Jones and Macintosh... Jesus, I already love those guys. o_o
Nav will be completely mad. But he's a good navigator so that's okay. (He doesn't tell his real name. Everyone just calls him "Nav".)
I don't know yet what the plot will be. But given that the world will be rather complex I'll spend a lot of time on just showing how their community works, what they do for a living and who their enemies are. If you can call "toxic air" an enemy, that is...
Apparently, I already came up with a way to injure Jones. Not that I'm sadistic. But I have this highly dramatic scenario in my head... and he catches a bullet and falls down into some ventilation shaft.
I should mention that the whole world is very very much destroyed and the air poison so... they live in huge machines, restlessly moving about the earth, looking for something. Anything.
Is it sad and depressing? Nope, actually it's going to be a lot of fun.