little stream that had its beginning
at the lake. They moved on across the mountains and over the green
foothills until they came to a broad, rolling plain.

"I wonder if this planet _is_ inhabited," Arcot mused. "None of this
land seems to be cultivated."

Morey had been scanning the horizon with a pair of powerful binoculars.
"No, the land isn't cultivated, but take a look over there--see that
range of little hills over to the right? Take a look." He handed the
binoculars to Arcot.

Arcot looked long and quietly. At last he lowered the binoculars and
handed them to Wade, who sat next to him.

"It looks like the ruins of a city," Arcot said. "Not the ruins that a
storm would make, but the ruins that high explosives would make. I'd say
there had been a war and the people who once lived here had been driven
off."

"So would I," rejoined Morey. "I wonder if we could find the
conquerors?"

"Maybe--unless it was mutual annihilation!"

They rose a bit higher and raised their speed to a thousand miles an
hour. On and on they flew, high above the gently rolling plain, mile
after mile. The little brooklet became a great river, and the river kept
growing more and more. Ahead of them was a range of hills, and they
wondered how the river could thread its way among them. They found that
it went through a broad pass that twisted tortuously between high
mountains.

A few miles farther on, they came to a great natural basin in the pass,
a wide, level bowl. And in almost the exact center, they saw a looming
mass of buildings--a great city!

"Look!" cried Morey. "I told you it was inhabited!"

Arcot winced. "Yes, but if you shout in my ear like that again, you'll
have to write things out for me for ever after." He was just as excited
as Morey, nevertheless.

The great mass of the city was shaped like a titanic cone that stood
half mile high and was fully a mile and a half in radius. But the
remarkable thing about it was the perfect uniformity with which the
buildings and every structure seemed to conform to this plan. It seemed
as though an invisible, but very tangible line had been drawn in the
air.

It was as though a sign had been posted: "Here there shall be buildings.
Beyond this line, no structure shall extend, nor any vehicle go!"

The air directly above the city was practically packed with slim, long,
needle-like ships of every size--from tiny private ships less than
fifteen feet long to giant freighters of six