A Random

SCIFI.radio story

Earth encounters a group of time-traveling tourists on a sightseeing trip to the past who want to plug us into a power grid and use us as living batteries even though they can all do credible singing impressions of Ethel Merman who derive their sustainance by a nuclear bomb , but scientists create a new weapon which turns them into weird rocks.
The End.and then they kill us all.
The End.