Dell and Emmelisa Planemaker have no sooner returned from their space mission to follow their dad's trail of light. than they are off on a new adventure!
They cannot contain their curiosity when another strange-looking man turns up on the old computer warning them not to go back to Hardwareland, where they'd trained to become astronauts,
A group of criminals attempt to steal money from Mrs. Planemaker, so Dell and Emmelisa set about learning how to stop them, and there's a great deal to learn! They return to Hardwareland to attend cyber crime courses, take scuba diving lessons and undergo submersible pilot training. When they've passed all the courses, the intrepid aquanauts are ready to begin their next mission: to fish out the cyber criminals.