[He gives a meek and nervous laugh to the first statement. The more he thinks about it, the more he gets really, really unsure about how to handle this whole thing.]

I'm not really sure. I don't know the full story. [And probably won't unless Zuko appears again.] I do remember Katara said once, that he mentioned to her once that he lost his mother because of his dad. But the last time I saw Zuko at home, it sounded like Zuko thinks she's alive. She's just... missing, for some reason. And no way he's tried of finding her has worked. But he thinks that'll be the key, to finding peace as the Fire Lord.