It was agreed the two would return by 6 o'clock. At 5 there was the faint sound of gunfire from somewhere in the hills. The scouts did not return at the appointed time. They did not return at all. Night came, and word spread among the townspeople of the disappearance of the two scouts. Anxiety increased as it became apparent they were under close surveillance by the enemy. Perhaps it was the intention of the nomads to wear them down with a winter-long siege of attack after attack, until they no longer had the ability or strength to fight. Hilliard and Johnson doubted this. The nomads were far less equipped for such a siege than Mayfield was. Maria continued to return to the radio shack in the evening to maintain the schedule with the network. She reported the plight of Mayfield to the other stations. From across the country came the fervent best wishes of those who heard her. Wishes were all they could offer. The scientists were particularly anguished because they considered the Maddox-Larsen group among the most likely to crack the barrier that kept them from conquest of the comet dust. "Our prayers are with you," the Pasadena group said. They sent a new report and Maria typed it and showed it to Professor Maddox that evening. He scanned it and put the pages in his coat pocket as he glanced out the window toward College Hill. "It seems like ages," he said. "I wonder if we'll ever get back up there." The next attack came well before dawn. Sheriff Johnson was among the first to be aware of it. The thunder of seemingly countless horses' hoofs was heard faintly out of the south and he put his glasses to his eyes. The nomads were a black patch against the snow. "How many horses have they got?" he exclaimed to the patrolman beside him. This was Ernest Parkin, one of his best officers. "I'd say there must be at least a hundred of them," said Parkin in awe. "They must have been gathering horses for weeks." "Feed," said Johnson, "for themselves and the animals--they may be rabble and savages, but they've had genius of leadership." Behind shelter, they waited for the blow. All orders had already been given. Only the general alarm was sounded now. It had been expected that the previous pattern of attack would be repeated. The defenders had been moved back from the barbed wire. They fired slowly and methodically with a splendidly efficient barrage as the nomads swung out of the night to blast with their grenades at the reconstructed fence. The way opened and they plunged in, the defenders closing behind and retreating to the other side of their barricades. Ken paced restlessly as he heard the shooting. "I'm going up on the roof," he told his father. "There can't be any objection to that." "I guess not. I'll call you when we need you."