The Fire of a Thousand Suns
Book One: Chapter 1
By Amphitrite II



Summary: On a sweltering summer night, Avatar Aang and Fire Lord Zuko discover their mutual attraction. But Aang marries his childhood sweetheart Katara, a slight Zuko spends years struggling to accept. Until one day, an older, wearier Aang shows up in the Fire Nation and tells Zuko that he's left Katara.
Disclaimer: This story is based on the Avatar: The Last Airbender and Avatar: Legend of Korra universe, their characters, and their situations, none of which I own.
Notes: Let's be real. This fandom needs more Zukaang, and this pairing needs more longfic. This is my humble contribution. Enjoy!




Present day, ASC 138

Three weeks after Tenzin turned eighteen, his parents announced their separation.

His father and mother had been together for thirty-eight years and married for thirty-two. They had raised three children, lavishing upon them the love and guidance that they had received in their early childhood, before extreme circumstances had forced them to grow up too quickly. The bond Aang and Katara shared, born in a time of war and allowed to flourish in the world they had saved together, was steadfast, loyal, and interminable — or so Tenzin had believed.

Aang declared the news with solemn straightforwardness characteristic of his later age. The once cheerful, reluctant hero had grown into a serious man, a change rooted in the difficulty of maintaining peace and healing the wounds sowed by the Hundred Year War, some deeper than he and his friends had ever imagined. Diplomacy had quickly worn away at his childish innocence. But with his children, Aang mostly maintained his cheer and love of goofing around. Kya and Bumi had inherited those qualities, but from an early age Tenzin had admired the authority his father held as a considerate but serious leader. All his life, he had striven to emulate that calm strength and to command that kind of respect.

"Dad, you can't be serious!"

Kya had shot up in her seat in horror, to nobody's surprise. Kya was always the first to react to anything, constantly wearing her heart on her sleeve. Tenzin thought briefly of her wild and impetuous adolescence years and winced. He hoped she wasn't upset enough to destroy any property through her waterbending prowess.

"Sit down, young lady," Katara ordered. "Let your father speak."

"Yeah, Kya," Bumi said in a stage whisper, poking her in the ribs. With a glare, she smacked his hand away.

Accustomed to the antics of his children, Aang continued as if he hadn't been interrupted. "I know you're upset, Kya. But I am serious. Your mother and I need some time to ourselves. We've been together for so long, and we love each other so much. But some space will be good for us. It will be good for all of us."

He covered Katara's hand on the table with his and squeezed it fondly with a smile. Always one to observe before judging a situation, Tenzin watched the exchange with morbid curiosity: His mother simply stared at the hand without smiling back. A sinking feeling overtook his stomach. Was there something his parents weren't telling them? Had Aang talked Katara into a separation that Katara did not want?

But Aang did not seem to notice anything awry.

"I will be leaving the United Republic for a time. I must deal with some unfinished business," he said cryptically. "You are all of age now. You don't need your doddering old man around anymore."

"Aw, Dad, don't say that," Bumi said with a grin. "We'll love you even when we have to feed you and clean up after you."

Aang laughed. Good old Bumi, Tenzin thought proudly. His eccentric and completely inappropriate older brother irritated the hell out of him most days, but if there was one thing Bumi was good at, it was brightening up an uncomfortable moment. Even Katara smiled at his words.

"I'm going to go visit the Southern Water Tribe," she said. "Which reminds me. Kya, I would like you to join me."

Kya wrinkled her nose. "Why me? Why not these dweebs?" She motioned to Bumi and Tenzin.

Katara's brows creased in a frown. "You know very well that Bumi gets shipped out at the end of the week and Tenzin will soon return to Republic City University," she said sharply.

"Yeah, yeah," Kya grumbled. "I'll think about it."

"That's all I ask," Katara said.

"Great," Aang said happily and almost nonchalantly clapped his hands together with satisfaction, as if he hadn't just dropped an enormous bomb on his family. He stood up and kissed his wife on the cheek. "I'm going for a walk. I'll be back for dinner."

Kya and Bumi cleared out almost immediately, engaging in an argument within the thirty seconds it took walk out of the room. Tenzin watched his father go and his mother stare after him with her hands clenched in her lap. Old age was suddenly apparent in her features — worry lines, weary eyes, slumped shoulders. She had shrunken steadily as he aged and shot upward like a hyperactive sprout.

"Mother," he tried. There was no use disguising the concern in his voice. Katara always saw past his attempts at suppressing his sometimes overpowering emotions.

"No, Tenzin," Katara said gently. "We've made our decision."

"Maybe," Tenzin said carefully. "But is it a mutual one?"

Katara stiffened visibly, pressing her lips in a straight line.

"Yes," she said. "I've kept him long enough."

With that, she rose from her knees and left a puzzled Tenzin at the table.

Tenzin sensed his father's approach before he saw him, Aang's step always light but purposeful on the ground. He marked his page with the orange leaf serving as his bookmark and closed the history book he was studying, setting the heavy tome beside him. Aang joined him under the tree, looking exhausted.

"How are your studies going, Tenzin?"

Tenzin looked at him thoughtfully. He severely doubted that his father had come to find him just to ask him about school.

"They're okay," he said. Aang made a humming noise of approval and picked up a leaf, twirling it between his fingers before letting it float away in the wind. A deafening silence rested between father and son. Patiently, Tenzin let his father gather his words as he stared at the sun glowing above the majestic curve of the mountains in the distance.

"You didn't say anything earlier," Aang said finally. So there it was. Aang wanted to know how he felt about the news.

Tenzin shrugged, not sure what to say. "The decision has been made. It's not up to us to dictate what you and Mother do."

"Yes," Aang said, "but your support would mean a lot to me."

Tenzin looked at the man he so admired and noted that, like Katara, Aang was showing signs of age and fatigue. It scared him more than he liked, the thought of his parents growing old. And now without each other? The idea seemed ridiculous and grieved him to imagine.

Carefully, he said, "What I don't understand is why."

Aang sighed and spoke slowly, almost pained, as if the words were not ones he was accustomed to or comfortable with speaking aloud. It was not often Tenzin witnessed such uncertainty in his father's demeanor.

"I love your mother very much," Aang began. "She has put up with so much throughout the years. She has done a wonderful job raising you all, and every day I wish I were as strong as her and always followed my convictions.

"Tenzin, many years ago, I almost left your mother. It was when we were dating. On a visit to the Fire Nation, something happened that convinced me I could no longer be with her. But you know your mother. She would have none of it. She forgave me for the wrong I did her and asked me to marry her." Aang smiled wryly. "We were all so young and so foolish. But I don't regret it for one second."

There were many gaps in this strange and surprising story, Tenzin knew, but he let his father continue. He had a feeling that Aang needed this more than he did.

"The thing is… Your uncle Zuko and I…" Aang swallowed, eyes darting to Tenzin nervously before skittering away. Tenzin had no idea what Uncle Zuko had to do with anything but knew his father was doing his best to explain. "Zuko and I are the best of friends. You know that."

Everyone on the planet knew about the legendary friendship between Avatar Aang and Fire Lord Zuko. Every child learned in primary school that it had been their willingness to work together that had ended the Hundred Year War, enabled war-torn nations to heal and rebuild themselves, and spread peace across the lands. Songs and nursery rhymes had been written about their epic alliance.

Tenzin was fond of Uncle Zuko, who had been a regular fixture in his childhood, since Aang insisted on taking his children to visit the Fire Nation twice a year. Tenzin would never tell anyone, but he knew that Uncle Zuko liked him best out of Aang's three children. Famous for his quick temper, Uncle Zuko was not very good with children — especially rambunctious ones like Kya and Bumi — but Tenzin had never been much of a child. He enjoyed talking to Uncle Zuko about politics and art and philosophy, although he had learned early on that history was a topic to be avoided.

Aang took Tenzin's silence as encouragement to continue. He took a deep breath.

"I'm in love with him," he said.

Tenzin couldn't help it — he gasped. But at the sight of misery on his father's face, he cursed his lack of control and tried to disguise his shock under a neutral expression.

"Father?" he said, mind racing as he tried to recall every interaction he had ever witnessed between Uncle Zuko and his father. He struggled to find something to say. "Does he know? Does…Mother?"

Aang continued, quieter and less certain now. "Zuko told me he loved me a long time ago and asked me to be with him. I hated myself for wanting to. And then, Katara… I married your mother. She convinced me that the feelings were nothing. I wanted to believe her, but the truth was that I never stopped thinking about Zuko. I still haven't." He looked Tenzin in the eye now and said desperately, "You have to understand, Tenzin, I have never intended to hurt anybody. Not your mother, not you children, not Zuko. But in my foolishness and cowardice, I have refused to accept the truth and in turn, hurt everyone I love."

The silence hung thick and heavy in the wake of Aang's pained confession. Tenzin hesitated.

"You're leaving us to go to him," he said. He instantly regretted his words, the accusatory tone marring what he had intended to be a simple question. He had no desire to add to his father's pain. But it hurt, the thought of his father, such a good man, leaving his mother because he wanted to be with somebody else. Still, if it was the truth, he had to know.

"Yes," Aang said. There was wonder in his voice, as if he hadn't quite realized that he had made such a radical decision. "For so long, I have tried to push the feelings away. I had a duty to fulfill, and I love your mother so very much. But you are all grown now, and time grows shorter for me." Tenzin noticed that his father's eyes were suspiciously watery, but he didn't say anything. "I am weary, Tenzin. Weary of fighting it. Long ago, Zuko told me that his flame for me would never die. If there's even the slightest chance of that being true… I have to know.

"Do you understand?"

Tenzin's mind flashed instantly to Lin, his girlfriend of one year and three months. He pictured her long, dark hair and her eagle-like eyes, steely and sharp except for the seconds after he kissed her, when they filled with soft warmth. His love for her was inexplicable and so strong; he sometimes felt overwhelmed by his fierce desire to protect her from the evils of the world in order to preserve her stringent sense of morality and fighting spirit. He imagined being forced to be away from her but loving her all the same and had to quickly shake off the feeling. It hurt too much to think about.

Tenzin looked at his father now, thinking about all that Aang had sacrificed for his family, all the while struggling to stave off his feelings. He was so strong, and in every way Tenzin's hero, despite this unexpected betrayal. There was something resolute and fiery in Aang's eyes, something Tenzin had never seen before. It looked good on him.

"I understand, Father," he said. "I just want you to be happy. If you believe this is the right thing to do, then I support you."

Aang's smile was like the first sign of sun after a stormy South Pole winter.