The President hardly watched them. His screen with its principal power-plant in Philadelphia would stop the rockets, up to a total of some seventy-five octillion macro-ergs.
On the off chance that Forgacs would forget to close his screen after his rockets had passed it, Jeffrey fired a salvo from the Bahamas.
Forgacs answered with three salvos from Brest, and Jeffrey gave him back ten from Long Island, then Hoshawk frowned as he saw the President rub his stomach. Hoshawk had always opposed that abominable atavistic confection called ice cream.
It was a game of incredibly swift calculation and rapier thrusts from strong point to strong point in the effort to break through the screen. Once the screen should be broken, anything might happen.
Jeffrey could see when his own screen was up, but their science had devised no way to detect the enemy's screen except by firing into it. Jeffrey pressed a pedal with his left foot, and a thin golden line flashed on in a flattened arc from Greenland down through the Atlantic and curved around the Falkland Islands.
Jeffrey's screen was up. The Biscay salvos began to wink out against it. Jeffrey's hands began to flash. Red lights winking up along the coast of Europe and from North Africa showed that Forgacs was opening up.
Jeffrey cut in the oxygen for a second and flicked it off, then his left foot slashed at the pedal as he cut his screen to let his own rockets through and then threw it on again to stop the enemy.
Forgacs was beginning a drive on Philadelphia, the site of the power plant. Jeffrey was watching for an opening to Marseilles, vulnerable for the same reason.
Jeffrey kept firing rockets, but his mutant mind would be racing ahead, calculating with infinite precision the times of discharge and times of arrival.