Thundarr, Ookla, and Ariel are in pursuit of a mummy-like Janus after he and a race of hawk mutants attack villages and the train route of Tye (the former swamp urchin from "Harvest of Doom"). The group is in for a surprise when it turns out Janus is actually Gemini (the two-faced wizard from "Secret of the Black Pearl") in disguise seeking revenge on Thundarr. Tye, from "Harvest of Doom", returns as a train driving "businesswoman".

A spaceship containing an alien vampire lands on Earth. The alien captures Princess Ariel and all the villagers in the ruins of Lakeside Amusement Park hidden under the snow and ice of the Rockies as a source of its food.

Thundarr, Princess Ariel, and Ookla are caught up in a battle between the wizards Sholow and contestants Basim, Skorpos and Chom who seek the Helmet of Power. Thundarr ends up having to side with the wizard Sholow when he threatens a group of villagers.

Thundarr, Princess Ariel, and Ookla come to the aid of a race of amphibious Amazons led by the deposed Queen Diona who has been usurped by Stryia, an evil half-human, half-shark wizard-queen who plans to conquer both the land and seas with her shark legion army.

Thundarr, Princess Ariel, and Ookla come to the aid of the Mok Chieftain Oblach against Captain Kordon, Queen of the River Pirates, who is after the Mok's hidden treasure and intends to use the "fire lances of the ancients" to get it.

Zevon is the leader of the Brotherhood of Night, a tribe of werewolves that can add anyone to their ranks by touching them and is also targeting the evil wizard Infernus hoping to make the pack completely invincible.

Simius and his fellow Man Apes assemble salvaged parts of a movie studio's giant robotic gorilla in a plot to terrorize the local villagers.

Thundarr's friend Thorac is accused of stealing a village's fuel and is about to receive a death sentence (by being boiled alive over a geyser) when the barbarian rescues him. Thorac is granted a reprieve when Thundarr and the group investigate the crime, eventually learning the town's sheriff Korb is in league with the evil wizard Artemus. Artemus had stolen the fuel to power his Death Ship and gain the approval of the Council of Wizards.

The evil wizard Crom threatens a tribe of humans at the Alamo. They can protect themselves by using a sophisticated Guardian machine that utilizes flying robot drones that can disable the wizard's laser tanks. However, it blows a circuit and cannot be replaced as circuits are no longer produced. Their only hope is to infiltrate Crom's lair in order to use his moon dial, which sends them to Old Earth. In the 20th century, Thundarr, Ookla and Ariel are aided by a little girl named Samantha, who helps them obtain a fresh circuit. The trio return to New Earth and prepare for battle with Crom, but are glad they had a chance to see the preapocalyptic world.

Thundarr, Princess Ariel, and Ookla battle the evil wizard Vashtarr when he steals the Crystal of Prophecy that can give the details of his downfall. When it shatters in his efforts to retrieve it, the prophecy is foretold as they learn three women will unite to defeat him. One is Maya, an element-shifter buried in the ruins of the old city of Endorr. Another is Cinda, a hermitic barbarian living in the Canyon of Death whose staff grants her great strength. The last is Valerie Storm, a fashion model from Old Earth who is abducted and taken prisoner by Vashtarr himself.

Thundarr, Princess Ariel, and Ookla encounter a train carrying Death Flowers (whose pollen can hypnotise both humans and Moks) being transported by the Carocs (a race of crocodile people) to a wizard.

The evil wizard Kublai seeks the Golden Scepter of the Yantzee (the only item which can strip him of his magic) and terrorizes the villagers of San Francisco's Chinatown in the process. When Thundarr thwarts his initial attempts, the wizard recruits another barbarian named Zogar to engage him in battle while Kublai tries again to find the scepter.