In hindsight, he should have known this might happen. If Azula managed to break into Ba Sing Se and stage a coup, of course she'd find out about the invasion sooner or later. He'd played right into her hands, bought the bait, wasted their time. And all for something he hadn't even realized all along when it should have been clear as day the moment he saw Azula and her friends in Kyoshi Warrior garb.
Sokka sighed, glancing up at the moon. It's always been like this, hasn't it? Every time he said the universe hated him he was just complaining, but now he wondered if maybe it was true. Yue, Suki, his father...he'd failed them all, one after the other.
Yue's sacrifice had been her decision, but it didn't change the fact that Sokka had promised and failed to protect her from having to do it.
He'd failed to make the connection between Azula in Ba Sing Se and Suki not being there until it was too late and the city fell.
And now, his father was being hauled off to prison where they would probably torture him on a daily basis.
"I'm the Avatar, if anyone's to blame for all this it's me," Aang kept insisting. But the invasion hadn't been Aang's idea. Aang hadn't helped create a weapon the Fire Nation would eventually use against them. Aang hadn't let Azula bait him and waste their time.
Sokka buried his face in his hands; tears stung his eyes but he refused to let them fall. Tears wouldn't turn back the clock and change the results of the invasion, they wouldn't bring back the dead, and they wouldn't free the imprisoned.
"I'm sorry," he mumbled, "I'm so sorry. To all of you."