Marguerite Krux (Rachel Blakely)
Mid-thirties, mysterious, wealthy. Marguerite never knew her parents. Raised in a succession of boarding schools, with dimly-remembered guardians caring for her trust fund until she came of age, she was given the finest education - but no love. She has an extensive and eclectic knowledge on a variety of subjects, an incredible facility for languages, and no scruples whatsoever. She will do anything, betray anyone, if it advances her cause.

Marguerite funded the explorers' mission on the condition that she came along. She believes she's been driven to fund the project because of her desire for wealth - particularly for precious jewels. But in truth Marguerite is driven by something she doesn't understand and can't control. It's almost genetic; it frightens and mystifies her, but she would never show that fear to others. It's as if her whole life has been in preparation for this journey into the Lost.

Edward (Ned) Malone (David Orth)
Early 20's, American. Now a reporter, Malone started out as a newspaper boy, selling papers on the street. He became a copy boy, then saw his chance to move up quickly by becoming a war correspondent during the Great War. It was there he learned to travel by balloon.

Malone is not, by nature, a courageous man. However, he is more afraid of being thought a coward than anything else - and it's this fear that often propels him to act even though he's terrified. He volunteered for the expedition for Gladys, the woman he loves, who doesn't love him - rather, she professes to love a certain ideal of man, one who will do great deeds in her name. The voyage to the Lost World was Malone's way of winning Gladys' heart... only now that he's here, he may very well never see her again. Add to that his growing attraction to Veronica, and you have one very muddled newspaper reporter.

Veronica (Jennifer O'Dell)
An innocent, she grew up in the Lost World. Her parents were part of an earlier expedition, also trapped on the Lost World. Most of the party died trying to get off the Plateau; Veronica's parents disappeared eleven years ago, while out collecting specimens. Since then, Veronica has been on her own.

She has survived by a mixture of wiles, friendships with local tribes, and luck - and maybe because of something else, watching over and protecting her. She is very physical, very able to protect herself and others. Growing up in the wild, without social constraints and customs, she has grown up free of the gender restrictions that characterised the times. She knows the dangers hidden in the Lost World; without her aid, the team would not survive. Betrayed by Marguerite in the pilot episode, she is no longer as quick to trust. She is disgusted by Roxton's tendency to kill first, ask questions later, but Malone and Summerlee manage to earn her confidence.

Professor Challenger (Peter McCauley)
Mid-forties. Adventurer, scholar, visionary. Married, he left his wife, Jessie, behind in England to lead the expedition to the plateau. The driving force behind the ill-fated expedition, he seeks glory above all else. It is his great failing as a human being that he doesn't only need to be right, he needs the world to acknowledge that he's right. Regarding their escape from the plateau, he has duelling impulses: on the one hand, he feels a sense of responsibility to the group to see them safely home: on the other hand, there's no point going home without proof positive of the existence of the prehistoric plateau.

On the plateau, there are no Great Minds for him to debate and abuse, as he had in London. Instead, he turns his formidable knowledge of science to a practical and pragmatic level. For example, developing an electrical generator to light - and protect - their base camp, with MacGyver-esque ingenuity. In England, pressmen such as Malone were beneath his notice, and even his fellow scientist, Summerlee, earned nothing but his contempt. Now, however, Challenger has lost civilisation - but he begins to find his humanity.

Lord John Roxton (William Snow)
Roxton's creed is simple: adventure is the only thing that makes life worth living. A man of few words, every situation for him is a challenge to be met and conquered. This brings him into conflict with the more peace-loving members of the group, notably Veronica. He is fearless, but his tough demeanour covers an emptiness that no amount of adventure can ever fill.

Roxton was the youngest son of a lord, and never expected to inherit his father's title. His older brother William, was the family favourite - gentle, a "good" boy, where young John was the rogue. Bookish, William was the kind of man who feared the world rather than embraced it. John coerced his brother into going on safari with him, to "be a man". On the safari, William and his brother were attacked by a great ape. As John ran for his gun, William was mauled by the creature. John fired into the ape's back, killing him - but the bullet went through the ape's body and killed his brother as well.

His father never recovered from William's death and died soon after. John inherited what should have been his brother's title - and a guilt that still gnaws at him and pushes him into adventures of even greater danger.