The Zones- extra dimensional planes of existence directly corresponding with our own world, and populated by an ancient race known only as the Natives. As mankind threatens its own existence with warfare and pollution, so too are the Zones affected, shrinking ever smaller as a result of the havoc wrought upon Earth.
Now, the livable space of Manhattan's Zone 27 grows dangerously constrained, forcing the Natives ever higher into the skyline, and two nigh-immortal champions compete in an invisible war for dominance--but the consequences of their conflict could shatter not only the stability of the Zone Continuum, but also that of reality itself!
Just about a 4 as this is a very original and interesting concept, even if the fundamental plot-line is quite a standard one. The Dar live above the city, pollution forcing them upwards, their technology sustaining them. The detail in this invented tech is both imaginative and a bit overdone, in my view. Still, better than under-thought work.