The film tells the incredible true story of British explorer Percy Fawcett, who journeys into the Amazon at the dawn of the 20th century and discovers evidence of a previously unknown, advanced civilization that may have once inhabited the region. Despite being ridiculed by the scientific establishment who regard indigenous populations as savages, the determined Fawcett – supported by his devoted wife, son and aide-de-camp – returns time and again to his beloved jungle in an attempt to prove his case, culminating in his mysterious disappearance in 1925.