Katara tells them about seeing her mother through the mists. But she doesn't tell them about seeing the little Fire Nation boy, tears streaming down his face as he pleads for his mother. She doesn't tell them about seeing a smaller version of herself across from the boy, mourning her own loss. And she doesn't tell them about watching the boy grow until a horrific, familiar scar mars the left side of his face.
"The swamp shows you what matters," Huu tells them. "What you love." He stares long and hard at Katara. "The swamp don't make mistakes, little lady."