Fifty years from now, an elevated highway spans the nation. Initially a response to international terrorism, the U.S. government grounds commercial airline flights and builds the Black Diamond, a dangerous road full of gearheads and misfits, drug runners and grey-market tech heads, all driving illegal 1970s muscle cars in a nomadic, breakneck existence. But when the government decides to clean up the Black Diamond heading east and his wife is taken hostage by forces loyal to the road, Dr. Don McLaughlin has to borrow his brother-in-law's illegal 1973 Mercury Cougar to get on the highway and rescue his wife... 150 feet above and 100 miles-per-hour faster than anything he's ever known!