A nuclear cloud suddenly appears on the horizon, plunging the peaceful small town of Jericho, Kansas, into complete chaos. A large part of the United States has been exposed to a nuclear disaster. The residents of Jericho, completely isolated from the world, wonder if they are the last surviving Americans. With all communication and energy activities halted, the fear of the unknown creates a state of total social, psychological, and physical chaos in Jericho. However, during times of crisis, unexpected individuals can discover a strength within themselves that they never realized before, transforming into heroes.