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.

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

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.

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

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.

On a bridge spanning a deep gorge, a fierce battle unfolds with Drakul's raiders. Marguerite and Veronica watch as Summerlee is hit. Tribune, betrayed by Drakul, hurls a bomb that destroys the bridge...throwing the men into the river far below. Veronica clings to the hope that her friends have survived and searches for them with Marguerite. Once reunited, they discover that Tribune has saved Roxton's life and demands a favor in return. Since they need a boat to return home, they follow Tribune to a run-down fishing village - where he disappears. A beautiful prostitute named Raina informs them that Nemak has enslaved the town. When our gang clashes with Nemak and his goons, they are thrown into jail.

A riderless horse approaches our explorers, as if on a mission. When Roxton saddles up, the horse carries him to a mountain tribe, who welcome him as their king. Roxton tries to decline, but when the royal advisor, Balar, tells him that if he's an imposter; he shall die, Roxton reconsiders. Using the horse, Roxton tries to warn his friends. Balar has the horse followed and they are captured. One of the customs of the tribe is to sacrifice a virgin to appease a monstrous dragon, but Roxton saves the young woman and steps right into Balar's trap. The only way to stop the dragon now is for the rightful king to hunt it down and kill it.

When Marguerite starts being nice to everyone, they wonder what she's up to. Even when pushed to find out why she's acting this way, she maintains her uncharacteristic serenity. In the jungle, Roxton and Veronica are attacked by a dinosaur that after giving them a huge scare, starts to move very clumsily, giving them a chance to escape. We learn that an alien invader, who could not control the dinosaur's huge body, occupied it. We also learn that Marguerite's body has been possessed when she drops her spoon into a vat of boiling water and plunges her arm in to retrieve it - with no ill effect. We discover that the Alien Invaders are skeletons that our heroes have to fight.

As mysterious drums sound through the jungle, Roxton is stalked and seduced by a beautiful woman, Danielle, who tells a harrowing tale of Trogs attacking and taking over her village. Seeking refuge at the Treehouse, she manages to charm the men but arouses the women's suspicions. Their mistrust is justified when Danielle makes a voodoo doll in Roxton's image and lures him back to her village, where it turns out, she is the one who controls the Trogs and an army of zombies. When the others discover that Roxton has been enslaved, they quickly devise a plan to infiltrate the village and rescue him.

When Malone is slashed by a beast in the jungle, he shoots wildly. While looking for the animal, he and Veronica come across Danu, her childhood sweetheart, wounded, and warning them of the danger from this beast. Later that night, the team is disturbed by a howling animal, and discovers Danu gone and Malone feverish. Marguerite stays to nurse Malone, the others search for Danu, hoping to learn more about Malone's condition. Veronica leads them to his village, where only a witchdoctor and a few warriors armed with silver-tipped weapons, remain. The witchdoctor tells them that Danu has become a werewolf and must be killed by silver or fire, there is no cure. She gives Veronica a potion to delay the onset of Malone's transformation, then sends Challenger and Roxton to the Valley of Shadows where the werewolves live. Danu, wanting to transform Veronica to a werewolf like him, drives her towards the Valley of Shadows.

Hoping to end starvation, Challenger becomes the first human subject to test his new experimental substitute for food. But his nutritional beverage is not as successful for him as it was for his lab mice, and he quickly becomes obsessed with discovering the reason why. Then obsession leads to madness as Challenger is confronted by two opposing hallucinations. The first is a vision of himself as a young, driven scientist. The second is his beloved wife, Jessie, as he left her in London three years earlier. Unconscious and near death, Challenger is finally discovered by his friends. But will their limited medical knowledge be enough to reverse the ravages of his experiment, without placing him in even greater peril?

Two days before Challenger's latest attempt to leave the Plateau by balloon, Veronica and Finn encounter a strange phenomenon and are briefly transported into the post-apocalyptic future of New Amazonia. Soon after, Roxton finds himself being chased by 17th-century Conquistadors while Marguerite is captured by Druids determined to sacrifice her in order to avert a mysterious storm which is fast approaching.

As different planes of reality continue to collide, Veronica at last realizes the time has come for her to fulfill her destiny as Protector and wield her mother's pendant-the Trion. But even as she prepares to sacrifice her life to save her friends, she does not know if she's made the right decision-for once the power of the Trion is unleashed, will it save the Plateau, or destroy it… ?