When the three members of the Bad Guy Brotherhood buy a time machine to keep the younger Melvin from gaining his superhero powers, Melvin and his sidekick Candace, disguised as pirates, travel back in time to stop them.

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.

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.