[What does he say? He could tell Aang that he's done his best. Or that he'll find a way. Or something. But that's probably what Katara's told him. And Sokka is a little more... realistic than that.]

That's how it is here. Sometimes you can protect people, sometimes you can't. It's great when you can, but you learn to live with it when you can't. I don't want to see her hurt anymore than you do, but... [A breath. He looks at Aang, instead of outside.] You have to be ready when it happens.