The Emerald Forest (1985)

Synopsis
The Emerald Forest is based on a true story, as related by Los Angeles Times correspondent Leonard Greenwood. Powers Boothe stars as a US engineer working on a dam project in Brazil. Boothe's young son (played by director John Boorman's son Charley Boorman) is kidnapped in the rain forest by a tribe called "The Invisible People" because of their skills at camouflage. The authorities give up the boy for lost (he's hardly the first abduction victim in the region), but Boothe and photographer Uwe Werner (Eduardo Conde) persevere. When Werner is killed, Boothe goes on alone for several years. He eventually stumbles upon the Invisible People and finds his son, but the adventure is just beginning. ~ Hal Erickson, All Movie Guide