A troubling dream propels Thundarr, Ariel, and Ookla to journey to the past and warn their friends, Andy and Tarl Barlot of impending danger! A rival barbarian, Zoagarr has been recruited by a witch named Medusa, who desires Tarl as a consort. The promised reward is Andy as his mate. Zoagarr agrees. Arriving in modern-day Los Angeles ahead of the Christmas holidays, Thundarr and his crew reunite with the mutant Vampira, and her new friends from Angel Investigations. They are introduced to reformed vampire Angel. They team up to thwart Andy's kidnapping. But, Tarl is captured and taken to the future. He refuses Medusa's advances. She warns him to reconsider, or risk being turned to stone. A rescue team is mounted to rescue Tarl before it's too late. Within the Medusa's castle is a key to Thundarr's long-lost family, and his past? Will he find the brother he doesn't remember?