In the company of the ghostly pirate Ivanka, the elusive Doctor Marbles is back, and this time he’s discovered a powerful cybermineral he can use to help Motherboard. Located deep inside a volcano on the cybersite Corsario, this “Magmalux” is strong enough to override the virus Hacker inflicted on the beloved Cyberspace ruler. Unfortunately, Hacker is on to Marbles and traps him on Skull Island so he can retrieve the Magmalux for his own evil purpose. Enter the CyberSquad: Digit tracks Hacker while the kids solve another problem: how to rescue Marbles! Hacker has destroyed the bridge to Skull Island, and the water surrounding it is infested with electric eels. Can they build a new bridge—with just an old sign to work with—and get to the volcano in time to stop Hacker?