Forced to relinquish the Casket of Chronos, which allows time travel into the past to alter the future, to the Exponoids the crew pursue them to 1950s America, where technology is banned, thus allowing the Exponoids world domination without any challenge. A dying dissident directs them to Harmony De Gaultier, whose speak-easy is frequented by underground scientists, including Einstein Dave, who helps them redress the balance and regain their ship.
—don @ minifie-1