The defense forces of the United States have been crushed by the powerful war machine of Emperor Rudolph, Warlord of the World... From the Atlantic to the Mississippi the brutal conqueror is subjecting millions to his merciless, bloody reign of terror-and his ruthless gray-clad hordes are steadily sweeping westward, leaving a vast path of death and destruction in their wake... Faced with the surrender of America's army, only Jimmy Christopher-known to the Intelligence Service as Operator 5-and a pitiful handful of desperate men stand between the Mad Emperor and his bloody conquest of the nation...