"Why would I let go of Katara?!" asked Aang. "I love her! Three chakras ago, that was a good thing!"
Guru Pathik frowned.
"That girl is not yours, Aang," he said sternly. "She is not anyone's."
Aang could see Katara- by the lake drying her hair, when he had first seen her coming out of the iceberg, standing with some sort of guy in a mask?
"I love her," Aang repeated obstinately.
"You have a duty to the world, Aang. Mastering the avatar state is something which every avatar before you has managed, as essential as mastering the four elements. It is your destiny to defeat the Fire Lord, and this is imperative to that end."
"It's Katara- I can't not love her, she's so-"
"You love all your friends, Aang," said Guru Pathik, pressing. "What is the difference with Katara? Why is this the problem attachment?"
"I don't know!" said Aang.
"I know," said Guru Pathik. "It is because you think that she is yours. But it is like I have said- she is not your girl, she is simply a girl. That is the difference."
"I know that she's not some sort of- belonging!"
"You know it in your head," said Guru Pathik, tapping his temple with one ancient finger. "But not in your heart. You understand it, but you do not feel it. Meditate on this, Aang."
Aang felt strangely sad. Loving Katara had only made him happy- how would he feel to let go of it? It seemed like a horrible thing to do.
"You still do not understand my meaning," said Guru Pathik. "You will still know this girl after you have mastered the avatar state. You will still care about her. The feelings that are worth preserving will stay. Jealousy and ownership will go, and leave something purer in their wake. Meditate, Aang."
Aang shut his eyes and meditated. Images of Katara came up again, floating to the surface of his mind. The fury on Katara's face when Master Pakku had refused to teach her, and then her cold determination to prove him wrong. Her wide grin when they went penguin sledding. How peaceful and serene she seemed when she stirred the soup they were eating for dinner, occasionally pausing to smell the aromatics. Then one that he hadn't seen before: Katara walking up to the Kyoshi warriors in Ba Sing Se, about to deliver a love letter…
"Katara's in trouble!" Aang had his eyes wide open again.
"You will best be able to help her when you have mastered the avatar state. Meditate!"
Aang's tattoos began to glow a vivid, peaceful blue. The avatar state was his.
"Well, she attended some war meetings with our generals, and then she's been off with your friends the Kyoshi warriors," said King Kuei. "Believe me, if there were any trouble, Bosco's animal instincts would sense it."
"See, Aang? The girls are probably at the apartment right now, talking about makeup or something," said Sokka.
"I guess," said Aang half-heartedly. But there was a filmy layer of dust over every surface when they went to check the apartment. And a knock on the door, which Toph went to answer.
"Zuko?" gasped Katara. She had been alone in the crystal catacombs, and she hadn't been expecting company. "Why did they put you in here?"
"Azula discovered Uncle and I," said Zuko. His voice was rough, like he'd been inhaling smoke. "The Earth King invited us to the palace, but it was a trap. Uncle made it free."
"Do they know about the blue spirit?" asked Katara, without a second thought.
"I don't think so," said Zuko. He looked exhausted.
"Why would your sister ever imprison you? When I saw that she was here, too, I thought you'd both been colluding- to capture Aang or something," said Katara.
She still thought it might be a trap. Aang would come to try and rescue her- that was as clear as day- and then Zuko would have easy access to him. But he'd had easy access for months without taking advantage of it…
"We're not on good terms," said Zuko. Katara raised her eyebrows without thinking about it, and Zuko continued- "Even when we were young, we never got along. I was my mother's child. She was completely Father's. Always."
Katara still didn't understand.
"You can guess who gave me this scar," said Zuko quietly. "There's only one person with the authority to burn a prince. And to banish him, too."
"I thought it was a training accident," said Katara, gaping. Without thinking about it, she rushed forwards to hug him. It was even more surprising that he let her. She had her head resting on his shoulder, and he seemed to radiate warmth. Maybe it was a firebender thing.
He tentatively put his hand on her back, and they were only like that for a minute before they heard a loud noise.
"Katara!"
"Aang!"
"We've come to rescue you," said General Iroh.
"Let's get out of here," said Katara, waving Zuko forward. But they were interrupted a moment later.
"Well, well, well, Zuzu," said Princess Azula. "I never thought I'd see you fraternizing with the enemy."