SAS legend Chris Ryan and undercover reported Donal MacIntyre take on the vast and impenetrable rainforest of Guyana. They'll have to hunt and forage their own food or they'll go hungry. They spend just 24 hours together, during which Chris helps Donal set up camp. By the heaviest rains in living memory make everything difficult; any firewood is sodden, flooded rivers make fishing impossible and prey animals head for the high ground. On day two, Chris leaves Donal and sets up his own camp deeper in the jungle. Without food or company, Donal's mental and physical condition deteriorate. Chris's new location is even harsher than the first - there aren't even palm trees from which to gather palm heart and maggots. Instead Chris resolves to get a fire going and keep it burning through four days and nights of torrential rain. But gathering wood from further and further away takes its toll and by day five Chris is forced to eat some of his emergency rations. Aware that his motivation is ...