Archaeologist Dr. Pete L. Masters arrives in Manaus, Brazil, eager to visit the city museum, which displays treasures from the nearby Amazon jungle. He is delayed, however, by a local man named Crespi, who regales Pete with tales of a hidden jungle society, ruled by Amazonian women who possess a fortune in diamonds and gold. The good-natured Pete expresses interest, but when Crespi demands $5,000 to finance a trip to the Amazon tribe, which he claims briefly enslaved him thirty-five years earlier, Pete demurs. The next day, Adhemar Silva, the head of the local archaeology institute, shows Pete around the museum and describes an excursion four years earlier to the area of the jungle in which Crespi claims the Amazons dwell, which resulted in the disappearance of botanist Gina Vanni. Pete’s interest is piqued when he later reads about the legend of Amazon Queen Conori. Consequently, when Crespi arrives with a pure gold statue he insists is from the tribe, Pete, eager to investigate for himself, offers Crespi a position as guide. Crespi, who knows Pete cannot find the area without him, tries to demand control of the outing, but Pete asserts his dominance over the expedition. Over the next few days, Crespi gathers a boat, crew and supplies, and rebuffs Fernando and Carlos, ruffian brothers who want to join the crew to gain access to the rumored riches of the Amazonians. Pete and Crespi then set sail, only to discover Fernando and Carlos trailing them with a boat full of thugs. Soon, the brothers ambush Pete’s boat, and when Pete refuses to allow Crespi to return gunfire, they are overtaken. The brothers knock out Pete, leave his crew behind and take over the boat. When Pete regains consciousness, Fernando and Carlos lie that Crespi masterminded the ambush. To prove his innocence, Crespi attacks the brothers and, with Pete, jumps overboard and escapes into the jungle. Pete, feverish from malaria, soon collapses, and Crespi leaves him behind while he searches for help. When Pete revives, he is surrounded by women who are painted in green camouflage and holding spears. The Amazons take him to their village, where Gina, who has been kept captive there since her expedition, tends to him. The women, who run their society without the help of men, are fascinated by Pete and vie to bathe and clothe him. Fleeing from their prying eyes, Pete wanders into a room that contains a caged tiger and Mario Delano, the erstwhile leader of Gina’s expedition. Mario feverishly threatens to kill Pete, explaining that the Amazons will only allow one man to live, in order to repopulate. He fears and loathes his captors, who kill all male children and drug Mario to keep him docile and delirious. Pete, who scoffs at the idea that “a bunch of women” could harm him, promises to save Gina and Mario. Gina then enters and urges Pete to return to his room. When they are interrupted by a warrior who aims a spear at them, Gina urges Pete to seduce their assailant, and soon the warrior embraces Pete with enthusiasm. Later, Pete is brought before Queen Conori and her court. Although he refuses to drink drugged wine, the women intoxicate him with the vapors of a burning herb, then seduce him. The next morning, Fernando and Carlos land nearby, alerting the Amazons, who enter the jungle en masse to hunt them down. Realizing all the guards have left, Gina frees Pete from his room and they race through the village, spotting Mario’s murdered body along the way. In the jungle, they stumble upon the dead bodies of Fernando’s whole crew, but manage to elude the Amazons by camouflaging themselves. After swimming through snake-infested waters, Pete and Gina hide on an island. Pete soothes Gina’s fears that the Amazons will find and kill them, but is unsure of how to return to the mainland. Just then, Crespi flies by overhead in a rescue plane, and manages to spot the pair on the island. Days later in Manaus, Pete and Gina refuse to tell authorities about the Amazons, despite Crespi’s protestations and the tale’s potential to earn Pete fame and fortune. Forever connected by their ordeal, Pete and Gina plan their new lives together.