The city is San Francisco. "Not long after" refers to a devastating worldwide plague that has wiped out most of the planet's population.
The people who survive in San Francisco are mostly artists, hippies, and misfits who pull together a viable community and transform the city. But when a military general determines to reunite the remnants of the once great United States and sets his sights on San Francisco, the people resist, believing they have already discovered a better way of life. The new and artistically creative guerrilla warfare they stage will make for one of the oddest battles ever fought.
