Andrew Marr talks to the Swedish poet, Lars Gustafsson about whether writers have a responsibility to challenge the establishment. Gillian Tett, the award-winning Financial Times journalist, who predicted the financial crash, does her own challenging of the status quo. The writer Patrick Wilcken describes the great intellectual Claude Levi-Strauss, as 'the poet in the laboratory' in a new biography. And Ed Vulliamy reports, in almost anthropological detail, on the lives of those caught up in the war of drugs, gangs and guns on the US-Mexican border. Producer: Katy Hickman.