The Portuguese word sertão means ‘hinterland’ or ‘back country’, and in Brazil it refers to the inland forests, deserts and mountains far from the cities that line the Atlantic coast. Someone who has explored those regions is known as a sertanista, and the greatest living sertanista is Sydney Possuelo. Now 82, he holds the Bolsonaro regime responsible for the murder of his fellow sertanista Bruno Pereira and the British journalist Dom Phillips in the far west of the Amazon last month.