The station was raised on a tripod to a height of one thousand feet, and the Army had the whole structure properly reinforced and shielded. Then the equipment for observation, the TV monitoring screens and the electron telescopes, was set up and the generals moved in. The old physicist had by this time taken a loyalty oath and he was allowed to remain in the observation dome for the event since, after all, he worked there.

At zero hour minus sixty seconds the senior general carefully pressed a small red button and unwittingly echoed the words of a forgotten subordinate. “We’ll blast the son of a bitch sky high,” he said. Flashbulbs popped. A counter began ticking off the seconds, loudly, efficiently. All eyes were on the large TV screen, which showed the huge circle of white neo-adamant four hundred miles away. The TV picture was being beamed from a satellite eighty miles above the location of the brick; they would be able to see the actual blast before the camera was destroyed. The physicist busied himself with his own instruments, making readings of the sun’s position. The seconds ticked off.

At the sixtieth tick the counter became silent. There was no sound in the little observation tower. The white circle on the screen was unchanged. Then, suddenly, the screen erupted. In a burst of flame and steam the neo-adamant circle began to crumble. Flames shot up everywhere. Mountains seen at the edge of the screen began to sizzle and ooze out of shape. It was at this moment that the states of Virginia, West Virginia and Ohio were obliterated. Then, abruptly, the picture changed. A specially controlled monitoring camera had picked up a flash of gold. The brick. It appeared to be flying through the air.

“By God,” said the senior general. “We did it!”

At this moment the screen went black. There was a roar, a rumble, starting from what seemed to be the very bowels of the Earth, building to a dynamic, deep-buried scream, a screeching of wrenched rock and of the tearing of the Earth’s crust; and then a sickening lurch, a nauseous dip and lunge of sideward motion, a sense of acceleration; and then a howling sound, the howling of a sudden, tremendous wind. The generals were all thrown to the floor, trembling.

Somehow the physicist had remained standing, holding the sides of the table on which his instruments were mounted. His old hands were white with the strain and were trembling, but his face was ecstatic. “Amazing!” he said. “Amazing!” His eyes were shining.

“What happened?” one of the generals said weakly, from the floor.

“Propkofski! Propkofski was right!” said the other, his voice jubilant, shaking with emotion. “That was the intersection of the mass-influx lines. The brick, the gold brick, was the keystone, the hub! It held the Earth up.”