Bill Markham (Powers Boothe) is an engineer who has moved to Brazil with his family to work on a large hydro-electric dam. The film opens on Markham, his wife Jean (Meg Foster, his young son Tommy (William Rodriguez), and his daughter Heather (Yara Vaneau) having a picnic on the edge of the jungle, which is being cleared for the dam's construction. Tommy (William Rodriguez) wanders from the cleared area. An Indian (Rui Polanah) from one of the indigenous tribes known as the Invisible People notices Tommy and abducts him to protect him from the destructive builders. Markham pursues the pair into the forest but does not find his son.
Ten years later, the dam is nearing completion. A 17 year old Tommy (Charley Boorman), now called Tomme, has become one of the Invisible People. Tomme marries a woman named Kachiri (Dira Paes) and undergoes a vision quest, where his spirit animal tells him he must retrieve sacred stones from a remote spot deep in the jungle. Chief Wanadi, the man who abducted and adopted Tommy, warns him that the quest will be dangerous, as it will take him into the territory of the cannibalistic Fierce People.
Meanwhile, Markham has finally identified his son's abductors. Markham and a journalist decide to set off bottle rockets to attract the attention of the Invisible People. Instead, they attract the Fierce People and are captured. Armed with a CAR-15 carbine, Markham is able to defend himself long enough to talk with Chief Jacareh (Claudio Moreno) who releases Markham for the night, promising to hunt him down in the morning, while the Fierce People kill and butcher the journalist. Close to dawn, Markham stumbles into Tomme collecting the sacred stones. The two recognize each other just as the Fierce People arrive, shooting Markham in the shoulder. Tomme and his father manage to escape, leaving Markham's carbine behind. In the care of the Invisible People, Markham recovers from his injuries and undergoes a vision quest, waking up back at the dam's construction zone.
Jacareh, recognizing the destructive power of Markham's carbine, visits a seedy brothel at the edge of the construction zone and arranges to exchange women for ammunition and more guns. Tomme and his friends return to their village to discover that many of the Invisible People have been murdered and all the young women abducted by the Fierce People. Desperate for help, Tomme navigates the city to his parents' condo, and Markham agrees to help rescue the women from the brothel.
That night, Markham initiates a shootout in the brothel while Tomme and his friends release the enslaved women from captivity. In the ensuing battle, the Fierce People kill several members of the Invisible People, including Chief Wanadi. Tomme is later sworn in as the new chief of the tribe. Markham warns Tomme that the almost-completed dam will end the tribe's way of life, but Tomme insists that the Invisible People are safe. During a storm, Markham places demolition explosives at key points along the dam, blowing it up.
The film ends with Tomme and Kachiri sitting at the swimming hole near their village in the jungle, watching the members of their tribe splash and play.Powers Boothe as Bill Markham
Meg Foster as Jean Markham
Charley Boorman as Tomme/Tommy Markham
William Rodriguez as Young Tommy Markham
Estee Chandler as Heather Markham
Yara Vaneau as Young Heather Markham
Dira Paes as Kachiri
Eduardo Conde as Uwe Werner
Ariel Coelho as Padre Leduc
Peter Marinker as Perreira
Mario Borges as Costa
Átila Iório as Trader
Gabriel Archanjo as Trader's Henchman
Gracindo Júnior as Carlos
Arthur Muhlenberg as Rico
Chico Terto as Paulo
Claudio Moreno as Jacareh
Rui Polanah as Wanadi
Maria Helena Velasco as Uluru
Tetchie Agbayani as Caya
Paulo Vinicius as Mapi
Aloiso Flores as Samanpo
Joao Mauricio Ca as Monkey
Isabel Bicudo as Kachiri's cousin
Patricia Prisco as Kachiri's cousin
Silvana de Faria as Pequi
Rotten Tomatoes gave it an 87% rating, out of 13 reviews. The Emerald Forest was designated a Critic's Pick by the reviewers of the New York Times. It was nominated for 3 BAFTA Awards, for Cinematography, Make Up, and Score.
The film was promoted as "based on a true story". Critic Harlan Ellison in his book Harlan Ellison's Watching wrote that attempts by the SCAN library reference/research company to get background information on the real story revealed that Rospo Pallenberg's original screenplay was based on several stories, including an article in the Los Angeles Times about a Peruvian labourer whose child had been abducted by a local Indian tribe and located sixteen years later almost fully assimilated. Pallenberg's agent told SCAN that while Boorman claimed to have read the original Times article, he hadn't, but was simply working from Pallenberg's screenplay. According to SCAN, Boorman told NPR's All Things Considered that the son was still living with the tribe in 1985 and identified the tribe as "the Mayoruna", yet detailed anthropological studies of that tribe do not mention an adopted outsider.
However, a contemporaneous January 1985 review in Variety magazine states up front that the movie is "[b]ased on an uncredited true story about a Peruvian whose son disappeared in the jungles of Brazil." This fact demonstrates that the source of the film script was known at the time of release. The Los Angeles Times article also mentioned that the Peruvian child had at the time decided to stay with the tribe.
Another potential source for The Emerald Forest is the book, Wizard of the Upper Amazon, by F. Bruce Lamb. The story is a second hand account of Manuel Cordova's kidnapping when he was a teenager working for rubber cutters in the Amazon in the early 1900s. He was taken by a group of Indians to a very remote Indian village. These Indians were of a fierce independent disposition, and had fled into the interior because they refused to exist in the subservient situation imposed on them by the rubber barons of that time. Cordova was incorporated into their tribe and describes a life strikingly similar to the one depicted in The Emerald Forest.
The film ends with a message: "The rain forests of the Amazon are disappearing at the rate of 5000 Acres per day. Four million Indians once lived there. 120 000 remain. A few tribes have never had contact with the outside world. They still know what we have forgotten."