Following a cataclysmic conflict known as the Sixty Minute War, the remnants of humanity regroup and form mobile "predator" cities. Under a philosophy known as Municipal Darwinism, larger cities hunt and absorb smaller settlements in the Great Hunting Ground, which includes Great Britain and Continental Europe. In opposition to Municipal Darwinism, an Anti-Traction League have developed an alternative civilization consisting of "static settlements" in Asia protected by the Shield-Wall.