When the star of The Grateful Fred receives threatening letters, he calls on Melvin, the superhero in charge of Los Angeles, and his assistant, Candace, to stop the criminal and his henchmen before they destroy Fred's reputation.

After graduating from the superhero academy, Melvin Beederman heads for Los Angeles, where he unexpectedly teams up with Candace Brinkwater, school play actress, to nab the evil McNasty Brothers.

With her uncle's cape, training from Grandpa Joe, a retired sheriff, and her drooling dog Raymond as her sidekick, fourth-grader Jo Schmo becomes a superhero, catching bank robbers and foiling Dr. Dastardly's plan to take over San Francisco using reanimated dinosaurs.

Fourth-grade superhero Jo Schmo and her sidekick Raymond face Dr. Dastardly and Numbskull, who break out of jail and join forces with Pinkbeard's band of time-traveling pirates in an evil revenge plot.