He did not pause in his rocket salvos, but in three minutes and eight seconds his first salvo of one-ton atom bombs would reach the Marseilles screen. If he had calculated correctly, the Marseilles screen would be open for an instant just as the atom bombs reached it. He didn't think Forgacs could resist the temptation to blast Philadelphia with his Marseilles batteries. Presently a thousand red lights winked up from the screen at Marseilles. But Forgacs overlooked the atom bombs. They were slower than the rockets, and there was no way to tell, from the Map, which was which. Jeffrey shot a look at the chronometer, and Hoshawk saw the atom bombs go through. A few seconds later the glow in Marseilles began to redden, and Hoshawk exulted. The atom bombs had done their work. The Marseilles screen was weakening. Jeffrey played the keys with fantastic speed. The war would soon be over. Thousands of little red lights began streaking toward Marseilles. At first they exploded in air as they hit the screen, but as the explosive force of the DTN began to drain the screen, those behind began to pour through. But there was a flash from Philadelphia, and a shock went through Hoshawk. Something was wrong there. Jeffrey hadn't intended that. Forgacs had used atom bombs and had broken through when the screen was down. Jeffrey's fingers snatched at the oxygen valve. He tore it off and threw it on the floor. He still held one important advantage. He was ahead of Forgacs by forty seconds. Philadelphia went out and the golden defensive screen began to fade, but Jeffrey, tensely erect, stayed on the attack. Hundreds of green lights began to rise around Marseilles--great submarines, controlled by electronics and carrying tanks and guns and explosives. The green lights converged on Marseilles. They got through the screen. Now was the big gamble. Jeffrey guessed that Forgacs would operate from an underground chamber near Marseilles itself. It wasn't a logical thing to do, and so Forgacs would do it, believing that Jeffrey would pass Marseilles and go inland to find the Chamber. Jeffrey let him believe that. He sent eight thousand giant electron-controlled bombers through the Marseilles gap and straight for Berlin. The green lights started winking on the coast of France, showing the submarines were unloading amphibious tanks. Jeffrey started them out across France at high speed. Near Paris they met heavy resistance from Forgacs' tank-killers. But now Jeffrey had more trouble. Forgacs had slipped a salvo of atom bombs into the Labrador power station, and the entire north quadrant of Jeffrey's screen was down. And just at that instant, the automatic breaker failed and a tube burned out in the Montevideo power station, and the southern half of South America was exposed. Green lights began to wink up at the open spaces. * * * * *