A one-off documentary in which survival expert Ray Mears offers actor Ewan McGregor the chance to go on a trek of a lifetime. The star of Trainspotting and Moulin Rouge rises to the challenge and joins Mears on a trip deep into the Honduran jungle, accompanied also by explorer Dr Chris Begley of the University of Kentucky. After just a few basic lessons in survival, the team set off in search of a lost civilisation. How will McGregor cope with all that the Central American rainforest throws at him?