Zuko was thrown off the throne after the new Ozai society brought fire lord ozai back on the thrown and he was lost at sea till he turned up at the southern water tribe. Katara lived in the southern water tribe after Aang was killed by ozai. She wondered what happened to zuko but today he turned up,she was called to the dock and the water tribe soldiers had a tall man with long black hair,it was zuko. It wasn’t the boy katara knew,he was probably 25 or 26. He looked at her “katara?” He smiled weakly,his whole body was incredibly weak. He leaned down and kissed her gently