Thousands of years after a catastrophic event destroyed civilization, mankind has adapted and evolved new ways of surviving. Today, giant mobile cities roam the earth, relentlessly devouring small traction towns. Tom Natsworthy (Robert Sheehan), from the lower echelons of the big traction city of London, is forced to start fighting for survival after an encounter with the dangerous fugitive Hector Shaw (Hella Hillmore). Two diametrically opposed people who should never have met are accidentally allied, and they are destined to change the future.