Climbing down the slope, not knowing whether to be glad or frightened, Vickers kept a close watch on the gleam of far-off metal. At times he lost sight of it when he dipped into the swales, but it was always there when he topped the rise again, so he knew that it was real.

Finally he was able to make out that what he saw were buildings — metallic buildings glinting in the sun, and now he saw that strange shapes came and went in the air above them and that there was a stir of life around them.

But it was not a city or a town. For one thing, it was too metallic. And for another, there were no roads leading into it.

As he came nearer, he made out more and more of the detail of the place and finally, when he was only a mile or two away, he stopped and looked at it and knew what it was.

It was not a city, but a factory, a giant, sprawling factory and to it came, continually, the strange flying things that probably were planes, but looked more like flying boxcars. The most of them came from the north and west and they came flying low, not too fast, dipping down to land in an area behind a screen of buildings that stood between him and the landing field.

And the creatures that moved about among the buildings were not men — or did not seem to be men, but something else, metallic things that flashed in the last rays of the sun.

All about the buildings, standing on great towers, were cup-shaped discs many feet across and all the faces of the discs were turned toward the sun and the faces of the discs glowed as if there were fires inside of them.

He walked slowly toward the buildings and as he came closer to them he realized for the first time the sheer vastness of them. They covered acre after acre and they towered for many stories high and the things that ran among them on their strange and many errands were not men, nor anything like men, but self-propelled machines.

Some of the machines he could identify, but most of them he couldn't. He saw a carrying machine rush past with a load of lumber clutched within its belly and a great crane lumbered past at thirty miles an hour with its steel jaws swinging. But there were others that looked like mechanistic nightmares and all of them went scurrying about, as if each of them were in a terrific hurry.

He found a street, or if not a street, an open space between two buildings, and went along it, keeping close to the side of one of the buildings, for it would have been what one's life was worth to walk down the center, where the machines might run one down.

He came to an opening in the building, from which a ramp led out to the street, and he cautiously climbed the ramp and looked inside. The interior was lighted, although he could not see where the light came from, and he looked down long avenues of machinery, busily at work. But there was no noise — that, he knew now, was the thing that bothered him. Here was a factory and there was no noise. The place was utterly silent except for the sound of metal on the earth as the self-propelled machines flashed along the Street.

He left the ramp and went down the street, hugging the building, and came out on the edge of the airfield where the aerial boxcars were landing and taking off.

He watched the machines land and disgorge their freight, great piles of shining, newly-sawed lumber, which was at once snatched up by the carrying machines and hustled off in all directions; great gouts of raw ore, more than likely iron, dumped into the maw of other carrying machines that looked, or so Vickers thought, like so many pelicans.

Once the boxcar had unloaded it took off again — took off without a single sound, as if a wind had seized and wafted it into the upper air.

The flying things came in endless streams, disgorging their endless round of cargo, which was taken care of almost immediately. Nothing was left piled up. By the time the machine had lifted into the air, the cargo it had carried had been rushed off somewhere.

Like men, thought Vickers — those machines act just like men. Their operation was not automatic, for to have been automatic each operation must have been performed at a certain place and at a regular time — and each ship did not land in exactly the same place, nor was the time of their arrival spaced regularly. But each time that a ship landed the appropriate carrying machine would be on hand to take charge of the cargo.

Like intelligent beings, Vickers thought, and even as he thought of it, he knew that that was exactly what they were.

Here, he knew, were robots, each one designed to take care of its own particular task. Not the man-like robots of one's imagination, but practical machines with intelligence and purpose.

The sun had set and as he stood at the corner of the building he looked up at the towers which had faced the sun. The discs atop the towers, he saw, were slowly turning back toward east, so that when the sun came up next morning they would be facing it.

Solar power, thought Vickers — and where else had he heard of solar power? Why, in the mutant houses! The dapper little salesman had explained to him and Ann how, when you had solar plant, you could dispense with public utilities.

And here again was solar power. Here, too, were frictionless machines that ran without the faintest noise. Like the Forever car that would not wear out, but would last through many generations.

The machines paid no attention to him. It was as if they did not see him, did not suspect he was there. Not a single one of them faltered as they rushed past him, not a single one had moved out of its way to give him a wider berth. Nor had any made a threatening motion toward him.

With the going of the sun, the area was lighted, but once again he could not determine the source of the light. The fall of night did not halt the work. The flying boxcars, great, angular, box-like contraptions, still came flying in, unloaded and flew off again. The machines kept up their scurrying. The long lines of machines within the buildings kept up their soundless labor.

The flying boxcars, he wondered, were they robots, too? And the answer seemed to be that they probably were.

He wandered about, hugging the building to keep out of the way.

He found a mighty loading platform, where the boxes were piled high, carried there by machines, loaded into the flying boxcars by machines, steadily going out to their destination, wherever it might be. He edged his way onto the platform and looked at some of the boxes closely, trying to determine what it was they held, but the only designations on them were stenciled code letters and numerals. He thought of prying some of them open, but he had no tools to do it, and he was just a bit afraid to do it, for while the machines continued to pay no attention to him, they might pay disastrous attention if he interfered.

Hours later he came out on the other side of the sprawling factory area and walked away from it, then turned back and looked at it and saw it glowing with its strange light and sensed the bustle of it.

He looked at the factory and wondered what was made there and thought he could guess. Probably razor blades and lighters and maybe light bulbs and perhaps the houses and the Forever cars. Maybe all of them.

For this, he felt certain, was the factory, or at least one of the factories, that Crawford and North American Research had been looking for and had failed to find.

No wonder, he thought, that they had failed to find it.