The Tropic of Capricorn cuts through Southern Africa, Australia, and South America, and Simon Reeve follows it across four episodes, tracking the line through Namibia, Botswana, South Africa, Mozambique, and Madagascar before continuing into Western Australia, the Northern Territory, and Queensland, then on to Chile, Argentina, Paraguay, and Brazil. Reeve treats the latitude as a thread through very different problems rather than a scenic route: he visits Swakopmund's German colonial architecture in Namibia, looks at AIDS rates and poverty across southern Africa, and follows the effects of China's growing appetite for resources in the countries he passes through. In Australia the film turns to the outback and its remote communities; in South America it takes in the reach of Brazil's economy and the pressures on the region's environment. Reeve narrates in the first person throughout, talking directly to farmers, miners, and local officials rather than relying on outside experts, so each stop reads as an encounter rather than a postcard.