The conductor doesn't seem to notice him or his screaming or his spear. What Sokka, in turn, doesn't notice is the boots pounding against the tracks, quick as a seaside breeze, and the figure that breaks into the last car of the train. It's trying to get to him, breaking through windows and climbing through, trying to get to the first car where Sokka is.

The sign changes again.

They never needed you.

There's a blank space in the tunnel again, as the train rolls down the tracks.

The lights on the train flicker mostly out now, so that in between the light of the illuminated signs, there are stretches of total darkness. The whispering gets louder and louder, and occasionally, he can hear snippets sadistic laughter.

Sometimes when the lights flicker and for a moment, he sees Azula's face staring back at him in the darkness, but more alarming than her being there is that she disappears again right after. She's teasing him, maybe? Waiting for the moment to strike. Or maybe something is using her to tease him.

Is a blast of blue fire going to come out of the dark and end it all just like that?

The signs start up again.

Your sister will need someone...

Black black black, there is no moon here to shine light down on him, a comforting presence, no stars.

But even if you were there, you wouldn't be able to save her.

And then the sign changes for a stretch to an absolutely grotesque picture, a body arms held up in defense of itself, face caught in a rictus of terror.

Do you remember what your mother looked like, when your family found her body, Sokka? It hadn't been as awful as it could have been. It was the Fire Nation after all. Fire...could be destructive, and so many... so many died messily, at their hands.

...Have you ever stopped to wonder what your sister would look like that way? Messy?

You'll never leave. She'll die alone. Enjoy the ride!