CHAPTER 1 .

The planet did not look promising, but they had no choice. When a ship's drive blows between star-systems, it has to be fixed. If metal parts must be recast and machined, and burned-out wiring has to be pieced together and insulated by hand, the job takes literally months. And if, then, getting home is a matter of more months of journeying with a drive that still limps, while coughing and cutting off for seconds or until it is tinkered with—why, the traveler has to find some way to renew his food supply.

It is for such occasions that the Interstellar Code requires all ships to carry an emergency kit with seeds and agricultural directions.

The Danaë, therefore, limped to the nearest Sol-type star to hunt for a planet on which to plant some crops. There was Borden and his wife, Ellen. There was Sattell, whom they would be glad to part with when they got home. There was Jerry, who was diffident enough to be tolerable in spite of his lack of years. They were all at the forward vision-port when they approached the only possible planet.

"It's fifty million miles out," Borden said. "A bit on the hot side. But the sun is smaller than Sol, so it may not be too bad. At least there are polar caps—small ones."

"No seas," Sattell said. "Pretty barren."

The others said nothing. It did not look at all encouraging.

The Danaë went in on a spiral descending orbit. Borden looked for other planets. He found a gas giant with a high-speed rotation. It was flattened, oblate. He checked it with the two polar caps on the nearer world and said worriedly:

"If the ecliptic's where I think it is, there'll be no seasons to speak of. I was hoping this planet was near its equinox, because the ice-caps are so nearly the same size."

Ellen said absorbedly, "I think I see a tinge of olive-green around that ice-cap. The smaller one."

"Probably vegetation," agreed her husband. "But I don't see any more. The place does look to be mostly desert."

They went in closer, circling as they headed for atmosphere.

Then Jerry said diffidently: "Could that be ice, there?"

There was a white spot in the middle of the sandy-colored northern hemisphere. It was the size of a pin head to the naked eye. Borden swung a telescope on it. They were nearly above the point now, where day turned into night.

The sunlight fell upon the white spot at a flat angle. If the whiteness were perpetual snow on the tops of mountains, the mountains should cast shadows. But Borden could not make out shadows near the white. Automatically he snapped the telecamera before he gave up the effort to understand the white spot.

"I doubt it's snow," he said. "I don't know what it is."

"Surely you can make a guess!" said Sattell, with that elaborate courtesy which was getting on everyone's nerves.

"I can't," Borden said briefly.

The ship moved to the dark side of the planet, and presently plunged into its shadow.

They went on for hours, watching for lights. There were none. When they came out to sunlight again they had descended a long way during their time in the planet's night.

They could see that the surface of the planet was pure tumbled sand dunes with occasional showings of stone. They were three-quarters of the way around when they saw the white spot again. This time they were no more than four or five hundred miles high. They could tell its size.

It was all of three hundred miles long, north and south, and from fifty to seventy-five miles wide. There were thin hair-lines running from it, remarkably straight on the whole, to the north and south. They were very, very fine lines. The patch was still white. As they came to be in line between it and the sun, their shadow would have passed almost over it.

The white spot changed abruptly. One instant it was white, the next, a patch of it had turned silver. That silvery appearance spread out and out in a swift rippling motion. The patch became silver all over its entire surface. Then it turned to flame.

There was a screaming of alarm gongs. The emergency feed-back screens went on and everything went black outside. The lights in the ship dimmed down to mere dull-red glows. There was silence.

The ports showed blackness. The drive, of course, ceased to operate. The ship had sealed itself in a shell of screening, through which nothing at all could penetrate, but which drew upon the ship's power-tanks for as much energy as it neutralized outside. And the drain was so great that the interior lights were dim red spots and not lights at all.

For five heart-beats the blackness persisted while the four in the ship stayed frozen.

The feed-back screen cut off. Again they saw the planet below. The white patch once more was white, instead of flame. But as they looked, the silvery look spread out all over it in glittering ripples, and they seemed to look into the heart of a sun's ravening furnaces before the feed-back screen came into existence for their defense. The ports were blacked out again.

The ship hurtled on toward emptiness. It was blind. It was helpless.

Borden moved an emergency light to shine on the output meter. The needle was fast against the pin. The feed-back screen was not only drawing maximum safe power. It was working on an effective short circuit of the ship's entire power supply. Busbars carrying that current would be heating up. They would melt at any instant.

Borden's fingers moved swiftly. He set up a shunt for on-switch operation of the feed-back field.

He threw the last cross-over tumbler and waited, with sweat beading his forehead. Something had flung a beam of pure heat-energy at the Danaë. It should have volatized the small space-craft immediately, but it had been left on for four seconds.

When it ended, the feed-back screen cut off, too. Then the Danaë had been detected a second time and the planetary weapon used again. Now, with the feed-back field on-switch instead of relay, if the heat ray turned off again the feed-back field wouldn't, and the Danaë should be indetectable to anything but a permeability probe. The space-ship would seem to have been destroyed, if the heat-beam went off before the ship's power failed.

It did. A relay clicked somewhere, cut a current flow of some tens of thousands of amperes. The lights inside the ship flashed to full brightness. Borden's eyes flicked to the power-meters. The operational power-tank meter read zero. The emergency reserve power-tank meter showed a reading that made fresh sweat come out on Borden's face.

But the ports stayed black. Absolutely any form of energy striking the feed-back field outside would be neutralized. No light would be reflected. Any detector-field would be exactly canceled, as if nothing whatever existed where the Danaë hurtled onward some few hundred miles above the planet's surface.

The Danaë, at the moment, was in the position of having made a hole about itself to crawl into. But it couldn't use its drive. It couldn't see out. It was hiding in blackness of its own creation, like a cuttlefish in its own ink.

"Dee," Ellen Borden asked her husband in a shaky voice, "what happened?"

"Something threw a heat-ray at us," said Borden. He mopped his forehead. "We should have exploded to incandescent gas. But our feed-back field stopped it. The heat-ray cut off when we should have been destroyed—and so did our field, so there we were again! And so we got a second beaming. But now we aren't. At least we appear not to be. So we can live until we crash."

Sattell said in a suddenly high-pitched voice, "How long will that be?"

"I don't know the gravity," Borden told him. "But it does take time to fall four hundred miles. We have some velocity, too. It's under orbital speed but it'll help. I'm going to figure something out."

He swung in the control-chair and hit keys on the computer. The size of the white spot. It had all turned silvery, then all of it had flamed. Why? The amount of power in the heat-ray—a rough guess. Nobody could have figures on what a ship's tanks would yield on short-circuit, but the field had had to neutralize some hundreds of megawatts of pure heat.

The amount of overlap—the size of the heat-ray itself—was another guess and a wild one. And why had all of the white spot spat flame? Every bit of it? Three hundred miles by an average of sixty.... Even at low power—

The computer clicked.

"Sun-power," Borden said grimly, after a moment. "That figures out just about right. Not more than a kilowatt to the square yard, but eighteen thousand square miles has plenty of square yards! We've been on the receiving end of a sun-mirror heat-ray, and if it had been accurately figured we'd have fried." Then he said, "But a sun-mirror doesn't work at night!"

He punched keys again. Presently he looked at his wrist-chronometer. He waited.

"We're falling!" Sattell cried shrilly. "Do something!"

"Forty seconds more," said Borden. "I'm gambling your life, Sattell, but I'm gambling Ellen's and mine too, not to mention Jerry's. Calm down."

His eyes turned to the meter that showed the feed-back-field drain. It was drawing precisely the amount of power needed to cancel out the sunlight falling on it, as well as the starlight, and the light reflected from the day side of the world below them. That drain was less than it had been. They were crossing the planet's terminator—the line dividing the light side from the dark side—as they plunged toward the sandy deserts.

The drain dropped abruptly. They had moved into the planet's shadow. Into night.

Instantly, Borden flicked off the feed-back field. His eyes darted to the nearest object radar dial. They were still sixty miles high, but falling at a tremendous speed. Borden's hands moved quickly over the controls. Lift. Full atmosphere drive on a new course.

"We won't crash," he said evenly, "unless we're shot at with something that works in the dark. But that sun-mirror business is odd. There's only a certain size of sun-mirror that's economical. When they get too big there are better weapons for the money. That one was big! So maybe it's the best weapon this planet has. In which case we'll be nearest safety at one of the ice-caps. Sun-mirrors will be handicapped in polar regions!"

"They—tried to kill us!" Sattell panted suddenly. "They don't like strangers! They fired on us without warning! We can't land on this planet! We've got to go on!"

"If you want to know," Borden told him, "we haven't any fuel to go on with. And we happen to be short of food. And did you remember—"

The ship's drive cut off. It had been burnt out and repaired by hand, with inevitable drawbacks. Since the repair, it had run steadily for as long as three days at a time. But also it had stopped four times in one hour, and it had needed tinkering with three times in one day.

It ought to be overhauled. For now it had cut off, and they were forty miles high. If it came on again they would live; if it didn't, they wouldn't.

After six spine-chilling seconds the drive came on again. Ten minutes later it went off for two seconds. Half an hour later it made that ominous hiccoughing which presaged immediate and final failure. But it didn't fail.

It was not pleasant to be so close to a planet they could not afford to leave, with a drive that threatened to give up the ghost at any instant, and with something on the planet which had used a sun-mirror beam to try to volatilize the Danaë without parley. Apparently the four in the small ship had the choice of dying on this planet or not too far away in space. They needed food, and they needed fuel. Above all, if the planet was inhabited, they needed friendship, and they weren't likely to get it.

They were only ten miles high when signs of dawn appeared ahead. Of course, if they happened to be moving with the planet's rotation, they'd be moving into sunset from the night. They didn't know. Not yet. But there were gray clouds ahead, to the right and below.

A little later they were five miles high and the clouds were still below. There was twilight ahead. At two miles altitude the drive hesitated for a moment, and caught again after all four in the control room had stopped breathing.

Red sunlight appeared before the ship in a spreading, sprawling thin line. At five thousand feet the ship had slowed to a bare crawl—a few hundred miles an hour. And the dawn came up like thunder.