Carson is on the East Coast when the electrical grid goes down. Desperate to find Beatrix, a woman on the West Coast who holds his heart, he sets off along a cross-country railroad line, where he encounters lost souls, clever opportunists and those seeking salvation. Meanwhile, Beatrix and her neighbors begin to construct a cooperative community, working to turn the end of the world into the possibility of a bright beginning.
 
Without modern means of communication, will Beatrix and Carson be able to find their way to each other? The answer may lie with one 15-year-old girl, whose actions could ultimately decide the fate of the lovers.
 
THE LIGHTEST OBJECT IN THE UNIVERSE is a moving story about adaptation and the power of community, imagining a world where our best traits, born of necessity, can begin to emerge.