Ed Stafford attempts to walk the navigation of the Amazon river. Ed faces the prospect of completing the mission solo when both his companion and his guide threaten to quit the expedition. As the journey progresses, Ed encounters wary villagers, murderous drug traffickers and deadly wildlife.

Having reached the halfway point, Ed and Cho still face the prospect of at least another 12 months of trekking across dangerous terrain. Another Brit decides to join the mission, but can he keep up with the intrepid pair as they face hunger, disease and parasites in the depths of the jungle?