A/N: Just thought I might give you a taste of what I've been working on lately (not that this is the only one but... yeah.) So... yeah, go nuts. Or don't. Anyway, please review and tell me what you think. It's unbeta-ed, so any mistakes are mine and mine alone (though I'd love it if you tell me).

Disclaimer: ATLA and Sherlock are not mine. I've just jumped the fence so I can have a dip in their pools.

Chapter One: The Next Avatar

Since the day Sherlock was born, his parents knew he was special. As he grew, it became apparent that he was very bright, simultaneously fascinated and bored with the world, as though it was his first day of life, but also his last. He adored the stories his father told him about men who could move mountains and breathe fire, and about beasts that flew through the air without wings and a creature the size of an island. Sometimes he would even tell him the ending to the story, despite never hearing it before. When he was seven, his mother taught him a very special form of martial arts that he couldn't talk about to anyone, but by now he was used to his parents' secretive nature. He knew with just a glance that his parents were hiding something, and it was little surprise when they told him about the secret history of their family. Water-benders had once been a proud people, living at the North and South Pole without fear. But the world changed and bender became a dirty word. Those with power were exiled or hunted, forced to hide their gifts and assume the guise of normalcy. The same fate befell the Fire-benders, the Earth-benders, and the remnants of the Air-benders. Every Avatar after this exile sought a way to reunite the people, and failed. A mysterious anti-bender group, known only as 'the League', desired the extinction of all forms of bending, and continue their witch-hunt even in the light of the modern world. Sudden raids on homes in the middle of the night, people disappearing for involvement in 'suspicious activities' and children being taken from their families. These were the signs. The Order of the White lotus does its best to help as many as they can, but it is a losing battle. Sherlock knows this, and he has known it since the day he witnessed a man, a Fire-bender who did nothing more than heat up a cup of tea, being dragged off in the middle of a crowded market with no objections. All they had to say was, "He's dangerous." The benders were losing ground, and they had been since the last Avatar, the very last of the natural Air-benders, died nearly four hundred years before. So when the Order came to visit his family home in the middle of the night when he was just eleven years old, Sherlock already had his answer to the question they would ask.

"No."

"Sherlock, you can't just say no, the world needs you." Mrs Holmes whispered hurriedly.

"It is alright, Mrs Holmes. Your son is young, and the world is not kind to those who are different. He already understands this, and it would be unfair to force such a burden on him. We will return when he is older to ask again, if he changes his mind. For now, we will allow him his childhood for a little longer." Jai Hyde, Grand Master of the White Lotus, answered smoothly. He looked directly into Sherlock's eyes, his faced lined with sadness, exhaustion, and fear. "Please, while we are gone, think of what your return would mean to the few of us who are left. Please. You are the only hope we have left."

The three members of the Order, old and weary and strong, bowed low to him. They murmured something in a foreign tongue, a prayer for his safety and his prosperity, and then they left. The only one to look back was Master Katherine Wayne, another Water-bender, and between them passed an understanding. When the time comes, you will do what is right.

Later, after his mother and father had tucked him into bed and read him another story, though he knew now that they were actually true stories, his older brother came to him. He didn't say anything at first, choosing instead to comb Sherlock's hair with his fingers, the way he used to do when they were younger. "Why did you say no, Sherlock? Why say no to that power? Why don't you want to be the Avatar?"

"Because…they want me to save the world. They want me to make it so that we don't have to be afraid anymore. But I can't do it. I can't fix the world, it's too broken. And I'm just a kid."

"Has mother ever told you the story of Avatar Aang?"

"No. But if I'm supposed to be the new Avatar, then he's one of my past lives, right?"

"Right. When Aang found out he was the Avatar, he ran away. Somehow, he ended up frozen in an iceberg with his Sky Bison. And they stayed like that for a hundred years. When he woke up, the world was at war and his people were gone, wiped out in a mass genocide. It was his duty to restore the balance to the world by defeating a Fire Lord, who was following his ancestor's example; he wanted to take over the world, and he was willing to kill people to do it. Aang was forced to master the elements in barely a year's time, so that he could stop the Fire Lord from committing genocide of the Earth Kingdom. And he did. He took away the Fire Lord's bending, and the world became peaceful once more. Aang was only twelve. If he could do it, why couldn't you?"

Sherlock narrowed his eyes suspiciously. "Did he really do all of that when he was twelve?"

"Scouts honour." Mycroft grinned. "I will admit that he did have a bit of help. He had friends from all walks of life, from all of the four nations, and together they saved the world." He dropped his hands from Sherlock's head, reaching for the ancient tome on the highest shelf. "Here, I'll show you, see?"

Sherlock studied the magnificently drawn image of a bald child with arrow tattoos, a group of comrades at his back, facing off against a tall, dark-haired man who was breathing fire. The caption proclaimed it, 'The Phoenix King Versus the Avatar: the Battle for the World'. He turned the page to find another picture: this one of the Avatar, his body lit with an almost holy light, pressing his hands to the Phoenix King's face, while in the background an older boy with a scarred face and a dark-skinned girl fought against what seemed to be lightning. This caption read, 'The End of the Phoenix King and the Rise of Peace'.

"That's Zuko and Katara behind Aang, fighting against Zuko's sister, Azula, for the right to become the new Fire Lord. Zuko and Katara won." Mycroft told him, pointing at each one in turn.

Sherlock squinted at the picture, making out the form of a girl amongst the lightning. "She could bend lightning?"

"Yes. It takes a deep spiritual balance, but potentially all Fire-benders could do it." Mycroft said, closing the book and putting it back on its shelf. He turned back to Sherlock, and kissed the child on his forehead. "Don't forget, Sherlock. You've done this a thousand times before, technically. I believe you can be the one who sets us free."

"Mycroft…"

"Yes?"

"Are you nervous? About your Water-bending assessment by the Order, I mean?" Sherlock bit his lip, not looking up. The assessment- an examination that would decide if the bender in question had the skill and talent to go on to try for Mastery and, later, a place amongst the Order –had been a sore, rarely spoken about subject since it had first been mentioned a few weeks before. Their mother had failed by exactly one mark, and since having her own children she had been determined to see that they would succeed.

Mycroft was quiet for a moment, fidgeting with Sherlock's blankets. "Not really. I've been training for a while, so it shouldn't be that hard. It's just that, if I pass, I might not come home."

"Why?"

"It's a long story, Sherlock. And you need to rest. I'll tell you about it later."

"Can't you give me the abridged version?"

Mycroft sighed. "They might send me far away, to somewhere like America or Australia, to be one of their operatives. I might have to fight members of… of the you-know-what. And I might die."

Sherlock patted Mycroft's cheek gently. "Don't worry, Mycroft. You're the best Water-bender there is. No one could hurt you."

"Thank you for the support, little brother. And I know you're going to be a great Avatar, the greatest that ever lived." Mycroft smiled, kissing his brother's forehead once more and leaving.

Sherlock lay back in his bed, cuddling his stuffed bear, and began to dream of a young monk leading him through a maze. He passed many people, who all seemed to know who he was, and saw creatures that defied logic. When he awoke, he forgot everything except the last word's of the monk, "No matter what you lose, no matter how much you suffer, you will always find your way to the right path. You are the Avatar."

d(^_^)b

Mycroft had passed his assessment and was pronounced a fully-fledged Water-bender, much to his mother's delight, the day after his eighteenth birthday. Despite his fears, he was not sent to parts unknown, but returned home to assist his brother's training. By his fourteenth birthday, Sherlock had mastered Water-bending, though he would not require an assessment (the perks of being the Avatar). The next night, his house was burnt to the ground and his parents were dead. It had been swift and sudden; twelve men in masks surrounded their house with torches, nailing boards across the doors and windows. Only one door was left unbarred, and it was through this a thirteenth man entered, murder his only intent. Mr Holmes, a non-bender who had enthusiastically immersed himself in his wife's culture, chose to defend his family while they went out the secret passageway in the basement. The intruder beat him mercilessly, and was about to strike the final blow when Mrs Holmes reappeared. They struggled, the woman desperate to protect her family, the man eager to wipe out another abomination. The man won out, overpowering Mrs Holmes despite her fantastic power, and knocked her unconscious. Before she succumbed to the darkness nipping at her mind, she used the last of her strength to fling the man from her home, back through the door he had come through. The twelve surged forward, barring the final door and setting the house alight, before disappearing into the shadows. Below ground, Sherlock and Mycroft crawled through a labyrinth of tunnels. It went on for hours, each straining to hear any sign of their parents following them. When they came to the end of the maze, Sherlock sat down and began to sob, his heart telling him what he hated to hear. But he had little time to grieve, as a member of the Order showed up to spirit them to the nearest safe house. Everything they had ever owned, bar their pyjamas and the Book of Legends that Sherlock had grabbed, was in ashes and their lives were in tatters.

Grand Master Jai paced the room, his brow furrowed and his heart heavy. Sherlock and Mycroft sat in two chairs before his desk, still in their bedclothes. Jai sighed, sitting across from them. "I'm so sorry, boys. We went as fast as we could but… it wasn't enough. We couldn't save your parents."

"What are we going to do?" Mycroft asked quietly.

"We must remove the two of you from the country, as soon as we can." Jai answered. "I have contacts in Australia who will be able to keep you safe, and teach Sherlock Earth-bending."

"Is that all you care about?" Sherlock yelled, leaping to his feet. "This Avatar stuff? You were meant to keep us safe! My parents trusted you!"

Jai's head bowed. "I am sorry, Sherlock. This is my fault and I should have down more to protect you and your family. One day, I hope you might forgive me. But for now, the best I can do is make sure you reach your full potential, and that you are capable of protecting yourself. Please, Sherlock, all I want is for you to be safe."

"Liar." Sherlock snarled, storming off.

Jai sighed once more, looking to Mycroft, who hadn't said a word since he arrived. "Mycroft, would you please go after your brother?"

Mycroft nodded and stood, his face blank and emotionless. Without enthusiasm, he left the room and followed his younger brother, quickly finding him curled up in a closet. "Sherlock, you're causing a scene." He said quietly.

"I don't care!" Sherlock sobbed. "Mum and dad are dead!"

"I know, Sherlock. But crying isn't going to bring them back. Nothing can."

"But it's impossible for me to not feel sad."

"Sometimes it isn't the actions of another that brings us down, Sherlock. Sometimes it's the pain and suffering we feel in our heart. In order to move on, you need to accept a simple truth: all things come to an end, and all hearts are broken."

"That sounds miserable." Sherlock murmured.

"That's life, Sherlock. All you have left is your destiny."

"And you." The young Avatar added, looking up with hope in his eyes.

Mycroft ran his hand through Sherlock's hair, more out of his own need for comfort than anything else. "I might not always be here. You need to prepare yourself for that day, because as long as I'm a bender, there will always be a chance that I might not see the next tomorrow."

Sherlock's face crumpled once more, the idea of losing his brother squeezing at his chest. "B- But what- what would I- I- I do without you?"

"I'll stay with you, as long as it's in my power to do so." Mycroft said, wrapping his arms around Sherlock's shaking figure. "I'm not just going to run away. But you need to prepare yourself for the day that I won't be here anymore."

Sherlock nodded, though he still clung to his brother. Mycroft helped him up and guided him back to Jai's office, where he curled up beside the fireplace and fell into an uneasy sleep. In his slumber, he heard snatches of the conversation around him, but it merely shaped his dreams. His mind conjured up scenes of dry desert and bushland and strange creatures that bounced around wildly. He ran through low bushes that scratched at his legs while the sun beat down on his pale skin, looking desperately for someone he couldn't remember.