Conversely, this act, done under the influence of a soaring and iridescent Eros which reduces the role of the senses to a minor consideration, may yet be plain adultery, may involve breaking a wife's heart, deceiving a husband, betraying a friend, polluting hospitality and deserting your children. It has not pleased God that the distinction between a sin and a duty should turn on fine feelings.

- C.S. Lewis, The Four Loves

Chapter 1 - Secrets

I was seven years old when my sister Kya was born, old enough to start asking questions.

"Dad," I said, watching my father brush the spring shed out of his bison's thick white coat. "Do you think the new baby will be an earthbender?" A very logical proposition, to my childish understanding.

My father laughed and shook a clump of bison hair out of the large bamboo brush he was using. "No, Bumi," he explained patiently as he continued his task, brushing the darker fur on Appa's head. "She could be a waterbender like your mother, or an airbender like me." A half-shrug, and he added almost as an afterthought, "Or a nonbender like you."

"But you're an earthbender, too," I protested. I had seen my father bend all four elements - air most frequently, but water and earth often enough, and even fire if the occasion called for it.

"I'm the Avatar," my father clarified, though at the time I had little idea what that meant. "But I'm still an Air Nomad." Seeing my look of confusion, he gave Appa a placating pat on the head and came to crouch in front of me where I was seated on a bale of hay. "The Avatar can bend all four elements. But for anybody else, in order to bend an element, you have to have at least one parent from that nation."

I tilted my head slightly to one side, studying my father's face - open, honest, expecting some sign that I understood. But his words made no sense to me. "I don't get it," I admitted.

With a sigh, my father stood, patted my head much as he had done to the bison a moment earlier, then resumed his task, brushing Appa's flank. "Maybe it will make sense when you're older."

I picked at the hay I was sitting on, tugging loose a long stalk and twirling it in between my fingers. Maybe it would make sense one day, I thought. Or maybe, the unsettling possibility occurred to me for the first time, maybe my father was wrong. Maybe there really were things even he didn't understand.

Because I knew, though he didn't, that I could bend fire.

I was a late bloomer, six years old and no sign of bending, my parents already resigned that this was to be my fate. They never said as much to me, of course, but I could tell my father especially was disappointed. Children notice these things.

So the first time a flame danced to life in my hand, I was excited. My father was away on one of his many journeys, some important Avatar business, but I ran to show my mother, expecting her to share in my delight. I held up the little tongue of fire, cradled in both hands, full of innocent exuberance. "Mom, look what I can do!"

When she recovered from the initial shock, she smiled, but I could tell it was forced. Her eyes were not happy or proud, but afraid. Quickly I closed my outstretched hands into fists, snuffing out the fire, and drew back a little. "Is that bad?" I asked, worried that I had done something wrong, to upset her.

"Oh, no, it's not bad," she hastily reassured me, pulling me into a hug. "It's...it's very special, what you can do." If it wasn't a bad thing, why did she sound so sad? When she held me at arms' length, she was no longer even forcing a smile, but looked more serious than I had ever seen her before. "In fact, it's so special," she said carefully, "I think we should keep it just between us. Our secret."

I was a child. She was my mother. If she said it should be a secret, I trusted her completely. But still I asked, "Why?"

My mother took hold of both of my small hands in hers. "If other people found out…" she began, then considered her next words carefully. "Well, they wouldn't understand. Better you and I are the only ones to know."

"And Dad?" I asked, certain she would amend the new rules she was establishing to include him as well. Of course my father would know that I was a bender after all. That was all I really wanted.

But what my mother said next would alter the course of the rest of my life. "No," she replied firmly, her grip on my hands tightening. "No one else, not even your father. Is that clear?"

Stunned, I could only nod.

My mother hugged me again, and I clung to her, my one anchor in this new, frightening world I was to live in, where I was a firebender and my parents kept secrets from each other. When she spoke again, I think it was more to herself than to me. "Your father especially wouldn't understand."

It was a few weeks before my eighth birthday. My father was gone again - something in Ba Sing Se required his attention, I think, though he would make it back to Kyoshi where we still lived then just in time to give me my birthday present. I missed him when he was away, but there were little consolations. When he wasn't around, we ate more meat, and my mother would let me use my firebending for small, domestic things, like lighting a lamp, or starting the cooking fire.

But at that moment, I was not bending. My mother was mending a shirt I had torn, Kya was in her cradle swatting at the little figures of koi fish that hung over her head, and I was spread out on the floor with paper and a set of colored pencils my Uncle Sokka had given me. I showed about as much promise as an artist as Appa did at reciting poetry, but my uncle encouraged me nonetheless.

This particular masterpiece was to be a family portrait. I drew my father first - a tall stick figure with a blue arrow taking up most of his face, some vague orange scribbles for clothes. My mother was similarly attired in blue, with a brown braid sticking out from the side of her head. Next to her I drew myself, wearing a darker blue, and if the black lines sticking straight up from my scalp were an accurate representation of what my hair looked like, this was purely coincidental. Finally, I added Kya, though, uncertain of how to draw a baby, I simply made her a smaller stick figure with a single brown curl on top of her head.

Picking up the dark blue pencil again, I added some more squiggles next to my mother's stick-hands to show she was waterbending. I went back and forth over the proper color to draw air - which, after all, was invisible - before giving up and scribbling in a brown rock next to my father instead. After another moment's consideration, I added a red jet of flame in his other hand as well.

I looked at the red pencil in my hand, then at my own stick figure self.

"What a lovely drawing, Bumi!" my mother exclaimed, picking up the paper before I could come to a decision. "I think it's just missing one thing."

"What?" I asked eagerly, gripping the red pencil a little tighter.

"You should add Appa," my mother replied, holding the drawing back out to me with a smile.

"Nah," I said, tossing the pencil aside. "I don't know how to draw a sky bison." Besides, Appa was mostly white, and while I did have a white pencil, I had never known what use it was supposed to be on equally white paper. "I think it's done."

"Well, if you're sure," my mother said. I nodded, and she went to add the family portrait to the collection of my other masterpieces that adorned one wall.

Kya's little hand made contact with one of the koi fish, sending it swinging on its string, and she let out a giggle. "Hey, Mom?" I asked. "Do you think Kya will be an earthbender?"

My mother turned away from the wall of drawings and gave me a careful, searching look. "Where did you get that idea?"

"Well, Dad bends air," I began. He could bend all the elements of course, but I knew by then that air was special to him. "And you bend water, and I bend fire, so...earth's the only element we're missing, right?"

My mother sighed and went back to her seat by Kya's cradle. "That's not how it works," she said, picking up her sewing again. Unlike my father, she did not offer further explanation. So I asked.

"Well, how does it work? Because Dad said-"

My mother let out a sharp hiss, and I started, before I realized she had only pricked herself with her sewing needle. Still, the look she gave me this time was stern. "What did you say to your father?"

"Nothing!" I protested. I knew the rules, and hadn't done anything to give away our secret. "I just asked him the same question, if Kya could be an earthbender!"

My mother's face softened. She set the sewing aside, and held out her arms. Obediently, I got up and went to her, and she drew me onto her lap. "And he said no, of course," she guessed.

I nodded. "But I thought, since he doesn't know about me, maybe he was wrong," I confided in a small voice.

My mother hugged me tighter, and I rested my head on her shoulder. "No," she said, that strange sadness in her voice again. "Your father's right."

"But how do you know?" I pressed. I didn't want to wait until I was older to understand.

My mother ran one hand over my hair, then traced soothing circles on my back. "I just do," she replied. It was an answer I had heard her give before - when Kya wasn't born yet, and she'd insisted the new baby was a girl, and my father had asked her the same question - how do you know? She just did. My mother just knew things.

If there was more to it, I couldn't figure it out, and she wasn't going to tell me.

When I was eleven, we left Kyoshi and moved to what would later become Air Temple Island. Living just outside the newly-founded Republic City was supposed to make it easier for my father to attend to most of his Avatar duties without having to spend so much time away from home, which I was now old enough to realize was a point of contention between my parents. This worked out well for about three years, before Tenzin revealed himself to be a precocious airbender, and suddenly my father had to give him a traditional Air Nomad upbringing - which of course meant traveling the world.

But when we had just moved to our new home, and Tenzin was only a baby in my mother's arms, and Kya hadn't even begun to waterbend yet - that was when the Fire Lord visited us.

He brought gifts for all of us children - a fancy teething ring for Tenzin which my mother protested was too nice to let a baby chew on, a pair of dolls for Kya made to look like a little Water Tribe boy and girl, and for me a pai sho set. My father promised to teach me how to play the game.

The friendship between Fire Lord Zuko and Avatar Aang was already becoming the stuff of legend. They had spent the better part of the last decade working closely to found Republic City and transform the old Fire Nation colonies into the new United Republic of Nations, and the camaraderie between them was easy to see in person. But my mother was more distant with our distinguished guest, in a way that only struck me as odd at the end of his visit, when the Fire Lord hugged my father goodbye, and then, after the briefest hesitation, offered my mother a formal bow. Kyoshi Warriors or Air Acolytes, old friends or new acquaintances, my mother hugged everyone. But not him.

Yet what I remember most vividly about that visit is watching the friendly firebending match between the Avatar and the Fire Lord, the first time I saw real, powerful firebending on display. I had never seen my father bend like that before.

Tenzin was dressed like a proper Air Nomad child, of course, but Kya insisted on wearing blue, as we both had on Kyoshi - as most of the Kyoshi natives did, in spite of their nominal Earth Kingdom affiliation. After the move, I adopted new colors - grey trousers, and a red tunic, similar to the clothes the Air Acolytes wore. There were only a handful of them on the island in those days, but my father was always trying to recruit more, in between meetings with the Council of Nations and the other heads of state.

It was my mother who ended up teaching me to play pai sho. Unlike drawing, I turned out to be quite good at it.

Of course, as soon as Kya had gotten old enough to walk and talk and be aware of what was going on around her, my casual firebending had come to an end, even when my father was away. My mother and I didn't speak about it much - she always rose early in the morning, to get a head start on the day, and I soon began to feel the call of the rising sun. If we crossed paths in those quiet hours of the early dawn, she might whisper a question about meditation, or a suggestion about breathing techniques - just enough to keep my bending under control, and out of sight.

My father suggested I join the Air Acolytes for their daily prayers, and I often did, when he was there as well. The air temple was only a small shrine at that point, a square colonnade open to the four winds. I liked the serenity of it, the steady chanting of the mantras. I couldn't bend outwardly, of course, but as I carefully regulated my breathing in time with the prayers, it made me feel like there was a warmth in my stomach, a secret inner fire that was all mine.

But when my father was away, even just across the bay in Republic City for a council meeting, my mother discouraged me from spending too much time with the acolytes. I think she felt it was dangerous for me to get too spiritual. Perhaps she was afraid it would bring things out that she preferred to stay hidden.

Whatever her reasons, by the time I was thirteen, I had a daily routine. I would wake up, light a candle, and meditate in the privacy of my room, then head outside to watch the last of the sunrise, before retreating to the kitchen to help my mother with breakfast. If my father was around, we would join the acolytes for midday prayers. If not, which was more often, I would repeat the solitary candle meditation before bed. I had some sense, gleaned from my parents' stories and what I had read, that this was more or less how real firebenders did things.

Even then, I did not consider myself a real firebender. After all, I was special. Different. Strange.

There was no one moment when I discovered the truth, no sudden realization. It came to me gradually. But my father had been right about one thing - when I got older, I understood.

To bend fire, you had to have at least one Fire Nation parent. I could bend fire. My mother was Water Tribe. Therefore, my father had to be Fire Nation.

Therefore, Aang was not my father.

It was a distressing understanding to come to. Yet to my mother, the one person I could have talked to, I said nothing. The lies I had been made accomplice to as an unsuspecting child, the burden that had been placed on me to carry in secret, the loneliness of it, the way my own bending now reminded me of my mother's betrayal to the point that I came to hate it, the sting of Aang's indifference, knowing he wasn't even aware of how much I actually deserved it - how could a boy of only fifteen confront his own mother with all that?

So instead, I ran away. Let it never be said that Aang had taught me nothing.

I did not run very far. In fact, all I did was take the boat to the city. My mother had taken Kya and I there several times, but I had never gone by myself before, let alone without telling anyone where I was going. That made it sufficiently adventurous for my first foray into teenage rebellion.

Republic City was not then a large enough town to really get lost in, but it was bustling enough - so different from the serenity of the island, and yet the anonymity of the crowd was its own kind of relief. I walked the streets without purpose, listening to snatches of conversation and vendors calling out there wares.

A woman in green gossipped with a friend, "I heard the Southern Water Tribe is petitioning to have their own representative on the council, but none of the other nations get two…"

A boy my own age called out, "Yang's Noodle Bar, best noodles in town!"

An old man complained to a grocer, "I'm not paying that much, these mangos aren't even fresh…"

A well-dressed man beckoned to passersby to enter his shop, "Finest tailoring, ladies and gentlemen, right this way, latest fashions from all the nations…"

Distracted by the garish mannequins in the window of the tailor's shop, I bumped into someone, spilling the stack of fliers in his arms all of the sidewalk. "Sorry," I said quickly, stooping down to help him collect the papers. They were advertisements for a bending school.

The man I had bumped into was surprisingly good-natured about it. "You wouldn't happen to be looking for a firebending instructor, would you?" he asked as I handed him the last bunch of fliers. He shook the dust off of them and tucked them under his arm.

I panicked, wondering if he was a mind reader. "What makes you think I'm a firebender?"

The man mistook my fear for offense. "Sorry, son, didn't mean anything by it," he said with an apologetic bow of his head. "I just thought you might be, with how you were dressed and all…"

I looked down at my red Air Acolyte tunic, realizing for the first time that it would look rather Fire Nation, to an unfamiliar eye. "No," I said, shaking my head. "I'm not a bender." Then I hastily took my leave of him, making my way down the rest of the street hardly seeing or hearing anything else around me.

The street led me to a park, and I found a secluded spot by a willow tree to sit and collect my thoughts. I sat in a meditative pose, eyes closed, fists pressed together like the acolytes had taught me, and felt the warmth in my stomach - steady, persistent, but firmly contained. I wasn't looking for a firebending teacher - I had my bending under control, enough that I wouldn't accidentally hurt anyone, and that was all that mattered. I didn't want to be a real firebender.

So what was I looking for? What did I want?

It was getting late, and I was hungry. I had no money, and the only person I really knew in the city was Toph Beifong, who was the chief of police and a close friend of my parents. I hadn't thought through this whole running away thing. I wasn't even free of the secrecy here - I could still bend fire, but I still couldn't bring myself to tell anyone. Perhaps I should just go home and face my family and accept that this was my life.

I opened my eyes, cast a furtive glance around, and when I saw no one else, let a small flame burst to life in my cupped hands, just like I had first shown my mother. I knew now, why she had been upset, what she had been afraid of. If it weren't for my bending, I might never have known her secret.

But even unknowing, I would still have been the bastard son of some other father.

I heard footsteps approaching, and quickly snuffed out the flame. A voice called my name. It was Aang, the last person I wanted to see. I got to my feet. "Hey, Dad," I greeted him.

Aang gave me a once over glance, then, satisfied I was in one piece, put a hand on my shoulder. "Your mother's been worried about you," he said, only a mild scolding. I suppose, to an Air Nomad, my sudden flightiness didn't seem so unusual. "You should have told her where you were going."

"Sorry," I replied, letting him lead me out of the park. "I just needed to...get away for a bit."

Aang nodded as if he understood. "Next time, at least leave a note." And that was that. We made the rest of the trip back to the island in silence.

The Northern Water Tribe was having some difficulty in agreeing on a successor to the childless Chief Arnook, and called on the Avatar to resolve the dispute. This meant Aang was once again not around when I was about to turn sixteen, as he had not been when I had turned fifteen, or twelve, or nine.

I had just finished my morning meditation and joined my mother in the kitchen when she asked me what I wanted for my birthday. Since it was just the two of us - Kya always slept late, and Tenzin had gone with Aang - I gave her a true answer. "My father," I said, with glib spite.

My mother set the lid on the rice pot and gave me a pointed look. "You know they need him at the North Pole right now," she chided me.

"What about my real father?" I challenged her. "What's his excuse?"

My mother's face fell. She sighed, and smoothed her hands over her skirt. She must have known this day was coming, when I would finally ask. "He doesn't know," she said softly. Then she picked up a knife and cutting board, took a seat at the kitchen table, and began slicing pears. Her hands barely shook.

"What?" I asked, leaning on the table across from her. I didn't mean to loom over her, but I was a good deal taller than she was by then, even when she was standing. In fact, I was already as tall as Aang, and still growing.

"He doesn't know," she repeated, her eyes fixed on the fruit she was slicing. The knife made a sharp tapping sound against the cutting board. "I never told him."

"Were you ever going to tell me?" I asked. She hadn't even tried to deflect or protest her innocence, not that there would have been much point. I wasn't a small child anymore. She could no longer hide behind my naïveté.

My mother set the knife down. "I had hoped you wouldn't want to know," she admitted, her voice low. She squeezed her eyes shut. "I just wanted to forget my mistake, to pretend it had never happened…"

Her mistake. That was what she called it. Was that what she thought I was, too? I stood up straight, putting more distance between us. "But then I wouldn't let you forget."

She opened her eyes, and they were filled with tears. "None of this is your fault, Bumi," she insisted. "I never blamed you for anything." In hindsight, I think she meant it. But at the time, I was too angry to believe her, and too well aware of what a good liar my mother was.

I stormed out of the kitchen and back to my room, for the first time feeling like my fire might be in danger of slipping out of my control. I had been angry before, but it was a low, simmering anger, nothing like the desire I now felt to burn something, to let loose the flames and the truth and let them destroy what they would.

But I didn't lose control. Instead, I slammed my bedroom door, then relit my candle. Neither was a satisfying outlet. I found a pen and paper, and sitting down to write I let the words wreak havoc as my fire could not. You lied to everyone, I can't stand the sight of you anymore, I'm leaving, don't follow me, don't send Aang after me, I hate you.

It was certainly not what Aang would have had in mind, but I had taken his advice. This time, when I ran away, I left my mother a note.