Disclaimer: I don't own Avatar: The Last Airbender.

Title taken from Sam Smith's song of the same name, which is where the plot bunnies came from in the first place. Listening to the song while reading is highly recommended.

Enjoy!

Zuko sees the kiss.

Everyone else is still inside, drinking tea, celebrating his coronation and the end of the war. He only vaguely hears Sokka indignantly justifying his sub-par artwork and Toph butting in with a typical snarky comment, his focus intent on the green-clad waterbender who had ducked outside when she thought no one would notice.

But Zuko had noticed.

He's not quite sure when he started feeling her absence so keenly, started missing her presence when she leaves the room. But it becomes very obvious to him, the moment she slips out from behind the table to follow the Avatar outside, that he has somehow let an attachment to the young woman worm its way into his subconscious. It's all very unsettling, and sends a nervous rush of adrenaline shooting through his system.

He used to think that the possibility of a friendship with her lay somewhere in the realm of Azula starting a shelter for the homeless or his uncle swearing off tea- impossible. But then, against all odds, she had accepted him even after his horrible betrayal, fought by his side against his sister, cried for him after he'd taken lightning for her.

And now he is finding himself with the strangest pit in his stomach as he watches her disappear out the door.

Zuko doesn't know why he can't look away when her lips meet the Avatar's. Common courtesy dictates turning a blind eye to a couple so obviously seeking a private moment. He knows he looks strange and antisocial standing off to the side, clearly disinterested in the conversation between his friends around him. He is fairly certain that Mai is still waiting for him to return to her side on the other side of the room.

Yet his ocher eyes are glued to that narrow sliver of a scene he can glimpse through the doorway. Time seems to slow a little as he watches the pair embrace and lean into the kiss as if moving through molasses. His heart stutters in its steady rhythm and the air seems to have been forced out of his lungs, as if he has been knocked abruptly off balance. The kiss seems to take an eternity, and with every passing second he knows he should stop watching, feels the growing guilt at witnessing such an intimate moment. But he can't bring himself to pull his eyes away, until someone calling his name- the voice vaguely registers as his uncle's- shatters his stupor and brings him back to earth.

"More tea?" the venerable firebender offers, but Zuko waves a hand.

"No thanks, Uncle." And he turns away from Iroh's too-insightful gaze to amble off in search of his girlfriend, shoving the image of Katara and Aang forcibly to the back of his mind. If anyone had questioned him, he would have pled ignorance of the entire event.

But in truth, Zuko's eyes had been opened, and to more than just the knowledge of the budding relationship between his two friends. Somewhere in the back of his mind, he had been maintaining the expectation of things between himself and the waterbender remaining as they'd been on their journey- traveling together as friends, sharing meals and laughing and fighting alongside each other. In some way that he doesn't quite yet understand, or at least want to admit, the kiss has woken him up from that expectation as though jarred awake from a pleasant dream.

It's a few months later when he sees them next. The Avatar is returning to the citadel to check in on how the Fire Lord's project is progressing: the rebuilding of a nation crippled by the effects of a century-long war effort. Zuko is at his desk, poring over paperwork (as usual) and avoiding his girlfriend (also becoming usual), when one of his staff comes in to inform him that the Avatar's bison has been spotted.

He watches, feeling very stiff and still slightly awkward in his formal robes and crown, as Appa lands in front of him, bearing the couple he has been endeavoring to avoid thinking about since his coronation. Focused blue eyes catch him in their gaze as Aang airbends off his bison with his characteristic impatience. Zuko feels a twinge of annoyance as he watches Katara awkwardly clamber off the saddle and slide down by herself, even as he is nearly knocked over by the younger teen's forceful hug.

The least you could do is help her down, he thinks, inwardly rolling his eyes at the immature excitement of the young airbender. Outwardly, he smiles. "Welcome back."

Aang steps back from his tight hug (Wow Zuko, you look so much older! Can you believe it's only been three months? I have to catch you up on everything-) and they exchange bows. Then Katara is walking up, and he has to remind his heart to keep a normal rhythm. He moves to bow, and she pauses, bowing in return, just as he and Aang had done.

Then, before he quite realizes it, she has stepped forward and embraced him, and for the briefest of moments, Zuko feels again as if he's been knocked off balance. He feels her warmth for a heartbeat before she has released him again and he can't do anything except stare. She smiles. "It's good to see you."

Then her hand intertwines with Aang's, and Zuko has to force himself to smile back. But he finds that his reply is still honest.

"Yeah, it is."

If only he could be as honest with himself.

Later that evening, after dinner, he almost stumbles into another moment. He is about to walk into Katara's room with tea, hoping to keep some semblance of the relationship they'd had while traveling, when he sees through the crack of the door that she is not alone. Pausing in the corridor, he does what he knows he shouldn't, and eavesdrops.

They're laughing, reliving some story from their travels as they sit close on her couch. Her head rests on his shoulder; his arm snakes around her waist. His name slips out of her mouth, sandwiched in between giggles. And then he leans across to kiss her, stopping her laughter, and Zuko doesn't stay to watch this time.

He breaks up with Mai the next morning. Something in her steady gaze, in her lack of anger and her almost pitying eyes, makes him wonder if perhaps she knows more of his own emotions than he does.

After that visit, he comes to dread spending time with his two friends, cursing his firebending training and his years as an exile for making him so vigilant, so aware of every detail. He sees every intimate glance that passes between them, every silent laugh at an inside joke, every slight brush of their hands against the other's shoulder, waist, arm. He hears whispered words that were never intended for his ears, catches accidental glimpses of moments not meant for anyone's eyes, especially not his.

So every few months for the first year after the war, when the Avatar's bison appears in the sky, Zuko feels his heart drop into his stomach and almost unconsciously prepares himself for impending suffering.

It occurs to him occasionally that he should be happy for his former traveling companions. They seem happy together, after all. Aang seems to be treating Katara well, from what Zuko can see of her smiles when he spends time around the couple. Although admittedly, it is strange to watch the fourteen year old act the boyfriend to a young woman two years his senior, especially a young woman who had spent the majority of their time together before dating as more of his mother figure. But when he spends much time at all dwelling on it, which isn't often, Zuko thinks that this shouldn't be cause for objecting to their relationship so instinctively.

No, there is something deeper coming into play. But this is as far as he ever dares go with this train of thought.

After the first year passes and both Aang and Zuko are reasonably confident in the way things are progressing in the Fire Nation, the visits trickle to six months apart, then a year. The Fire Lord doesn't know how to feel about this new trend. He does miss them, of course; no strange, unexplained feelings will ever change how much he cares for the both of them as some of the only people in the world who have ever seen all of him, the good with the bad and all the parts that weren't quite either one. The bond forged from traveling together to defeat Ozai is a strong one.

But the physical pain Zuko feels at seeing them together, as a couple, knowing that they spend most of their lives traveling together, forging new adventures and overseeing the restoration of the world after a century of war while he is tied to the throne of his own nation, is real and difficult to endure. And so it is something like a bitter relief when the Avatar begins to come less and less frequently.

With this shift in arrangements comes an unexpected development.

It's an unusual rainy day when Zuko receives the first letter. An aide comes to his office during mid-morning to deliver the mail, as usual. He flips through the stack, automatically sorting through official business, urgent messages from routine ones, setting personal correspondence (a letter from Uncle in Ba Sing Se, the occasional update from Toph- oh look, the invitation to Sokka and Suki's wedding I've been expecting) to the side to read later, at his leisure. An envelope containing no return address momentarily gives him pause, stilling his busy hands- who would send the Fire Lord mail without identifying himself? Interest thoroughly piqued, he slits the missive open with a letter opener and pulls out a single sheet filled front and back with unassuming but elegant handwriting.

"Zuko-" the letter begins, and rather than immediately reading the body of the letter, he flips the paper over, his golden eyes skipping to the signature to see who would address him so informally.

"Katara." He reads the name aloud, eyes opening wide. Quickly, he flips the sheet back over and starts to read from the beginning.

Zuko-

I've missed you!

I know that the Fire Nation is doing well, that you are more than capable of handling everything without Aang's diplomatic presence. I know you don't need us to come and visit so much anymore, and that we have our own roles for now. But I do miss coming to see you, seeing the citadel and spending time on the beach and getting to explore the palace attics. (Remember when we found the funniest baby portrait of Iroh?) You could have a whole adventure just going through the old storerooms in your palace, you know. You'll have to take a day off from paperwork the next time we come to visit so that we can find your embarrassing baby pictures this time.

I know you must be swamped with your duties as Fire Lord, and I don't want to take away from them, or ask anything unreasonable. But I would really like it if we wrote to each other. I miss spending time with you like we did when we were traveling together, and would hate it if the time apart put distance in our friendship.

There's no return address on the envelope because Aang moves around so frequently, and we are never in the same place for very long. I guess he's used to that lifestyle, being an Air Nomad, after all, and I've been getting accustomed to it as well, although I think I'll always prefer having one place to call home. But I did send this letter with a specific messenger hawk who's been trained to seek us out when he needs to find us. (It looks like previous Avatars had this problem with mail, as well. There's just too much demand on their time in too many directions, and so they're never in one place very permanently.) But anyway, if you send a return letter back with that hawk, he'll know where to find us!

Of course, if you're too busy to write back, or aren't interested for whatever reason, you can just send him back without one, as well. I'll understand.

The rest of the letter describes her current life traveling with the Avatar, mostly focusing on the help she's been able to give the healers in the villages they pass through and how rewarding it is for her. She includes a little of the diplomatic duties Aang faces as he visits different locations in the Earth Kingdom and Water Tribes, and ends by asking him to write back soon.

A letter back from you would make me really happy! It gets a little lonely sometimes, with no friends around besides Aang, and it would be nice to hear from my favorite moody firebender.

Regardless, know I really value your friendship and believe in your ability to shape your nation for the better. The crown looks good on you.

-Katara

A strange feeling rises in his chest at her final words, and pushing his other papers aside, he grabs a clean sheet and some ink and begins to write her back. A small smile turns up the corners of his mouth. Shaping his nation for the better can wait for a little while longer today.

She's stupid, he thinks absently as he writes, to believe him capable of disappointing her in anything.

Time passes, as it does, and Zuko is twenty-two almost before he knows it. The years have been peppered with paperwork and pushy advisors. He's quashed at least two potential civil wars before they had the chance to come to fruition, drank at least an ocean's worth of tea, and negotiated more alliances and trade guidelines and peace agreements than he knew there was paper enough to write them on. All while fending off the subtle but ever-mounting pressure from his advisors to find a bride and solidify his rule, he might add. (His dynasty, actually, as they so loved to call it. Privately, Zuko finds it strange that he could be said to have anything like a "dynasty." He still finds it strange not to be an exile, to be perfectly honest.) All the while, he has continued to send letters back and forth with Katara, their correspondence a ray of sunshine in the oftentimes dull and frustrating task of being the Fire Lord during peacetime.

But suddenly, summer is approaching, along with the five year anniversary of the end of the war, and he finds himself in the position of hosting a celebration of peace. He has just taken care of the misguided leaders of another would-be rebellion born of the nationalist roots that ran deep in the hearts of many firebenders, and had written a letter to the leaders of the Earth Kingdom and both Water Tribes, as well as Aang, requesting a celebration to take place in the citadel. He hopes it will help remind his people that a great evil has been eradicated, that this is the beginning of a new era.

The fact that a certain waterbender, who he hasn't seen for at least a year now, will also be required to attend in her newly official role of Southern Water Tribe ambassador is just an added bonus. Or unfortunate drawback? He can't decide.

A month before the diplomatic delegations are due to arrive, Zuko starts to doubt his wisdom in planning the festivities.

A week before, when he wakes up in a cold sweat after multiple nightmares involving public humiliation (and lots of Katara and Aang in intimate positions), Zuko knows it was a terrible idea. The youngest current world leader- of the nation which had terrorized all others for a century, no less- should not be hosting a celebration of peace.

The good of my nation before myself, he tries to remind himself. He has an entire country to think about.

So why, in his quiet moments, is his head only filled with memories of that first kiss, and the many others he has accidentally witnessed between the couple over the years? Of every time she's smiled at him, sent him encouraging letters during the darker times of these first five years as Fire Lord, shown him unbelievable kindness- only to then witness her embracing the Avatar, kissing him, loving him?

Zuko has spent five years in absolute denial. So when he picks up a letter on his desk, just five days before the celebration is set to begin, and sees her familiar handwriting on its envelope, he is surprised when he feels no desire to squelch the usual increase in the tempo of his heart.

Dear Zuko… know the preparations must be stressful to pull together… excited to see you… can't wait to talk… confident that you're doing the right thing, as always, for the Fire Nation.

How is it that she always knows just what he will most need to hear? It's practically psychic, the way she can anticipate his emotions and insecurities and head them off with a well-written word of truth and encouragement. And it's then, staring down at the letter in his hands, that Zuko realizes in a flash of understanding what he's spent years avoiding and denying and trying to overcome.

He loves her.

He is hopelessly, unfortunately, painfully in love with a waterbender who spends most of her time half a world away, loving someone else.

It is simultaneously the most wonderful and horrible thing he's ever experienced, this realization, and he spends a good while just staring down at the paper that's somehow managed to shift the very earth under his feet with just a few lines.

I love her.

He doesn't know whether to jump for joy or collapse in horror. So he does the next best thing- he heads to the practice arena for a cathartic session of firebending until he is too sore to stand.

However, all the training in the world won't let him avoid dealing with this newfound truth. He finds himself staring at her letter often over the next several days, distracting him from the preparations and leaving him continually unsettled. Although it is a relief to finally realize the truth behind his conflicting emotions, he has no idea what to do with it. After all, she's with the Avatar. And so he tries to push the feelings away, tries to focus on the important things.

When the day finally arrives for the week of celebrations to begin, the introductions to boring diplomats seem especially unbearable to the young Fire Lord. He feels as though he is craning his neck after every new round of pleasantries, searching for the telltale sign of Appa descending from the sky. Even the arrival of his uncle from the Earth Kingdom, long-anticipated, only brings him momentary relief.

Zuko gets his wish late in the afternoon after most of the other guests have arrived. The Southern Water Tribe delegation is already there, containing among their number Hakoda, Sokka and Suki (newly married), and an elderly woman he vaguely remembers from that first unfortunate landing at the South Pole. It had been his pleasure to welcome them- her family- into the Fire Nation's capital. Toph had also arrived, giving him a friendly slug to the shoulder even when he had tried to greet her with more manners. "Hey, good to see you, Sparky."

So when the bison appears as a small dot on the horizon, it feels as if a final missing puzzle piece has been found. Zuko isn't sure what to expect of himself upon seeing the waterbender again, not after his personal revelation a few days prior.

But he definitely doesn't expect his blood to freeze in his veins as she slides off the bison after Aang, a smile gracing her features and a new necklace accenting her collarbone.

He only notices it because the ribbon, instead of the worn blue of her mother's heirloom, is a bright silvery color instead. His too-observant amber eyes focus on it immediately, as well as on the couple's intertwined hands.

Zuko is not the only one to notice this change in Katara's wardrobe. Hakoda steps forward to embrace his daughter, and congratulates the couple. "I am happy for you, Katara," he says gently with a smile, seeming to have expected this development. He turns to Aang next. "I know you will be a wonderful addition to our family."

The Avatar bows to the chief of the Southern Water Tribe respectfully, with a smile nonetheless. "I deeply appreciate your blessing on our future marriage."

Zuko can't breathe. He tries desperately to school his features into a neutral expression, avoiding Uncle Iroh's knowing eyes, hoping his inner turmoil isn't apparent on his face. None of her letters had hinted at something like this. Logically, he thinks he should have expected it soon- they had been together for five years, and they were young, yes, but also world leaders and war heroes. But maybe for the same reason it had taken him so long to realize his feelings for Katara, he also hadn't wanted to dwell on the possibility of her probable marriage to another man.

Once he has spent several rapid heartbeats absorbing the news, he is able to arrange his features into his best approximation of happiness. Blessedly, it is only after he feels he is back in control of his emotions that Aang and Katara turn to him, and he has an opportunity to give his congratulations.

"I am truly happy for you," Zuko offers, his eyes locking with Katara's as he finishes his sentiment and finding that his words are indeed honest, at least towards the waterbender. I just want you to be happy.

She smiles and thanks him, but there is something tight around her eyes that Zuko wonders if he is imagining. The group turns to head back into the palace, Aang running ahead to catch up with Toph, and Zuko finds himself at the back of the group, beside the newly engaged Katara.

He gives her a sideways glance. She grins, meeting his eyes, and suddenly that strange tightness around her expression melts into mischief. "This doesn't disrupt our plans to go searching for humiliating portraits of baby Zuko, does it? You've weaseled out of it for years now- you're not getting away with it this time."

The laugh that bubbles past his lips is genuine, not forced, although there is still a very real ache in his chest. "Anything you want," he promises. There is a note of underlying seriousness in his tone, and he wonders if she catches the meaning he has to leave unspoken. The way her blue eyes cut away from him to suddenly study something fascinating about her nails makes him think that she might.

That night, there is a welcome banquet that serves to double as Aang and Katara's impromptu engagement celebration. He is seated near the couple, and as usual, his highly trained skills of observation leave him with more knowledge than he'd prefer to possess.

He doesn't want to see the infatuated beaming smile on the Avatar's face every time he looks at his intended. He doesn't want to witness the whispered comments that pass between them, or the way Aang's hand is all too comfortable resting possessively on her thigh under the table. Images from his nightmares come back to assault him in full force, and he has little recourse for beating them back now that his wall of denial has been destroyed.

But the part that hurts most of all, the worst thing about his attention to detail, is seeing Katara's reaction to it all. She smiles, yes, but it doesn't reach her eyes. She accepts the attention, allows the physical contact, but doesn't reciprocate it. He loses count of the times her hand rises to the necklace at her throat, fingering the charm almost obsessively. He's seen that habit before- she would do the same thing during their journey when she felt nervous or threatened or upset. He watches her fingers trace the smooth satin of the new ribbon and wonders what is driving the habit now.

Zuko can't bear it, because these observations simultaneously cause him to doubt her happiness and give him hope. He cannot afford either response, not if he is to make it through the celebrations and the years beyond. But the longer that dinner drags on, the more certain he becomes that something is not quite right with Katara. The tantalizing possibility teases at the edges of his imagination and is enough to keep him desperately wondering.

Is she not truly happy with him?

As everyone eventually rises from the table late in the evening, looking forward to their beds after a long day of travel, Zuko happens to lock eyes with her once more. He sees mysteries swirling in their depths before she smiles politely, slamming the proverbial door shut once more, and he is left to merely guess at the state of her heart.

"Portrait hunting tomorrow?" she asks, and the Fire Lord feels again how impossible it is for him to deny her anything. He sighs.

"Tomorrow," he promises, and the expectation of future embarrassment is more than made up for by the genuine excitement in her expression at his easy acquiescence. He watches her fiancé lead her down the hall with a hand on the small of her back, regrets and nostalgia threatening to overwhelm him.

He doesn't really expect to be able to sleep that night, and so sits at the desk in his room instead of moving immediately to his bed. A quick motion of his fingers lights the various candles around the room, and he sinks into the chair, resting his elbows on the glossy wood and placing his head in his hands. His crown and topknot are long discarded, his more familiar shaggy black locks falling around his face, obscuring his face.

He doesn't know quite how long he sits like this, just focusing on breathing in and out, the sound of his heartbeat loud in his ears. But when he comes to himself again, he sees out of the corner of his eye a familiar piece of paper.

Her letter.

Zuko picks up the sheet with slightly trembling fingers, reading and re-reading the words she'd written until his vision suddenly became too blurry to continue making them out. Confused, he reaches up a hand to his face to feel something foreign and wet making its way down his cheeks. Bringing his hand away again, he stares at the moisture on his hands uncomprehendingly.

He feels like an incompetent adolescent again, a young boy on an impossible mission that he is nonetheless honor-bound to complete. Only this task- letting her go- seems far less achievable than his long-time hunt for the Avatar ever had.

Carefully setting aside her letter, Zuko's eyes fall on the stack of paper he keeps on the corner of his desk. How many times has he sat in this exact spot to pen her a reply?

Struck with inspiration, he shakes off his silent tears, takes a sheet from the top of the pile and pulls out his writing utensils. Katara, he begins, taking care while forming each character of her name. Then he pauses, leaning back.

He's missed the crucial flaw in this plan to take action against his wayward emotions; he has no idea what to write.

Several drafts ensue, failed attempts at continuing the easy rapport they had always shared through their correspondence over the years. He groans in frustration, burying his face in his hands. "Why can't I get this right?" he almost growls under his breath. Around him in messy piles are the slightly crumpled results of his struggle.

Then, it hits him. Things aren't coming out right because he is desperately trying to conceal his heart from her, introducing into their friendship something which has never before existed: falsehood. Leaving him with only one possible, albeit painful, solution.

Shaking his head with the audacity of what he is about to do, Zuko is nonetheless compelled to be truthful. He owes her that much. And so, with trepidation speeding up the beat of his heart, he puts pen to paper and begins to write.

I feel like I'm lost, like I have no direction…

…been waiting so long…

…do you know how it feels to see you with him, to hear you calling out for him…

…feels so alone, without you…

So this is what I'm asking.

He pauses, hand shaking, and draws a deep breath before continuing.

I promised that I would never betray you again, after what happened under Ba Sing Se. And lying to you feels like a betrayal. I feel honor-bound to tell you, Katara, that I am in love with you. I'm not sure when exactly it started- it must have been so long ago. I have been such an idiot, denying it even to myself. But now that I know, I can no longer deny it to you.

So this is what I'm asking, what I'm offering. Pack up, leave everything. Leave what you've known for years now. Leave your life with the Avatar behind. Don't get married. Come here, to the Fire Nation, and live with me. Love me instead. You know, you have to know by now that I am incapable of withholding anything from you. You would have everything from me, all of my heart. I know you could be happy here, with me.

If you are happy with him, truly happy marrying him, then ignore these words. I hate feeling selfish, and I feel selfish by giving you this option. If I were sure beyond a shadow of a doubt that you are content with the choice you've made, I wouldn't offer. But since after tonight, I have even the smallest bit of hope that maybe, maybe you aren't quite as sure as you'd like to be, I have to ask. Make me the happiest man in the world, and I promise that in return I will spend every day making you the happiest that I possibly can. Give me the chance to show you how much I love you.

So this is what I'm asking. It seems unfair, selfish, impossible even. But if there's any part of you that could reciprocate what I feel for you, any possibility that you believe you could be happy with me, then leave your lover, Katara. Leave him for me.

-Zuko

It's late by the time he finishes the letter with the familiar flourish of his signature, midnight at least. Placing it inside an unsealed envelope, her name carefully inscribed on the front, he stares at it in mild disbelief.

Has he really written those words? Is this all a dream? Does he truly intend for Katara to read his request? Does he really mean to put her in such an impossible position?

His heart answers for him with a violent surge of emotion as he considers letting the letter slowly burn in his hands. The expression in her blue eyes haunts him, the memory of her veneer of happiness appearing as a thin layer of ice over an ocean. If it weren't for his damnably acute skills of observation, Zuko might be able to reduce the envelope in his hands to ashes. But he can't erase what he's seen, can't burn away the doubts in his heart, and so his compulsion to maintaining the honesty in their relationship stills his hand and leaves him as frozen in place as if she had bent the ice to do the deed herself.

Leave your lover, Katara. Leave him for me.

He means those words, truly and sincerely means every stroke of his pen on the paper. He hadn't officially proposed marriage, but he knows she will take his meaning; he's practically shouted it in every sentence.

Since his silent witness of that first kiss, five long years ago, it's always been her. He knows in his heart that he doesn't have a choice.

Allowing himself just a moment in which to envision a happy outcome of this letter, a universe in which his laughing blue-eyed children firebend through the halls of the palace and their mother sleeps soundly beside him in bed each night, Zuko sucks in a deep breath, runs his hand through his messy hair, and moves to rise from the desk.

He has a promise to deliver, and there's no sense in delaying.

Author's note: This is the first time I've really tried my hand at writing for ATLA. I got really into the series when I was younger, and there are several half-formed fic ideas on my computer that I never got around to finishing. I just hated the way the series ended in the romance department, and as a result, when Korra came out I never really could get into it. I love Katara and Zuko together. :)

So since I finished my Inuyasha fic a few months ago, when inspiration struck in song form earlier this week, I decided it was high time I had a little fun with my favorite couple from my favorite childhood show. I'm considering writing a companion one-shot from Katara's perspective, but since my time has been extremely limited lately, that might be just wishful thinking.

Thanks for reading, and I'd appreciate it if you left a review! Constructive criticism is always welcome.

-Lady E