A band of adventures sets off to prove the existence of dinosaurs deep in the forest of the Amazon. After an unfortunate accident leaves them stranded, they must put their trust in a jungle girl to save them from the dangerous predators on the plateau.

Marguerite makes a deal with a local chieftain to get off the Plateau. The deal is to hand over Veronica to the chief for marriage, something she wants no part of. Like all such schemes, things don't work out as planned and the team must fight a variety of threats in order to save the chiefs daughter, Veronica's virtue, and their own necks.

In this episode, Challenger, Summerlee and Veronica save a little girl from drowning and Summerlee has to give her mouth to mouth resuscitation. Tolmac, of the Christec people, brands Summerlee a witch for bringing the girl ""back to life."" The Christecs have mingled the Catholic and Aztec religions, with a touch of Conquistador Inquisition, to form their theocracy. Veronica gets away to summon help from the others, but Challenger has to act as Summerlee's lawyer ~ if found guilty, both men will be burned at the stake.

While wandering the plateau, Roxton is attacked by a young man, who bites him during the struggle. Roxton's infected with a disease whose symtoms are slightly bizarre ~ intense craving for blood, pain when exposed to sunlight, a powerful feeling of kinship with nature and ""creatures of the night"" - he is as a vampire. He runs mad and into the gothic mansion of Calista, a beautiful woman with the same disease. Back at the treehouse, a young native man, Niko, comes forward, declaring his love for Veronica. He and Malone argue and decide to fight to the death for her; she is not pleased! Outside the treehouse, Malone and Niko do start to fight, but quickly stop when Veronica tells them she will kill herself to stop them, and has a knife at her stomach to prove it. Niko leaves, but tells her he'll never forget her. Veronica remains mad at Malone for a while for trying to fight her battles. In the meantime, Marguerite and Challenger discover all about the disease, and search for Roxton, not

Challenger is trying to harness the energy of lightning when a gigantic bolt splits the sky. In a blinding flash, the ground is scorched, and by some miracle, no one is injured. In the silence after the thunder, the sputtering sound of a small engine is heard, and a small plane appears in the distant sky. It drops from view, crashing into the jungle. All survive: four modern day tourists - a couple, a middle-aged man and a gorgeous young woman. The group are set upon by a hostile tribe and taken prisoner. Our explorers arrive to find only the disabled plane, which Challenger and Malone set about trying to repair. Kenner, the leader of the hostile tribe, is fascinated by his captives but keeps them in a dungeon. Roxton and Veronica devise a plan to save them.

A mysterious old woman, a shape-shifter, appears to Veronica, convincing her that her lost parents are safe in El Dorado. The woman gives her the directions to its entrance in a rock wall, and warns that she must tell no one and can never return. When Veronica unwittingly releases a savage giant from captivity, Marguerite and the others must use all their talents to subdue him again.