"'People couldn't possibly live in hydrogen instead of oxygen'," Arcot quoted, grinning. "That's what they told me when I made my little announcement at the meeting on the Black Star situation. The only trouble was--they did. That suggestion of yours meets the same fate, Morey!"

"All right, you win," agreed Morey. "Now let's see if we can find the other nations on this world more friendly."

Arcot looked at the sun. "We're now well north of the equator. We'll go up where the air is thin, put on some speed, and go into the south temperate zone. We'll see if we can't find some people there who are more peaceably inclined."

Arcot cut off the invisibility tubes. Instantly, all the enemy ships in the neighborhood turned and darted toward them at top speed. But the shining _Ancient Mariner_ darted into the deep blue vault of the sky, and a moment later was lost to their view.

"They had a lot of courage," said Arcot, looking down at the city as it sank out of sight. "It doesn't take one-quarter as much courage to fight a known enemy, no matter how deadly, as it does to fight an unknown enemy force--something that can tear down mountains and throw their forts into the air like toys."

"Oh, they had courage, all right," Morey conceded, "but I wish they hadn't been quite so anxious to display it!"

They were high above the ground now, accelerating with a force of one gravity. Arcot cut the acceleration down until there was just enough to overcome the air resistance, which, at the height they were flying, was very low. The sky was black above them, and the stars were showing around the blazing sun. They were unfamiliar stars in unfamiliar constellations--the stars of another universe.

In a very short time, the ship was dropping rapidly downward again, the horizontal power off. The air resistance slowed them rapidly. They drifted high over the south temperate zone. Below them stretched the seemingly endless expanse of a great blue-green ocean.

"They don't lack for water, do they?" Wade commented.

"We could pretty well figure on large oceans," Arcot said. "The land is green, and there are plenty of clouds."

Far ahead, a low ma.s.s of solid land appeared above the blue of the horizon. It soon became obvious that it was not a continent they were approaching, but a large island, stretching hundreds of miles north and south.

Arcot dropped the ship lower; the mountainous terrain had become so broken that it would be impossible to detect a city from thirty miles up.

The green defiles of the great mountains not only provided good camouflage, but kept any great number of ships from attacking the sides, where the ray stations were. The cities were certainly located with an eye for war! Arcot wondered what sort of conflict had lasted so long that cities were designed for perpetual war. Had they never had peace?

"Look!" Fuller called. "There's another city!" Below them, situated in a little natural bowl in the mountains, was another of the cone cities.

Wade and Fuller manned the ray projectors again; Arcot dropped the ship toward the city, one hand on the _reverse_ switch in case the inhabitants tried to use the magnetic beam again.

At last, they had come quite low. There were no ships in the air, and no people in sight.

Suddenly, the outside microphone picked up a low, humming sound. A long, cigar-shaped object was heading toward the ship at high speed. It had been painted a dark, mottled green, and was nearly invisible against background of foliage beneath the ship.

"Wade! Catch that on the ray!" Arcot commanded sharply, moving the ship to one side at the same time. Instantly, the guided missile turned and kept coming toward them.

Wade triggered the molecular beam, and the missile was suddenly dashing toward the ground with terrific speed. There was a terrific flash of flame and a shock wave of concussion. A great hole gaped in the ground.

"They sure know their chemistry," remarked Wade, looking down at the great hole the explosion had torn in the ground. "That wasn't atomic, but on the other hand, it wasn't dynamite or TNT, either! I'd like to know what they use!"

"Personally," said Arcot angrily, "I think that was more or less a gentle hint to move on!" He didn't like the way they were being received; he had wanted to meet these people. Of course, the other planet might be inhabited, but if it wasn't--

"I wonder--" said Morey thoughtfully. "Arcot, those people were obviously warned against our attack--probably by that other city. Now, we've come nearly halfway around this world; certainly we couldn't have gone much farther away and still be on the planet. And we find this city in league with the other! Since this league goes halfway around the world, and they expected us to do the same, isn't it fair to a.s.sume, just on the basis of geographical location, that all this world is in one league?"

"Hmmm--an interplanetary war," mused Arcot. "That would certainly prove that one of the other planets is inhabited. The question is--which one?"

"The most probable one is the next inner planet, Aphrodite," replied Morey.

Arcot fired the ship into the sky. "If your conclusions are correct--and I think they are--I see no reason to stay on this planet.

Let's go see if their neighbors are less aggressive!"

With that, he shot the ship straight up, rotating the axis until it was pointing straight away from the planet. He increased the acceleration until, as they left the outer fringes of the atmosphere, the ship was. .h.i.tting a full four gravities.

"I'm going to shorten things up and use the s.p.a.ce control," Arcot said.

"The gravitational field of the sun will drain a lot of our energy out, but so what? Lead is cheap, and before we're through, we'll have plenty or I'll know the reason why!"

Dr. Richard Arcot was angry--boiling all the way through!

XV

There was the familiar tension in the air as the s.p.a.ce field built up and they were hurled suddenly forward; the star-like dot of the planet suddenly expanded as they rushed forward at a speed far greater than that of light. In a moment, it had grown to a disc; Arcot stopped the s.p.a.ce control. Again they were moving forward on molecular drive.

Very shortly, Arcot began to decelerate. Within ten minutes, they were beginning to feel the outermost wisps of the cloud-laden atmosphere. The heat of the blazing sun was intense; the surface of the planet was, no doubt, a far warmer place than Earthmen would find comfortable. They would have been far better suited to remain on the other planet, but they very evidently were not wanted!

They dropped down through the atmosphere, sinking for miles as the ship slowed to the r.e.t.a.r.ding influence of the air and the molecular power.

Down they went, through mile after mile of heavy cloud layer, unable to see the ground beneath them.

Then, suddenly, the thick, all-enveloping mists that held them were gone. They were flying smoothly along under leaden skies--perpetual, dim, dark clouds. Despite the brightness of the sun above them, the clouds made the light dim and gray. They reflected such an enormous percentage of the light that struck them that the climate was not as hot as they had feared.

The ground was dark under its somber mantle of clouds; the hills, the rivers that crawled across wide plains, and the oddly stunted forests all looked as though they had been modeled in a great ma.s.s of greenish-gray putty. It was a discouraging world.

"I'm glad we didn't wait for our swim here," remarked Wade. "It sure looks like rain."

Arcot stopped the ship and held it motionless at ten miles while Wade made his chemical a.n.a.lysis of the air. The report looked favorable; plenty of oxygen and a trace of carbon dioxide mixed with nitrogen.

"But the water vapor!" Wade said. "The air is saturated with it! It won't be the heat, but the humidity that'll bother us--to coin a phrase."

Arcot dropped the ship still farther, at the same time moving forward toward a sea he had seen in the distance. Swiftly, the ground sped beneath them. The low plain sloped toward the sea, a vast, level surface of gray, leaden water.

"Oh, brother, what a pleasant world," said Fuller sarcastically.

It was certainly not an inspiring scene. The leaden skies, the heavy clouds, the dark land, and the gray-green of the sea, always shaded in perpetual half-light, lest the burning sun heat them beyond endurance.

It was a gloomy world.

They turned and followed the coast. Still no sign of inhabitants was visible. Mile after mile pa.s.sed beneath them as the shining ship followed up the ragged sh.o.r.e. Small indentations and baylets ran into a shallow, level sea. This world had no moon, so it was tideless, except for the slight solar tides.

Finally, far ahead of them, and well back from the coast, Arcot spotted a great mountain range.

"I'm going to head for that," he told the others. "If these people are at war with our very inimical friends of the other planet, chances are they'll put their cities in the mountains, too."

They had such cities. The _Ancient Mariner_ had penetrated less than a hundred miles along the twisted ranges of the mountains before they saw, far ahead, a great, cone-shaped city. The city was taller, larger than those of the other planet, and the cone ran up farther from the actual city buildings, leaving the aircraft more room.

Arcot stopped and watched the city a long time through the telescope. It seemed similar to the others in all respects. The same type of needle-like ships floated in the air above it, and the same type of cone ray projectors nestled in the base of the city's invisible protection.

"We may as well take a chance," said Arcot. He shot the ship forward until they were within a mile of the city, in plain sight of the inhabitants.