After the gang retrieved Aang from Zuko, lost Appa, and finally gotten to Ba Sing Se. They were clueless to know that Iroh and Zuko were there as refugees, starting a whole new life with a new identity. Since they were now wanted fugitives by the fire nation.
For weeks, Katara couldn't get Zuko out her mind. What he said to her just stuck with her for days on end. She could see in his eyes that he respected her as a bender. As Aunt Wu predicted that the man she would marry would be an extremely powerful bender. She could also see that in Zuko.
Zuko went through a big change after Jet got killed and he set Appa free from the prison under Ba Sing Se. Iroh was proud he had finally found his way. One afternoon Katara and Zuko got captured under the catacombs of Ba Sing Se by Azula, Mai, and Ty Lee. They had pretended to be Kyoshi warriors to sneak into the earth kingdom to take it over once and for all.
While Zuko and Katara were there, Katara was so angry. But you could just sense the chemistry under there. While she was mad, Zuko was sad.
"This is just a trap to get Aang! What is with you and wanting to capture the worlds last hope for peace?! Oh wait. You're the firelords son." Katara said angrily
"It's not a trap. I don't want my honor or the avatar anymore I've changed" Zuko said looking down
"You have no idea what this war has put me through personally! The fire nation took my mother away from me." Katara said sadly as she touched her necklace
"That's something we have in common" Zuko said sadly
Katara turned around and gasped. She had never known that he could've gotten hurt that way, being fire nation royalty. She could truly see the good inside of him. She stepped a little closer...
"You know when I thought of the face of the enemy, it was always your face that popped up" Katara said
"My face, I see." Zuko said touching his scar
"No I didn't mean it like that!" Katara said sadly
"No, it's okay." Zuko said
Zuko stepped a little closer to Katara. They were just gazing into each other's eyes. Katara finally offered to try and maybe heal it with the water she had gotten from the spirit oasis in the northern water tribe. Zuko declined the offer since he thought it couldn't be healed since it was a scar. Katara of course, still insisted.
She stepped even closer. Their clothes were rubbing together. She grabbed his face and just looked at him, she was looking at his lips and back at his eyes. Zuko closed his eyes and Katara started to lean in. He grabbed her waist and she still had her hands on his face. Their lips were almost touching until...
*BOOM*
Uncle Iroh and Aang bust in. Katara and Zuko step away from each other as fast as they can... You should know the rest of the story.
After the battle between Aang, Azula, Zuko, and Katara. It was the lowest point for Katara because she was the first one to trust Zuko. She really believed he had found his way.