The figure helps, pulling at them with his bare hands. His gasps of breath are a small clue of how painful that actually is. He's successfully helping Sokka rip them off, but it's cutting up his palms in the process.

Up ahead in the car, the spider-conductor hisses and starts towards them, and the spirit trains pulls away from the real train entirely and starts to thunder down the tracks, passing another empty station as it does.

That orange glow is getting closer and closer...

"You can tell your master that he doesn't belong to him! None of them do!" the figure shouts at the spider-conductor as he and Sokka clear off the last of the webs, and then he grabs Sokka by the arm and pulls him along towards the window he crashed through.

"Run run run run run!"

They have to get through all four cars of the train and out the back. It's their only chance of successfully jumping off without slamming into a concrete wall at incredible speed. Fortunately they can escape the same way Sokka's rescuer crashed his way through the doors and windows between the cars.

Or they could, at least, if the poles and bars of the train would stop trying to wrap around them and trip them up.