The Mighty Morphin Power Rangers are doing battle with the other-worldly villainess Divatox (Hillary Shepherd). She is the wife of an evil lord named Maligore who is imprisoned in an energy vacuum inside one of Earth's volcanoes. Freeing him would mean doom for the universe. The five Rangers disguise themselves as ordinary teenagers, but their secret is discovered by ten-year-old Justin (Blake Foster), and he is allowed to don a power suit and become one of them. Zordon (Winston Richard), the Power Rangers' boss, gives his crew extra powers to thwart Divatox, who with her pirates has captured a submarine. The showdown between the forces of universal good and evil includes plenty of karate and kick-boxing around a seething cauldron of lava.