This 1959 work of fiction takes place in the same year it is published and is the story of a small town in north central Florida. The population of Fort Repose and the surrounding area is just under five thousand. Central characters in the novel are the Bragg brothers and their family. The older Mark is a career military officer. His brother Randy seems at first a ne'er do well lawyer and borderline alcoholic. Randy lives the carefree life of a wealthy old Florida family's younger son. Mark's premonitions and fears initiate the storyline but he is in only the spirit, hope and memories of his wife and children during most of it. Mark sends them to Randy in Fort Repose since Omaha is a primary Soviet target. Pat Frank narrates how nations destroy each other and themselves using nuclear arms. Randy Bragg leads a small band of survivors to remake a civilization with a stronger, deeper commitment to life and lasting value. Heroes and heroines develop in the struggle to survive amidst opposition from small-minded, weak-willed, greedy and selfish antagonists. Survival of the fittest rules Fort Repose but an invitation to depart is not accepted.

Mark's suspicions are correct. While his family is en route to the Orlando airport, Peewee Cobb flies patrol over the Mediterranean. He fires a heat-seeking rocket that goes awry. The errant rocket guides itself to a port used by the Soviets to harbor nuclear submarines and munitions. Conflict might have been avoided in previous years, but a change in Soviet strategy and tactics causes dire consequences. The explosion initiates immediate Russian retaliation which in turn causes United States counter-retaliation procedures to begin in Omaha and other SAC locations. Societies are destroyed and social structures rendered ineffective on both sides as a third world war begins on The Day. Fort Repose is an island of peace and relative calm in the contaminated zone of Florida. This is the tale of the extended Bragg family's ability to cope and successfully survive a feared nuclear holocaust.

Fort Repose society begins to break down at dawn on The Day as atom bombs drop on populated areas of Florida. An explosion occurs in south Florida and is followed by explosions in Jacksonville and then Orlando. Fort Repose is clear of fallout but is affected because the bombs destroy communication, electricity and replenishment of supplies from other areas. Virtually overnight, Randy Bragg sheds his alcoholic tendencies and ne'er do well lifestyle to become a family man, leader and eventual defender of the community. Lesser characters like the banker do not survive The Day when suicide is preferable to the assumed humiliation of financial collapse. Some hoard, rob and murder at the same time others share, help and lift the spirit of their compatriots. Alas, Babylon is the story of a civilization that disintegrates when external supports fail. Fort Repose remakes itself on a smaller, localized and more natural scale with a stronger, deeper commitment to life and core values. Heroes and heroines develop that overcome the small-minded, weak-willed, greedy and selfish. When an opportunity to depart Fort Repose is presented, no one asks to leave with Colonel Hart's helicopter.