The Starship Pandora creaked and groaned as her landing pads settled unevenly in the mucky surface of the ugly world outside. She seemed to be restless to end her fool's errand here, two hundred light years from the waiting hordes on Earth. Straining metal plates twanged and echoed through her hallways.

Captain Gwayne cursed and rolled over, reaching for his boots. He was a big, rawboned man, barely forty; but ten years of responsibility had pressed down his shoulders and put age-feigning hollows under his reddened eyes. The starlanes between Earth and her potential colonies were rough on the men who traveled them now. He shuffled toward the control room, grumbling at the heavy gravity.

Lieutenant Jane Corey looked up, nodding a blonde head at him as he moved toward the ever-waiting pot of murky coffee. "Morning, Bob. You need a shave."

"Yeah." He swallowed the hot coffee without tasting it, then ran a hand across the dark stubble on his chin. It could wait. "Anything new during the night?"

"About a dozen blobs held something like a convention a little ways north of us. They broke up about an hour ago and streaked off into the clouds." The blobs were a peculiarity of this planet about which nobody knew anything. They looked like overgrown fireballs, but seemed to have an almost sentient curiosity about anything moving on the ground. "And our two cadets sneaked out again. Barker followed them, but lost them in the murk. I've kept a signal going to guide them back."

Gwayne swore softly to himself. Earth couldn't turn out enough starmen in the schools, so promising kids were being shipped out for training as cadets on their twelfth birthday. The two he'd drawn, Kaufman and Pinelli, seemed to be totally devoid of any sense of caution.

Of course there was no obvious need for caution here. The blobs hadn't seemed dangerous, and the local animals were apparently all herbivorous and harmless. They were ugly enough, looking like insects in spite of their internal skeletons, with anywhere from four to twelve legs each on their segmented bodies. None acted like dangerous beasts.

But something had happened to the exploration party fifteen years back, and to the more recent ship under Hennessy that was sent to check up.

He turned to the port to stare out at the planet. The Sol-type sun must be rising, since there was a dim light. But the thick clouds that wrapped the entire world diffused its rays into a haze. For a change, it wasn't raining, though the ground was covered by thick swirls of fog. In the distance, the tops of shrubs that made a scrub forest glowed yellow-green. Motions around them suggested a herd of feeding animals. Details were impossible to see through the haze. Even the deep gorge where they'd found Hennessy's carefully buried ship was completely hidden by the fog.

There were three of the blobs dancing about over the grazing animals now, as they often seemed to do. Gwayne stared at them for a minute, trying to read sense into the things. If he had time to study them....

But there was no time.

Earth had ordered him to detour here, after leaving his load of deep-sleep stored colonists on Official World 71, to check on any sign of Hennessy. He'd been here a week longer than he should have stayed already. If there was no sign in another day or so of what had happened to the men who'd deserted their ship and its equipment, he'd have to report back.

He would have left before, if a recent landslip hadn't exposed enough of the buried ship for his metal locators to spot from the air by luck. It had obviously been hidden deep enough to foil the detectors originally.

"Bob!" Jane Corey's voice cut through his pondering. "Bob, there are the kids!"

Before he could swing to follow her pointing finger, movement caught his eye.

The blobs had left the herd. Now the three were streaking at fantastic speed to a spot near the ship, to hover excitedly above something that moved there.

He saw the two cadets then, heading back to the waiting ship, just beyond the movement he'd seen through the mist.

Whatever was making the fog swirl must have reached higher ground. Something began to heave upwards. It was too far to see clearly, but Gwayne grabbed the microphone, yelling into the radio toward the cadets.

They must have seen whatever it was just as the call reached them. Young Kaufman grabbed at Pinelli, and they swung around together.

Then the mists cleared.

Under the dancing blobs, a horde of things was heading for the cadets. Shaggy heads, brute bodies vaguely man-like! One seemed to be almost eight feet tall, leading the others directly toward the spacesuited cadets. Some of the horde were carrying spears or sticks. There was a momentary halt, and then the leader lifted one arm, as if motioning the others forward.

"Get the jeeps out!" Gwayne yelled at Jane. He yanked the door of the little officers' lift open and jabbed the down button. It was agonizingly slow, but faster than climbing down. He ripped the door back at the exit deck. Men were dashing in, stumbling around in confusion. But someone was taking over now—one of the crew women. The jeeps were lining up. One, at the front, was stuttering into life, and Gwayne dashed for it as the exit port slid back.

There was no time for suits or helmets. The air on the planet was irritating and vile smelling, but it could be breathed. He leaped to the seat, to see that the driver was Doctor Barker. At a gesture, the jeep rolled down the ramp, grinding its gears into second as it picked up speed. The other two followed.

There was no sign of the cadets at first. Then Gwayne spotted them; surrounded by the menacing horde. Seen from here, the things looked horrible in a travesty of manhood.

The huge leader suddenly waved and pointed toward the jeeps that were racing toward him. He made a fantastic leap backwards. Others swung about, two of them grabbing up the cadets. The jeep was doing twenty miles an hour now, but the horde began to increase the distance, in spite of the load of the two struggling boys! The creatures dived downward into lower ground, beginning to disappear into the mists.

"Follow the blobs," Gwayne yelled. He realized now he'd been a fool to leave his suit; the radio would have let him keep in contact with the kids. But it was too late to go back.

The blobs danced after the horde. Barker bounced the jeep downward into a gorge. Somewhere the man had learned to drive superlatively; but he had to slow as the fog thickened lower down.

Then it cleared to show the mob of creatures doubling back on their own trail to confuse the pursuers.

There was no time to stop. The jeep plowed through them. Gwayne had a glimpse of five-foot bodies tumbling out of the way. Monstrously coarse faces were half hidden by thick hair. A spear crunched against the windshield from behind, and Gwayne caught it before it could foul the steering wheel. It had a wickedly beautiful point of stone.

The creatures vanished as Barker fought to turn to follow them. The other jeeps were coming up, by the sound of their motors, but too late to help. They'd have to get to the group with the cadets in a hurry or the horde would all vanish in the uneven ground, hidden by the fog.

A blob dropped down, almost touching Gwayne.

He threw up an instinctive hand. There was a tingling as the creature seemed to pass around it. It lifted a few inches and drifted off.

Abruptly, Barker's foot ground at the brake. Gwayne jolted forward against the windshield, just as he made out the form of the eight-foot leader. The thing was standing directly ahead of him, a cadet on each shoulder.

The wheels locked and the jeep slid protestingly forward. The creature leaped back. But Gwayne was out of the jeep before it stopped, diving for the figure. It dropped the boys with a surprised grunt.

The arms were thin and grotesque below the massively distorted shoulders, but amazingly strong. Gwayne felt them wrench at him as his hands locked on the thick throat. A stench of alien flesh was in his nose as the thing fell backwards. Doc Barker had hit it seconds after the captain's attack. Its head hit rocky ground with a dull, heavy sound, and it collapsed. Gwayne eased back slowly, but it made no further move, though it was still breathing.

Another jeep had drawn up, and men were examining the cadets. Pinelli was either laughing or crying, and Kaufman was trying to break free to kick at the monster. But neither had been harmed. The two were loaded onto a jeep while men helped Barker and Gwayne stow the bound monster on another before heading back.

"No sign of skull fracture. My God, what a tough brute!" Barker shook his own head, as if feeling the shock of the monster's landing.

"I hope so," Gwayne told him. "I want that thing to live—and you're detailed to save it and revive it. Find out if it can make sign language or draw pictures. I want to know what happened to Hennessy and why that ship was buried against detection. This thing may be the answer."

Barker nodded grimly. "I'll try, though I can't risk drugs on an alien metabolism." He sucked in on the cigarette he'd dug out, then spat sickly. Smoke and this air made a foul combination. "Bob, it still makes no sense. We've scoured this planet by infra-red, and there was no sign of native villages or culture. We should have found some."

"Troglodytes, maybe," Gwayne guessed. "Anyhow, send for me when you get anything. I've got to get this ship back to Earth. We're overstaying our time here already."

The reports from the cadets were satisfactory enough. They'd been picked up and carried, but no harm had been done them. Now they were busy being little heroes. Gwayne sentenced them to quarters as soon as he could, knowing their stories would only get wilder and less informative with retelling.

If they could get any story from the captured creature, they might save time and be better off than trying to dig through Hennessy's ship. That was almost certainly spoorless by now. The only possible answer seemed to be that the exploring expedition and Hennessy's rescue group had been overcome by the aliens.

It was an answer, but it left a lot of questions. How could the primitives have gotten to the men inside Hennessy's ship? Why was its fuel dumped? Only men would have known how to do that. And who told these creatures that a space ship's metal finders could be fooled by a little more than a hundred feet of solid rock? They'd buried the ship cunningly, and only the accidental slippage had undone their work.

Maybe there would never be a full answer, but he had to find something—and find it fast. Earth needed every world she could make remotely habitable, or mankind was probably doomed to extinction.

The race had blundered safely through its discovery of atomic weapons into a peace that had lasted two hundred years. It had managed to prevent an interplanetary war with the Venus colonists. It had found a drive that led to the stars, and hadn't even found intelligent life there to be dangerous on the few worlds that had cultures of their own.

But forty years ago, observations from beyond the Solar System had finally proved that the sun was going to go nova.

It wouldn't be much of an explosion, as such things go—but it would render the whole Solar System uninhabitable for millenia. To survive, man had to colonize.

And there were no worlds perfect for him, as Earth had been. The explorers went out in desperation to find what they could; the terraforming teams did what they could. And then the big starships began filling worlds with colonists, carried in deep sleep to conserve space.

Almost eighty worlds. The nearest a four month journey from Earth and four more months back.

In another ten years, the sun would explode, leaving man only on the footholds he was trying to dig among other solar systems. Maybe some of the strange worlds would let men spread his seed again. Maybe none would be spawning grounds for mankind in spite of the efforts. Each was precious as a haven for the race.

If this world could be used, it would be nearer than most. If not, as it now seemed, no more time could be wasted here.

Primitives could be overcome, maybe. It would be ruthless and unfair to strip them of their world, but the first law was survival.

But how could primitives do what these must have done?

He studied the spear he had salvaged. It was on a staff made of cemented bits of smaller wood from the scrub growth, skillfully laminated. The point was of delicately chipped flint, done as no human hand had been able to do for centuries.

"Beautiful primitive work," he muttered.

Jane pulled the coffee cup away from her lips and snorted. "You can see a lot more of it out there," she suggested.

He went to the port and glanced out. About sixty of the things were squatting in the clearing fog, holding lances and staring at the ship. They were perhaps a thousand yards away, waiting patiently. For what? For the return of their leader—or for something that would give the ship to them?

Gwayne grabbed the phone and called Barker. "How's the captive coming?"

Barker's voice sounded odd.

"Physically fine. You can see him. But—"

Gwayne dropped the phone and headed for the little sick bay. He swore at Doc for not calling him at once, and then at himself for not checking up sooner. Then he stopped at the sound of voices.

There was the end of a question from Barker and a thick, harsh growling sound that lifted the hair along the nape of Gwayne's neck. Barker seemed to understand, and was making a comment as the captain dashed in.

The captive was sitting on the bunk, unbound and oddly unmenacing. The thick features were relaxed and yet somehow intent. He seemed to make some kind of a salute as he saw Gwayne enter, and his eyes burned up unerringly toward the device on the officer's cap.

"Haarroo, Cabbaan!" the thing said.

"Captain Gwayne, may I present your former friend, Captain Hennessy?" Barker said. There was a grin on the doctor's lips, but his face was taut with strain.

The creature nodded slowly and drew something from the thick hair on its head. It was the golden comet of a captain.

"He never meant to hurt the kids—just to talk to them," Barker cut in quickly. "I've got some of the story. He's changed. He can't talk very well. Says they've had to change the language around to make the sounds fit, and he's forgotten how to use what normal English he can. But it gets easier as you listen. It's Hennessy, all right. I'm certain."

Gwayne had his own ideas on that. It was easy for an alien to seize on the gold ornament of a captive earthman, even to learn a little English, maybe. But Hennessy had been his friend.

"How many barmaids in the Cheshire Cat? How many pups did your oldest kid's dog have? How many were brown?"

The lips contorted into something vaguely like a smile, and the curiously shaped fingers that could handle no human-designed equipment spread out.

Three. Seven. Zero.

The answers were right.

By the time the session was over, Gwayne had begun to understand the twisted speech from inhuman vocal cords better. But the story took a long time telling.

When it was finished, Gwayne and Barker sat for long minutes in silence. Finally Gwayne drew a shuddering breath and stood up. "Is it possible, Doc?"

"No," Barker said flatly. He spread his hands and grimaced. "No. Not by what I know. But it happened. I've looked at a few tissues under the microscope. The changes are there. It's hard to believe about their kids. Adults in eight years, but they stay shorter. It can't be a hereditary change—the things that affect the body don't change the germ plasm. But in this case, what changed Hennessy is real, so maybe the fact that the change is passed on is as real as he claims."

Gwayne led the former Hennessy to the exit. The waiting blobs dropped down to touch the monstrous man, then leaped up again. The crowd of monsters began moving forward toward their leader. A few were almost as tall as Hennessy, but most were not more than five feet high.

The kids of the exploring party....

Back in the control room, Gwayne found the emergency release levers, set the combinations and pressed the studs. There was a hiss and gurgle as the great tanks of fuel discharged their contents out onto the ground where no ingenuity could ever recover it to bring life to the ship again.

He'd have to tell the men and women of the crew later, after he'd had time to organize things and present it all in a way they could accept, however much they might hate it at first. But there was no putting off giving the gist of it to Jane.

"It was the blobs," he summarized it. "They seem to be amused by men. They don't require anything from us, but they like us around. Hennessy doesn't know why. They can change our cells, adapt us. Before men came, all life here had twelve legs. Now they're changing that, as we've seen.

"And they don't have to be close to do it. We've all been outside the hull. It doesn't show yet—but we're changed. In another month, Earth food would kill us. We've got to stay here. We'll bury the ships deeper this time, and Earth won't find us. They can't risk trying a colony where three ships vanish, so we'll just disappear. And they'll never know."

Nobody would know. Their children—odd children who matured in eight years—would be primitive savages in three generations. The Earth tools would be useless, impossible for the hands so radically changed. Nothing from the ship would last. Books could never be read by the new eyes. And in time, Earth wouldn't even be a memory to this world.

She was silent a long time, staring out of the port toward what must now be her home. Then she sighed. "You'll need practice, but the others don't know you as well as I do, Bob. I guess we can fix it so they'll believe it all. And it's too late now. But we haven't really been changed yet, have we?"

"No," he admitted. Damn his voice! He'd never been good at lying. "No. They have to touch us. I've been touched, but the rest could go back."

She nodded. He waited for the condemnation, but there was only puzzlement in her face. "Why?"

And then, before he could answer, her own intelligence gave her the same answer he had found for himself. "The spawning ground!"

It was the only thing they could do. Earth needed a place to plant her seed, but no world other than Earth could ever be trusted to preserve that seed for generation after generation. Some worlds already were becoming uncertain.

Here, though, the blobs had adapted men to the alien world instead of men having to adapt the whole planet to their needs. Here, the strange children of man's race could grow, develop and begin the long trek back to civilization. The gadgets would be lost for a time. But perhaps some of the attitudes of civilized man would remain to make the next rise to culture a better one.

"We're needed here," he told her, his voice pleading for the understanding he couldn't yet fully give himself. "These people need as rich a set of bloodlines as possible to give the new race strength. The fifty men and women on this ship will be needed to start them with a decent chance. We can't go to Earth, where nobody would believe or accept the idea—or even let us come back. We have to stay here."

She smiled then and moved toward him, groping for his strength. "Be fruitful," she whispered. "Be fruitful and spawn and replenish an earth."

"No," he told her. "Replenish the stars."

But she was no longer listening, and that part of his idea could wait.

Some day, though, their children would find a way to the starlanes again, looking for other worlds. With the blobs to help them, they could adapt to most worlds. The unchanged spirit would lead them through all space, and the changing bodies would claim worlds beyond numbering.

Some day, the whole universe would be a spawning ground for the children of men!