While flying through a storm over the Amazon Forest, flight 767 to Rio de Janeiro suffers a shot circuit in its cargo deck and starts to lose height. Moments later, one of the wings is struck by lightning and the pilots are forced to crash land in a small clear. The tail section of the plane is cut off and slides down a cliff. The next morning, a rescue team searches the crash site, but they can't find any survivors. Since many of the passengers were Americans, the team is made up of American Rangers. Two of them find the tail section, but there is nobody inside, dead or alive. One of the rangers is attacked by piranhas and other is killed by a native, so the colonel in charge decides to call off the rescue. A Brazilian official objects, claiming that one of the passengers was famous opera singer Pia Claire and her body has not been found yet. The colonel says that since all the bodies are badly burned, he can pick up one and claim that it's Claire's.

Lost in the forest, the survivors try to gather some wood to start a fire. Will catches a glimpse of himself on Pia's hand mirror and notices that he has a strange simbol painted on his forehead. They search for food and find that someone or something is stalking them, but it turns out to be just a wild pig. Soon later they come across Marcel DaSilva, another survivor of the crash. Marcel has a deep knowledge on how to survive in the forest. He tells them that they must find a river and follow its course to the sea. It will be difficult, he says, but eventually they will find their way back to the civilization. However, moments later Marcel is bitten by a poisonous snake and dies. The survivors decide to go on with his plan anyway. Will sees a misterious blond man who has in his forehead the same simbol he has in his, but the man quickly disapears. When he tells the others, they think that what he saw was probably just an animal, but the blond man keeps following them...

Going back to salvage items from the wreck, the survivors encounter a wild jungle man and then find they must hide from natives who are apparently trying to kill them.

Karen, Pia, Jimmy and Will are taken to the native's village, where they find out that Sidney is still alive and has been kept as a prisoner since they last saw him. Back in the forest, Alex and Andrew discuss what to do. Andrew has leukemia and is getting weaker, so Alex wants to leave him behind and try to find some help. Andrew, in spite of his condition, wants to help the others. When the natives force Karen, Pia and Jimmy to take off their clothes (not all of them, actually) Jimmy hits one of the natives and is tied up with Sidney. Later, two wounded natives are brought in and the shaman performs some sort of ritual on them. During the ritual, Sidney is untied and the natives let him go, but as soon as he leaves the village, the natives start to chase him. He runs for his life, but he is soon caught and killed. Alex decides to join Andrew in his rescue attemp. On their way to the village they meet the blond man who was following the group.

The English-speaking jungle man brings the exhausted survivors back to his home, the village of the Chosen.