Irene Bobs loves fast driving. Her husband is the best car salesman in western Victoria. Together they enter the Redex Trial, a brutal race around the ancient continent over roads no car will ever quite survive. With them is their lanky fair-haired navigator, Willie Bachhuber, a quiz show champion and failed schoolteacher whose job it is to call out the turns, the grids, the creek crossings on a map that will finally remove them, without warning, from the lily-white Australia they know so well.