepts it, because she wants to get off this island and doesn't particularly care about the pretext. It will be nice to see Zuko; his serious-eyed commitment to his serious position tickles her, and they haven't spoken in months, as she and Aang left just a few weeks after Zuko's coronation. Then it strikes her that if there is a free moment (and she doubts there will be) she can talk to him about Aang; whether he has advice for her or not (and she doubts he will) it will be comforting to talk to someone (and of this she has no doubt.) Katara smiles and closes her eyes, stretching her arms above her head.
A knock on the door breaks her out of her reverie, and she knows without a thought that it is Aang. There is a moment of silence in which her cheeks flush and her eyes flash open and her body tenses and her heart jumps, a moment of guilt and shame and tenderness and the pressure of a decision, and then she hears the knock again. Another moment. Then-
"Katara?" She knows now it is too late; she knows that had she intended to answer she would have after the first knock, and so she lets out a breath and curls up on her side, closing her eyes again and forcing her body to relax. Her heart sounds like a drumbeat, but she cannot help that, and the more she worries the faster, louder, harder it goes. The door isn't locked, and he is clearly here to check on her, so- yes, there it is behind her, the door clicking and Aang's gentle footsteps. Katara keeps her eyes closed gently, her breathing regular, and it is fortunate she is focusing so seriously, because Aang leans over to stroke her arm and kiss her neck and whisper into her hair ("I love you, Katara," and her heart nearly breaks) while her heartbeat pounds in her ears and she barely manages to keep control. He caresses her cheek, once, and then leaves, closing the door carefully behind him. Katara rolls over onto her back, staring at the ceiling, and lies there for a long, long time before she manages to sleep.