The Last Vimana

According to ancient Sanskrit writings, thousands upon thousands of years ago, ancient human spacecraft know as Vimana once flew to the planets in our solar system and beyond.
Something happened, possibly a global nuclear and scalar weapon holocaust and the ensuing climate and sea level changes wiped out almost all traces of that fallen civilization.

In my imagination, one military vimana pilot refused to carry out his destructive orders and instead saved his crew mates and ship from the devastation. Returning to Earth, he found there was no civilization left to return to. He spends the remainder of his life doing what he can to help and rescue some of the few survivors and eek out a living by learning how to live of the land and was among the survivors who had to start from scratch.

I remember a quote from Einstein which went something like:

"I don't know how world war three will be fought, but world war four will be fought with sticks and stones"