Scientist and explorer George Challenger learns from a dying colleague of a prehistoric world and organizes an expedition to find it.

Desperate to escape and more than a little greedy, Marguerite offers Veronica to a tribal chief in return for jewels and safe passage off the plateau for her group.

When Roxton is running from a tyrannosaur, the earth suddenly swallows him up; the party follows a river to an underground ocean.

Stung by a giant bee, Summerlee lies near death; Challenger seeks a way to repel an attack by the ape-men.

In order to free Challenger from her tribe, the team must retrieve the bones of a warrior queen's husband.

Christecs brand Summerlee a devil after he revives a drowning child.

A vampire bite elevates Roxton's hunting instincts to a bloodthirsty level; a smitten native will fight Malone to the death for Veronica.

Druids worship Marguerite, who bears the mark of an ancient prophet; Veronica and Summerlee find a baby.

A search for Veronica's parents leads to a paradise guarded by prehistoric creatures and filled with beautiful, talented immortals.

Roxton, Challenger and Summerlee bring badly injured Malone to a magic healer in order to save his life.

Challenger, Malone and Veronica are exploring ruins on a riverbank, when a man stumbles out of the jungle in a hail of deadly arrows. Malone drags the wounded man to safety, who dies in their arms issuing a cryptic message to find a man named Pierson Rice. Challenger recognizes the name as that of a vain glorious hunter whom Roxton once held in high regard. The trio send a message to Roxton and Marguerite, then hurry on in search of Rice. Roxton is disgusted to learn that his one-time hero may be alive and well. Arriving at a native village, our heroes discover that Rice is far from peril -- in fact, he has made the natives his loyal subjects. With the help of his cold-hearted lieutenant, Rice plans to eliminate the queen and marry her beautiful daughter to consolidate his power.