A Joe transport plane is caught in a storm, forcing the pilot to ditch his cargo, a valuable Mauler tank, over the desert. Dusty and Footloose volunteer to stay with the tank until it can be retrieved. They inadvertently parachute onto a Cobra proving ground and discover the evil organization's latest innovation: a metal alloy that's impervious to any conventional weapon! With tanks and planes constructed of this alloy, Cobra could attack the Joe team – or anyone else – without fear. With a battalion of Cobras hot on their heels, can Dusty and Footloose survive the track across the hostile desert to warn the Joes?