Aang sat on Appa's fluffy head, he and Sokka feverishly scanning the ground for a figure in blue or some water doing something unnatural. They needed to find Katara. They had to. All they had seen so far was the green of the forest, not even sign of an encampment. No smoke floating up from the trees, nothing.
Sokka looked down once more before saying, "Aang it's no use, we've been searching for hours. She clearly doesn't want to be found, and there's no way she could have gone further than this without Appa. I think we should just go back up to the temple and forget this ever happened, keep training. I know it'll be hard, but if Katara doesn't want to be found, there's no way we can find her." Sokka's face was expressionless, but Aang could tell that inside he was fighting not to cry.
"Sokka don't say that! We have to find her! We can't just leave her!" Aang exclaimed, the tears now flowing from his eyes, "I love her Sokka!"
"I know. I do too," Sokka said, his face still stone, "but I think this once, we have to let her go." Aang tried to choke out another protest, but his throat closed up and he just nodded. He couldn't bear to lose Katara, but if she thought it was safest to be away from everyone, and didn't want to be found, Aang would respect her wishes, no matter how painful that might be.
Aang sharply jerked the reins the opposite direction, turning Appa around to return to the temple- without Katara. Tears were flowing freely from Aang's eyes, realizing that he would probably never see Katara again. He kept scanning the trees though, hoping maybe just maybe Katara would appear in his line of sight. But she never did. He turned his eyes back to their destination, and as he did he thought he saw a flash of blue. Aang quickly turned his head back again, only to find that it was just his mind playing tricks on him. He looked back at Sokka sitting in the saddle and found that tears were silently creeping down the cheeks of the older boy. Katara was truly gone.