Roxton is looking for the materials for a crossbow to bag a T-Rex, but when one actually interupts him in his labors, he runs in the direction opposite his fellow travelers to keep them safe. He winds up falling into a hole that suddenly opens up. When the rest of the group search for him, they also fall into the hole, which turns out to be a whirlpool. It sucks them all under the water, and they emerge in a lake. They quickly find out that in this part of the plateau, the dominant species are lizard-like men, descendents of dinosaurs, and the humans are subservient to them. There is an ancient Roman structure to this civilization, including gladiator-type battles. While Marguerite and Veronica are forced to change into silky gowns for the entertainment of Tribune, the lizard-people's leader, Roxton is chosen to fight another human prisoner. The slaves and travelers rebel, and overthrow the lizard-men's intolerable rule, but not without loss ~ Roxton's opponent's sister ~ a rebel leade

Veronica and Summerlee are out gathering fruit and floral specimens when they are attacked by a huge bee, one the size of a man. Summerlee is stung, and it leaves him near death. The only cure is the nectar in the heart of the hive. Veronica, Malone and Roxton travel to the hive, leaving Challenger and Marguerite behind at the treehouse to care for Summerlee. Summerlee is delirious with fever, and imagines Marguerite is his long-dead wife. She plays along, to sooth him. In the meantime, Veronica, Malone and Roxton do make it to the hive, work their way deep into it, gather nectar, and head back quickly to the treehouse, just in time to save Summerlee's life.

Challenger, Malone and Veronica are searching for sulfur, in order to make more gunpowder, when they walk into a burial ground. They are attacked by warriors in black and white paint who capture Challenger. That night the group sneaks into the warriors' village...to find Challenger sitting quietly and drinking tea with a beautiful blonde woman named Cassandra. She and her husband had been part of an early expedition, also stranded and found by the warriors tribe twelve years ago; they were soon made king and queen there. She tells our group that going onto the burial grounds was considered taboo, and for this Challenger would have to remain captive for life. The only way they can save him is by going to the Cave of Fear and retrieving her husband's bones for burial. They set off, but soon discover why the cave is avoided ~ it's walls are covered in a hallucinogenic fungus, wtih a really nasty additional effect. It drives those affected to suicide - which Cassandra apparently knew when

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.

While out in the jungle, Malone is hit in the neck with a poisoned dart and dies. A shaman, Lento, heals him and Malone is brought back to life, but Lento has been driven mad. He is sentenced to die by his village, but Malone rescues him. Summerlee is kept captive and will die unless Malone, Roxton and Challenger can bring Lento back. Lento leads them a merry chase, having booby-trapped the jungle, but the men do eventually catch up to him , and he is killed. In the meantime, back at the treehouse, Veronica and Marguerite have had a huge fight, and wind up down an old well, with a hungry dinosaur waiting for them above and snakes, water and each other, in the hole!

Tracking a stream, Challenger, Veronica, Malone and Marguerite run into a group of Vantu headhunters. There is nowhere to run or hide, except in what looks like an overgrown cave opening. They dash into it only to discover it is man-made, an old, crumbling mine shaft. There's a loud rumbling that leads to a cave-in. Veronica escapes, but the others are trapped inside. Near death from suffocation, they are saved by Garza, part of a group banished to the mine by a plague-like disease, and led by a blind little boy known as The Oracle. The boy decrees our group must remain underground forever, and is unswayed even by Challenger's discovery that the tremors are caused by a sleeping volcano waking up around them. On the outside, Veronica manages to get Roxton and Summerlee from the treehouse, but they meet up with the Vantu again, who are not easily persuaded to let them rescue the others from their mountain prison.

Roxton saves Tayra of the Tinta people from a Hikari warrior who is chasing her. The two men fight and the Hikari man is killed. Roxton discovers that the Tintas live in fear of the fierce Hikari, and pay them a tribute to ensure the Hikari leave them in peace and protect them from other dangers. The Tinta are very peaceful, a fishing and gathering tribe, and do not know how to fight, but are determined to stop the tribute practice, but freedom may come at a high price. Roxton and Veronica teach them some fundamentals of hand to hand, help set up some traps to slow the Hikari down and help the Tinta organize in defense of their village, which the Hikari are due to strike, since there was no tribute paid. Challenger reluctantly helps, since he is not sure whether the Tinta are going to survive the fight ~ he does rouse them the night before with some inspring words from Shakespeare. The day of battle dawns and at the end, the fight is won, but the cost is great in Tinta lives, including

When he finds a powerful crystal, Professor George Challenger gains the powers of a God, putting himself and the other explorers in great danger.

Marguerite is the future Queen of Camelot as far as a boy King is concerned, but the explorers and Marguerite, as well as the King's crafty advisor don't agree.

Challenger, Roxton, and Veronica come upon an old friend of Challengers, who resembles the sadistic ""creator"" Dr. Moreau. Elsewhere, Summerlee, Malone, and Marguerite meet an elderly woman who has a radio headset.

Though the explorers find a gateway that can transport them back home, following them are enemies: one who doesn't want them to return, and one who does but wants them to bring a deadly virus with them.

Veronica thinks she has found her father, but instead she has found an imitator, with deceit in mind.

Deep in the jungle, Marguerite, Challenger and Malone come upon a half-buried, mummified corpse. They are shocked when it shows signs of life. They learn the would-be corpse, Ramses, is Egyptian royalty. He weaves a tale about a wonderful kingdom with untold riches and how he was to become king. He then enlists our heroes in a plan to reclaim the throne he says has been stolen from him by his sister, Nefertiti. After agreeing to help, the three discover there is more to the dispute than Ramses is revealing. He rules with an iron fist, enslaving his former enemies. He blinds his sister, and leave her to die. Marguerite, Challenger and Malone help her escape. The adventurers decide they must defeat Ramses by convincing the true heir, Nefertiti, to accept the responsibility of rule, and helping her regain control. Meanwhile, Summerlee is relentlessly pursued by a T-Rex after she mistakenly believes him responsible for the death of her babies. Roxton and Veronica must help their friend or

After days of searching the mountains for a pass off the plateau, Roxton and Marguerite are camped for the night when they are taken by surprise by Norse warriors. Roxton is run through with a sword by the leader, Ursula. As he sinks to his knees, Marguerite is hauled off by the raiders. Near death, Roxton is visited by a mystical young boy named Osric, who offers a deal. Osric will restore Roxton's life so he can save Marguerite. However, there is a catch. Roxton agrees to the deal and Marguerite is saved. It turns out that Osric is the soul of evil who has been imprisoned on the Lost World. He reappears and gleefully informs Roxton that he must murder Bergen, an old man with a long-standing hold over the boys' manipulative intentions. Roxton refuses to kill the old man, but Osric has many deadly ways to get what he wants. Meanwhile, Malone and Veronica must defend their Treehouse from a band of cutthroats who will stop at nothing to take it from them.

When the explorers rescue a fortune teller from her runaway horses, she tells them their future, which begins to come true little by little, but in a different way than they expect.

Teenage Gideon and his mentor Davos are on a mission to fulfill the boy's destiny of leading his tribe of Moya out of the bondage of the evil Goths. Roxton and Marguerite come upon them, just as Davos is fatally wounded in a Goth attack. Before he dies, Davos charges Roxton with ensuring Gideon and the ""Star of Hope"" quarterstaff he carries, reach their destination. What they discover is that Gideon has been taken from his parents as a child, raised by monks, and chosen to lead his people from the isolated caves where they have hidden for a generation.

The explorers are caught in the middle of a war between Tribue, with gunpowder in toe, and Drakul and his barbaric raiders. One of them will be lost, possibly forever, when this battle reaches its cliffhanger!

An unsettling dream and a ghostly encounter convince Veronica that Malone is trapped in the spirit realm and needs her help to escape. At the same time, Assai and Challenger investigate a mysterious symbol burned into a field of grass, which Assai identifies as the mark of Saros, a bloodthirsty warlord who was overthrown by the Zanga and died swearing to return from the grave to wreak vengeance on the living. Back at the treehouse, Marguerite and Veronica use a Ouija board to contact Malone, which results in a frightening display of poltergeist-like activity, and a brief, but terrifying manifestation of Saros. Assai is convinced that any new attempt to rescue Malone from the spirit realm threatens to release Saros instead.

When a powerful witch named Dame Alice feels threatened by Challenger's science, she calls upon her two beautiful acolytes to help undo his power. In order to earn full witchhood, the two must lure Challenger's ""guards"" - Roxton and Malone - to the witch's castle while she goes head to head with the ""wizard"" - Challenger - herself.

While the two young witches distract Roxton and Malone, Dame Alice visits the Treehouse for a visit. In spite of Marguerite's protests and warnings, Challenger is intrigued by the witch's power and too easily lowers his guard. When Dame Alice sabotages Challenger's newest invention and almost kills him, it is only Marguerite's quick thinking that saves the scientist from his own folly. But in the end it is not Challenger's life that is in danger, but the lives of Roxton and Malone….

When Keeran Raiders attack, a deadly poison dart forces Malone to relive a long-suppressed memory-his baptism of fire as a battlefield correspondent in World War I. Caught up in this nightmarish hallucination, Malone is once again an untried reporter cut off from Allied lines when an enemy advance pushes deep into No Man's Land. When the three battle-weary British soldiers who've been assigned to escort him are picked off by enemy action, the young reporter who's never fired a gun must take up arms to save his own life and the life of a wounded sergeant.