Nick and Sheila Blackstock become lovers just prior to the detonation of a nuclear electromagnetic pulse bomb in outer space above North America. The high altitude detonation destroys every microchip in every electronic device and produces the complete meltdown of the entire electric grid, casting the population of the United States back to a time without electricity. Swiftly, Nick and Sheila, in the company of Ron Doris Steele, revert to a life resembling the primitive frontier days. Hardy men and women travel on horseback, defend themselves valiantly and effectively, and take up residence in caves. Steffen and Courtney Decker turn their cattle ranch into a fortified refuge from the predatory thieves that abound in a land in which government and law enforcement has ceased to function. Eventually the two families join forces in the fight for survival.