Nike's Chariot

It was the end of the world.
Or was it?
It had started out like any other day. In fact, it was quite beautiful, not a cloud in the sky, balmy and just delightful. It was a perfect day for a picnic or playing in the park.
However, that wonderful weather didn’t last very long. The sky suddenly filled with angry, swirling green and black clouds, which quickly transformed into snarling and twisting tornados. Strange blue lightning sizzled overhead, before incinerating people and buildings alike.
Yet there was something else involved in this apocalypse, this final cataclysm. Strange black winged shapes that moved faster than sight or sound, zipped in and out of the destruction. Some thought they looked like evil dragons. Were they to blame for the final day?
In desperation, humanity fled in any direction, escape their only motivation. They died by the droves, scores of people swept up in the insanity of complete chaos, many killed with society’s collapse, at each other’s hands. As all of civilization was erased by powerful forces unimagined by any of them, a handful of citizens made it to safety.
Thirty lives were spared that day, not by the firepower of our armed forces or law enforcement, but by a simple coin, a medallion cast from an unknown metal. On the surface, the goddess Minerva’s likeness was cast.
That eerie, ear-shattering sound will never be forgotten. They remember it in the quiet hours and it haunts them in their sleep. The indescribable horror of such noise echoes in their souls and will forever change their perception of what really happened that day.
Faced with too many questions and no apparent answers, an intrepid band of 12 hand-picked explorers sets out on an expedition to seek supplies and perhaps other survivors. Even more so, they seek the truth of what really happened that day.
What they find instead is nothing but more questions. Yes, it was obvious that all signs of people have vanished. The countryside has been torn apart by nature gone mad, but was there something more sinister at work? Through Alabama, Mississippi, Louisiana, and Texas they travel, encountering one challenge after another. Turning north, they cross Oklahoma, Kansas, Nebraska, Wyoming, Montana, and into South Dakota, resolutely heading towards the abandoned Black Hills Ordnance Depot, where Minerva’s Shield was first uncovered.
Shocked by yet another unforeseen discovery, this hardy band of adventurers is thrown into the middle of a global conflict that defies explanation.
It was the end of the world.
Or was it?