Thunder City presents Detroit in the process of becoming the Motor City. Harlan Crownover, scion of a great family of carriage makers, battles with his father to invest in a company run by Henry Ford, who has failed twice before in the automobile business. Desperate for funds, Harlan turns to Big .Jim Dolan, the Midwest's most powerful political boss, and Sal Borneo, a visionary mafioso struggling to bring the commerce of vice into the new century. Allies at first, they soon will be mortal enemies. At the crisis, only Edith Hampton Crownover, Harlan's troubled, aristocratic mother, will be in a position to shift the balance of power.