Prologue: Post-World War Three
Humankind is at the brink of extinction, billions are dead. Several thousands are dying from hunger, from thirst, and from radiation poisoning. Entire cities have disappeared as an unstoppable force called "super nanobots" eat all the surface metal. These "superbots" eat a gram of metal and from that metal produce three new superbots. Only one hunderd superbots were unleashed, but at the end of the war, millions are around. The programming of these superbots limited the spread of the superbots but the superbots evolved.
They are smarter than humans and spread undetected by humankind. Soon, the superbots were all over the world, then all at once they became active and destroyed entire cities. These superbots soon became like sand-storms. Humans unlucky enough to be caught in these "nanosotrms" were stripped of everything but their bones. Because the nanos evolved to ingest everything in their path. They evolved past just eating metal on a large scale, but to the nanoscale of eating metal. So humankind's blood brought about their own destruction or near enough. Soon, though, all the surface metal was wiped off the face of the earth. The information passed from superbot to superbot and they went dormant.
Underground was a different story, though. Anarchy was spreading above and below ground and as the last act of the governments of the world was to launch every nuclear missile they had. The governments of the world decided on a mutual destruction. The Underground caverns were opened up, and huge missiles launched everywhere. Some people who had escaped the cities' major destruction were caught as bombs hit the land. Radiation poisoned the land and people. This was the death of humans and the Earth.
But human will and nature would not be stopped. Nature sent cleansing rain, let fire run rampant, let the air sweep up radiation to one area, let the Earth dump the radiation deep within itself. Nature saved humans.
Humans went to the brink and did not fall. Humans, though, still lost hope. Knowledge almost disappeared overnight. Radiation was still killing and mutating people. But slowly, in fact, countless generations passed and the radiation finally no longer affected people. Humankind struggled against nature to set up a new society and failed. Countless more generation passed and hope appeared. People were able to be one with nature. they controlled the earth, others air, others water, even the power of fire. People of Air lived in the sky, People of Water could withstand the pressure of water and lived underwater. People of Earth lived on the land, shaping it to their will. People of Fire, though, lived everywhere, having no place to call their own.
Thus here, the After Near Destruction story of humankind begins.