A/N: I've wanted to write an AU/what if? Maiko story for awhile now, so here goes. Any fans of Full Metal Alchemist (if you haven't seen it, I recommend it highly) will recognize the phrase that makes up my title. Nothing can be gained without giving something up. Mai will find that out. Feedback would be wonderful. Do you like the idea or not, etc. Thanks for reading.

Equivalent Exchange

Chapter One: In the Blink of an Eye

Everywhere in the capitol city of the Fire Nation, citizens were whispering about what had happened to Prince Zuko. He had been shamed utterly and would bear a scar for the rest of his life to remind him of that shame. Mai shuddered at the thought and then shuddered again thinking about the pain her only true friend must be in.

As she made her way to the palace in hopes of seeing the prince, people turned to look at her. She kept her head high and met shaking heads and pitying glances with a cool, hard stare. With her back straight and her arms hanging loosely by her sides, Mai moved with the grace of a young woman trained to walk just so from the moment she took her first stumbling steps. Her simple red dress fluttered in the warm breeze and she smoothed down the fine silk out of habit. Mai could feel many pairs of eyes following her progress toward the palace. It felt like a hole was being bored through the material of her dress and then through her skin, her muscle, her bone. Taking a deep breath, she resisted the urge to turn around and thought of the prince instead.

Zuko was more than her friend. He was her betrothed; Mai was only twelve and the prince thirteen but their lives had been linked since toddlerhood when the royal family had approached Mai's parents about their daughter. Eager to make any connections that would benefit them, Mai's mother and father had practically given her up, body and soul to Prince Ozai and Princess Ursa, Zuko's stunningly handsome parents. It was just Ozai now, and he was the Fire Lord, but until last night, Mai had still been betrothed to Zuko. She wondered where exactly everything stood; she wondered how things had changed.

The very idea of arranged marriages offended and angered her but they were an integral part of noble life. If you weren't betrothed, people assumed there was something wrong with you. And if you complained about your assigned husband or wife, you were chastised severely or worse. There really was no getting around them unless you abandoned your family and ran away.

Mai was fortunate that she liked her betrothed. In fact, though she was still a young girl, she knew that she loved Zuko. She wanted to be with him, not because of his position or rank, but because he was the only person in the entire wide world who cared about her and what she thought and what she felt.

The young girl quickened her pace when the palace gates loomed tall and foreboding in front of her. She was almost desperate to see Zuko, to see just how bad the damage was and offer whatever comfort she could. The guards nodded respectfully to Mai and opened the giant gate, part of the wall that surrounded the palace, designed to keep unwanted people out and the royal family safe. Once inside she broke into a dignified run, stepping lithely along stone paths until she reached the palace's main entrance. More guards stepped aside for her and she walked into a cavernous foyer, sparsely decorated with the occasional huge vase or tapestry. Despite its bareness, the space gave the sense of tremendous wealth and dignity. The floors were of the finest polished marble and an exquisite scarlet runner trimmed in gold ran down the centre and followed all the palace's many corridors. The spirits of previous Fire Lords and Fire Ladies, princes and princesses seemed to hover over everything, a perpetual presence; or maybe it was just the life like portraits that lined so many walls.

Now that she was inside the palace, Mai wasn't sure where exactly to go. Would Zuko be in his room or with the physician somewhere else? She couldn't just stroll nonchalantly down to the residential wing alone. That would be considered improper. And suppose she did; would she even be allowed to see him and would Zuko want to see her?

Mai stood still, looking and listening. Part of her hoped for Azula to happen along. The princess would know exactly what was going on. Nothing but silence greeted her, however. Sighing she made her way toward the War Room, the place where this entire mess had begun. Guards and servants were the only people she saw. The servants eyed her strangely and Mai eyed them right back. Finally she decided to stop a woman carrying a tray with a glass of water and what looked like some kind of medicine.

"Do you know where Prince Zuko is?" Mai asked curtly.

The servant looked distraught and hesitated before answering.

"He's in his room, my lady," she finally said.

"How is he doing?" Mai asked in a hoarse whisper.

"I, um, he's in a lot of pain, my lady."

"Oh," Mai replied stupidly.

She wasn't sure how to respond to that. The servant took the opportunity to scurry off and Mai was left alone again.

Zuko's room was dimly lit and the prince lay on his back in the centre of his large bed. Almost the entire left side of his face was covered with loose white bandages and his mouth was set in a tight grimace. His uncle Iroh sat on the edge of the bed and placed a cool cloth to the bare side of the boy's face. The older man's expressions changed from anger to sorrow to concern and back again as if he was replaying the events of the Agni Kai and its aftermath over and over again in his head.

"Uncle," Zuko croaked. "What's happening?"

"You're safe now, nephew. I'm here to take care of you."

"Where's father?"

"He's out in the hallway," Iroh stated, hoping his words were true. "I'm sure he'll be in to see you soon."

"I'm sorry," the prince muttered. "I'm sorry, Father."

"You've nothing to be sorry for, Zuko," Iroh whispered.

The sound of the door opening interrupted the quiet conversation. Ozai strode over to the bed. He wore a smirk along with his Fire Lord robes and looked down at his injured son disdainfully.

"I've come to a decision," Ozai began. "In addition to the mark you will bear on your face and the humiliation you suffered in the arena, you are hereby banished from the Fire Nation never to return."

Iroh gasped and then opened his mouth to protest.

"Surely you can't mean it," the retired general said. "He's your son. He's a good boy, Ozai. He doesn't deserve that."

"You were always too soft on him, brother. And look what that has brought him. He needs to learn his place and he needs to do it somewhere else."

"Father," Zuko said feebly, tears streaming from his undamaged eye and a look of terrible sadness on his face. "Please, don't…..I'll do anything."

"The decision is final," the Fire Lord said in a clipped tone.

"You've given him no hope," Iroh continued. "He needs something to work toward, some way of getting back home."

"Fine," Ozai acquiesced and then thought for a moment. His lips twitched as though he were holding back a laugh. "If you find the Avatar and bring him to me, your honour will be restored. Until then, I, and everyone else in this nation will consider you a disgrace, a prince with no honour and no place in our fine nation. Out of the goodness of my heart, I've decided to provide you with a ship. You are to leave by tomorrow at sunset. Is that understood?"

"One day you will regret this, Ozai," Iroh said with a shake of his head. "One day…."

"Do you understand?" the Fire Lord bellowed, ignoring his brother's words.

"Yes, Father," Zuko said quietly and then buried the good side of his face into the coolness of his pillow.

Mai paced in a circle outside the palace library and considered her options. Finally, leaving caution behind, she set off for the residential wing. When she turned a corner, Mai almost ran into Azula.

"Mai," the eleven year old princess declared with a cold smile. "What are you doing here?"

'You know damn well what,' Mai thought but gave Azula a tight smile instead.

"I've come to see Zuko."

"Oh," Azula replied. "I don't think that's a good idea."

"What do you mean?" Mai asked.

"He doesn't want anyone in there besides Uncle Fatso. And I don't think you want to see, Mai. The left side of his face, almost all of it, was burned really badly. He's going to have a terrible scar."

"I don't care," Mai stated firmly. "I just want to see him. He's my betrothed."

"Not any more, he isn't," a voice boomed from down the hallway. "You no longer have any attachment to my son. I'll send a letter to your parents tomorrow, Mai."

"I don't understand," Mai said.

She looked between the Fire Lord and his daughter, waiting for an explanation.

"Zuko is banished," Ozai replied bluntly. "He won't be coming back to the Fire Nation unless he captures the Avatar."

"But the Avatar hasn't….."

"…been seen for a hundred years," Azula giggled. "We'll never see Zuko again. Oh, Father, that's a perfect punishment."

Azula walked with Mai to the palace's front doors. The princess's face was bright and shiny looking, like she'd just received the most wonderful gift. In fact, she had. She had no love for her older brother. She thought him inferior in every way and now that he was gone, she would take her rightful place as the deserving heir to the throne. Zuko's banishment was the best thing that could ever happen to her.

Mai was stunned into silence. Her pale hands were inside her wide sleeves and she felt for the blades that she always carried. They were her only comfort. She wouldn't get any from Azula and she wouldn't get any from her parents. Mai felt horribly alone and a dull ache throbbed in her chest.

"I can't believe my father's giving him a ship. What kind of hardship is that?" Azula mused. "Mai, I asked a question."

The black haired girl stayed mute.

"Fine, be that way. I'll see you later," Azula huffed.

Mai wandered home in a sort of daze. She couldn't imagine her life without Zuko in it. It seemed that she would have to get used to the idea. It was out of her hands, like so many things were. She was tired of having no control. She was tired of everyone making decisions for her.

"Oh, Mai, you're home," her father stated calmly as the girl walked through the front door. "You look upset."

"I wonder why," Mai snarled in reply.

"Now, now, dear," the bearded man said as he patted her shoulder. "We'll find you anther young man."

"Don't you get it?" Mai asked. "There is no one else. I want Zuko."

"Perhaps the prince should have considered you before he decided to dishonor his father and show a complete lack of respect."

"His father burned half his face off," Mai retorted. "What kind of man does that?"

"Mai," the man snapped. "You will not disrespect our Fire Lord in this house. He gave Zuko a lesson; one he will never forget. He was within his rights to kill the boy. But he showed mercy."

"Mercy," Mai spat. "Zuko's been banished too and can't come back unless he captures the Avatar….the Avatar, dad. It's an impossible quest. He's doomed to wander the world for the rest of his life. How merciful is that?"

"He's within his rights," the man repeated. "And he's our lord."

"I'm going to my room," Mai announced abruptly.

She was disgusted with her father, Azula, the Fire Lord and the whole damn nation.

"You'll feel better tomorrow," her father said brightly. "Don't disturb your mother when you go upstairs. You know what she's like when she gets one of her headaches."

Mai marched up the stairs, deliberately stomping on each one before entering her room and slamming the door. Her father sighed at the bottom of the steps and went back to his office.

The afternoon sun poured in through the large window that covered an entire wall of her room. Mai closed all the shutters, blocking out the offending light and dropped down onto her bed. She finally let the tears she had been holding fall freely. When she had cried herself dry, Mai began to think. A plan began to formulate in her mind. Maybe she wouldn't lose Zuko after all.