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

Roxton, Marguerite and Malone are mapping a series of caves, trying to find one that leads off the plateau without much luck. Marguerite, all the while, has been gathering gleaming gemstones in her backpack. At least she will not go back empty handed. A fog begins to fill the air around them...dense...deep fog. From out of the mist forms take shape: cloaked figures and eerie rock formations, encircling a stone slab. They find themselves surrounded by Druid-like figures who swarm over Marguerite. Roxton tries desperately to protect her, but she is torn from his grasp. The two men are restrained and Marguerite is carried away and deposited on the stone slab. It turns out that Marguerite figures in an ancient prophecy and that her fate has finally caught up with her, here. What it means, she must discover for herself, but it involves retrieving a sacred jemstone. She, along with Roxton and Malone, must go through several obstacles like headhunters and a leap of faith to accomplish Marguer

The aged guide who brought Veronica's parents to the Lost World dies in Challenger and Veronica's arms, humming ""Ode to Joy,"" leading the explorers to seek out a hidden paradise, where Veronica suspects her parents might be.