Last year Brazil's dreamers and builders launched a four-year programme to conquer the vast mysterious Amazon basin. Mechanised armies of bulldozers are slashing red-earth tracks through virgin rain-forest in an attempt to occupy the hinterland, but deep in the forest the Indians are fighting back with bows and arrows. Construction of Brazil's Great North Road, from Manaos to Georgetown, has been brought to a standstill by one of the most hostile tribes ever encountered. A BBC expedition by mini-hover-craft traces the route of the proposed jungle highway, from the Amazon to the Atlantic Ocean, and uncovers the strange story of a massacre in the forest.