Ozai was six years old the first time Iroh realized his baby brother was a genius.

At nineteen, Iroh was being groomed for his first real war campaign, to make his mark on the world before he inherited the throne. He was looking forward to it eagerly, ready to win fame and bring honor to his nation, but he was also the sort of man (the sort of boy) who enjoyed his leisure too much to throw himself wholly into war.

Which was how he came to be sitting in the shade of a tree in the palace gardens attempting to pluck out a tune on the pipa that fine spring afternoon. The music tutors of his boyhood had never had much hope for him, and they had long ago been replaced with generals and strategists to teach him more pressing skills for a future Fire Lord. But Iroh enjoyed playing nonetheless, when he got the chance.

A few paces away, Ozai was practicing the basic firebending forms he'd just begun learning that year. His stance was atrocious, his movements jerky and uncoordinated, and at every false note Iroh struck he would shoot his older brother a withering glare. It was adorable.

As Ozai began the kata yet again, Iroh plucked out a series of discordant notes on purpose, just to see what he would do. With a frustrated growl, the little boy marched up to him and snatched the instrument from his hands.

"The stupid song isn't even that hard," Ozai grumbled at him. "Watch." He adjusted the tuning of the strings slightly, then proceeded to play the complex piece Iroh had been fooling around with from start to finish, flawlessly. When he was done, he shoved the instrument back into his brother's hands.

Iroh was flabbergasted. "Ozai," he said proudly, "I had no idea you'd been practicing so much on the pipa."

"I don't need to practice that," Ozai scoffed. "It's not hard."

"Then you are a musical prodigy!" Iroh exclaimed with a chuckle.

"Whatever," Ozai replied. "Why don't you go make noise somewhere else now."

"Will you play for me again some time?" Iroh asked, undeterred by the boy's sour attitude.

Ozai seemed genuinely confused by this request. "Why?" he demanded. Ozai never asked, he always demanded.

"Maybe you can teach me how to play better," Iroh suggested, "and I can help you with your firebending. Would you like that, my little dragon?"

Ozai only scowled at the nickname. "I don't need help from you!" he insisted. "And I told you to stop calling me that!"

Iroh shook his head as Ozai stalked out of the garden in frustration. His little brother was far too serious for a child of his age, and always protested at being teased. That was, of course, all the encouragement Iroh needed to keep doing it.

Ozai was fifteen when Iroh realized his brother was hopeless with girls.

Iroh himself had never had such problems. Though happily married now, he had been something of a flirt previously, and could still charm the ladies of the court with ease. He supposed being the Crown Prince was something of an advantage, but even so. Ozai was pathetic by anyone's standards.

His brother's crush on the daughter of the governor of Nakajima province could not be more obvious. He loitered in corridors whenever her father brought her to court, stood straighter when she looked in his direction, and was at least twice as likely to trip over himself or drop something whenever he was in her presence. A simple "Good day, Prince Ozai," from the girl was enough to turn him as red as his formal robes. He was plainly besotted.

And yet, here they were at the royal ball to celebrate the new year, and there was the object of Ozai's affections, clearly waiting for someone to ask her to dance, and what was his brother doing? Sulking in the corner and staring at her from afar. Honestly, Iroh wondered sometimes how they could be related.

Taking pity on the boy, Iroh decided to intervene. Leaning casually against the wall next to Ozai, he said, "What a party! Are you having fun, little dragon?" But the hated nickname didn't even get a rise out of his brother, who merely grunted in response and kept up his one-sided staring contest with the girl. "You know," Iroh continued in a conspiratorial tone, "you could ask her to dance."

Ozai started and looked at him, as if he hadn't realized how obvious it was who he had been staring at. Spirits help this boy… "What?" Ozai scoffed. "No I can't."

"Of course you can!" Iroh insisted. "It's easy! You just walk up to her and say, 'Good evening, Lady Ursa. Would you like to dance?' Nothing to it!"

Ozai rolled his eyes. "And then what?" he said sarcastically.

"And then you dance with her," Iroh replied, ignoring the sarcasm. "And you talk to her, and you have fun. You've heard of fun, yes?"

Ozai glared at him. "What would I even talk to her about?"

Iroh shrugged. "Compliment her, ask her about her interests." He snapped his fingers as he thought of another idea. "Or talk about your music! Girls love that sort of thing."

His brother's glare softened from angry to merely skeptical. "Really?" he said. "You're not just making fun of me?"

Iroh placed one hand over his heart, and held the other up in a salute. "I swear on my honor as Crown Prince of the Fire Nation that I am not making fun of you, and that you had better march your royal butt over there and ask that pretty girl to dance before someone else does."

Ozai shoved him, and Iroh walked away with a laugh. He kept an eye on his brother, though, and a minute later he saw Ozai square his shoulders and mouth the words Good evening, Lady Ursa. Would you like to dance? to himself once, then twice. Then he took a deep breath and strode across the ballroom to the girl in question.

"Good evening, Lady Ursa," Ozai said confidently. Ursa looked up at him with a hint of a smile. "Dance with me," Ozai demanded. Ursa blinked in surprise.

Iroh sighed and held his face in his hands. His brother really was hopeless.

Miraculously, Ursa did agree to dance with Ozai, and as Iroh continued to observe them throughout the night they actually seemed to have struck up a real conversation. He was pretty sure Ozai only stepped on her feet once or twice, and succeeded in making her laugh on at least once occasion. More impressively, the young lady seemed to have coaxed his brother's elusive smile out of hiding by the end of the dance. What a relief that was - neither Ozai nor Ursa had any idea, but behind closed doors their fathers had already begun arranging the marriage.

Ozai was thirty-five when Iroh realized how much his brother hated him.

He had largely stopped treating Ozai like a child when Lu Ten was born, his own son proving a much more amiable object of all his affectionate teasing than his little brother had ever been. And certainly once Ozai had children as well, it was easier to see him as a fellow man, fully grown.

It was how Ozai treated his own children that opened Iroh's eyes.

He doted on little Azula, praising her and showing her off whenever the opportunity arose from the moment she was born. The girl was high-spirited and precocious - walking before her first birthday, running not long after, speaking in articulate sentences by two, and already showing signs of being a firebender when she had not yet turned three. Ozai could not have been more pleased with his daughter, and he made sure everyone knew it.

But to Zuko, his firstborn, Ozai was cold and distant. Unlike his sister, Zuko was a timid and sensitive child. He was respectful of his elders and strove to please his parents in all things, and he was certainly his mother's pride and joy. But his father, who was so liberal with praise for Azula, never seemed to find a kind word to spare for him.

The dutiful elder child and the prodigious younger sibling. It was obvious whom Ozai favored, and it occurred to Iroh for the first time that his brother might feel he needed to settle an old score.

Zuko was ten years old when Iroh realized how much his nephew took after his father.

He found his niece and nephew in the palace gardens. Azula was running away from her brother, holding a bamboo flute in her hand, which Zuko tried several times to snatch away from her, unsuccessfully. Neither of them saw their uncle in the shadow of the colonnade that surrounded the gardens.

"Give it back, Azula!" Zuko cried, making another grab for the instrument.

Azula yanked it out of his reach once again. "Should you really be wasting your time with this, Zuzu?" she taunted. "I think your firebending could use some work."

"That's none of your business!" Zuko protested, stamping his foot. "And stop calling me that!"

Across the garden, on the other side of the colonnade, Iroh saw his brother. Ozai met his eye, but made no move to intervene in his children's argument. There was a hint of something cruel, a dark satisfaction, in his face. It made Iroh uneasy. He took the initiative to come to Zuko's aide instead, striding into the garden and taking the flute from Azula's hand before she could protest.

"What a lovely instrument," he said appreciatively. "Do you play, Azula?"

His niece scoffed. "Not willingly."

"Then I think you have no need of it," Iroh concluded, looking Azula sternly in the eye. "And you may as well let your brother have it."

Azula pouted for a moment, then shrugged. "Sure," she said, turning to leave. "Who wants a stupid flute anyway." She ran to her father, who put a hand on her shoulder and led her away. Ozai spared one last dark look at Iroh as they left.

Iroh handed the flute to Zuko, who was scowling at his feet, clearly embarrassed. He still managed to mumble a thank you to his uncle.

"I would like to hear you play," Iroh said, seating himself underneath a nearby tree. "Your mother says you are quite good."

Zuko rolled his eyes. "Of course she says that." But he put the flute to his lips obligingly and fulfilled Iroh's request anyway. Iroh recognized the tune quickly - it was an old folk ballad, which started out simple and gradually grew more complex. He'd never been able to master it himself in his youth, but Zuko hit every note, never faltering, never squawking awkwardly as children so often did with the wind instruments. His eyes were closed in concentration, no need to see as his fingers deftly felt their way to the proper holes on the instrument.

The music carried him away for a moment, and Iroh could easily have been thirty years in the past, watching another gifted little boy play in this very garden.

When his song was finished, Zuko opened his eyes in time to catch Iroh wiping away a tear. They boy's face fell. "Was it bad?" he asked nervously.

"Oh no, Prince Zuko," Iroh said solemnly, taking the boy's hands in his own. "It was beautiful. You are very talented."

Zuko beamed at him as Ozai never had.