Attracted by the report of the development of a new type of rocket fuel, the vicious dictator of Krangkor, the dark planet, descends on Earth to steal the formula from its creator, the benevolent Dr. Makin.
A group of Viking women build a ship and set off across the sea to locate their missing menfolk, only to fall into the clutches of the barbarian Grimolts who hold their men captive and worship the sea serpent which overturned their ship.