A vicious band of nuclear terrorists is threatening America's atomic weapons research. Truck jockey Charlie Morrison volunteers for a last-ditch, suicide scheme to lure them into a trap, baited with a vital shipment of bomb-grade plutonium. Soon, Charlie's high-balling it down a remote desert road with a small army of lethally equipped bandits zeroing in on him. Charlie's secret weapon? "Big Thunder", a 65-foot, 18-wheeled war wagon of merciless high-tech destruction!