Lockley had seen it headed up to the lake the day before the landing.

Now he found himself wondering sardonically to what degree the Wild Life Control men determined where mountain lions should hunt.

He'd slept in the open innumerable times without thinking of mountain lions. With Jill to look after, though, he worried. But he was horribly weary, and he knew somehow that in the back of his mind there was something unpleasant that was trying to move into his conscious thoughts. It was a sort of hunch. Wearily and half asleep, he tried to put his mind on it. He failed.

He awoke suddenly. There were rustlings among the trees. Something moved slowly and intermittently toward him. It could be anything, even a creature from Boulder Lake. He heard other sounds. Another creature.

The first drew near, not moving in a straight line. The second creature followed it, drawing closer to the first.

Lockley's scalp crawled. Creatures from s.p.a.ce might have some of the highly-developed senses which men had lost while growing civilized--full keenness of scent, for example.

Such a creature might be able to find Lockley and Jill in the darkness after trailing them for miles. And so primitive a talent, in a creature farther advanced than men, was somehow more horrifying than anything else Lockley had thought of about them. He gripped his club desperately, wholly aware that a star creature should be able to paralyze him with the terror beam....

There were whistling, squealing noises. They were very much like the squeaks his captors had directed at each other and at him when he was blindfolded and being led downhill to imprisonment in the compost pit sh.e.l.l. Very much like, but not identical. Nevertheless, Lockley's hair seemed to stand up on end and he raised his club in desperation.

The whistling squeals grew shriller. Then there was an indescribable sound and one of the two creatures rushed frantically away. It traveled in great leaps through the blackness under the trees.

And then there was a sudden whiff of a long-familiar odor, smelled a hundred times before. It was the reek of a skunk, stalked by a carnivore and defending itself as skunks do. But a skunk was nothing like a terror beam. Its effluvium offended only one sense, affected only one set of sensation nerves. The terror beam....

Lockley opened his mouth to laugh, but did not. The thing at the back of his mind had come forward. He was appalled.

Jill said shakily, "What's the matter? What's happened? That smell--"

"It's only a skunk," said Lockley evenly. "He just told me some very bad news. I know how the terror beam works now. And there's not a thing that can be done about it. Not a thing. It can't be!"

He raged suddenly, there in the darkness, because he saw the utter hopelessness of combatting the creatures who'd taken over Boulder Lake. There was nothing to keep them from taking over the whole earth, no matter what sort of monsters or not-monsters they might be.

CHAPTER 6

It was nine o'clock at night when Lockley killed the porcupine, and ten by the time Jill had gone back to sleep huddled between the projecting roots of a giant tree. Shortly after midnight Lockley had been awakened when a skunk defeated a hungry predator within a hundred yards of their bivouac. But some time in between, there was another happening of much greater importance elsewhere.

Something came out of Boulder Lake National Park. All humans had supposedly fled from it. It was abandoned to the creatures of the thing from the sky. But something came out of it.

n.o.body saw the thing, of course. n.o.body could approach it, which was the point immediately demonstrated. No human being could endure being within seven miles of whatever it was. It was evidently a vehicle of some sort, however, because it swung terror beams before it, and terror beams on either side, and when it was clear of the Park it played terror beams behind it, too. Men who suffered the lightest touch of those sweeping beams of terror and anguish moved frantically to avoid having the experience again. So when something moved out of the Park and sent wavering terror beams before it, men moved to one side or the other and gave it room.

On a large-scale map in the military area command post, its progress could be watched as it was reported. The reports described a development of unbearable beam strength which showed up as a bulge in the cordon's roughly circular line. That bulge, which was the cordon itself moving back, moved outward and became a half-circle some miles across. It continued to move outward, and on the map it appeared like a pseudopod extruded by an enormous amoeba. It was the area of effectiveness of a weapon previously unknown on earth--the area where humans could not stay.

Deliberately, the unseen moving thing severed itself from the similar and larger weapon field which was its birthplace and its home. It moved with great deliberation toward the small town of Maplewood, twenty miles from the border of the Park.

Jeeps and motorcycles scurried ahead of it, just out of reach of its beams. They made sure that houses and farms and all inhabited places were emptied of people before the moving terror beams could engulf them. They went into the town of Maplewood itself and frantically made sure that nothing alive remained in it. They went on to clear the countryside beyond.

The unseen thing from the Park moved onward. High overhead there was a dull muttering like faraway thunder, but it was planes with filled bomb racks circling above the starlit land. There were men in those planes who ached to dive down and destroy this separated fraction of an invasion. But there were firm orders from the Pentagon. So long as the invaders killed n.o.body, they were not to be attacked. There was reason for the order in the desire of the government to be on friendly terms with a race which could travel between the stars. But there was an even more urgent reason. The aliens had not yet begun to murder, but it was suspected that they had a horrifying power to kill. So it was firmly commanded that no bomb or missile or bullet was to be used unless the invaders invited hostilities by killing humans. Their captives--the crew of a helicopter--might be freed if aliens and men achieved friendship. So for now--no provocation!

The thing which n.o.body saw moved comfortably over the ground between the park and Maplewood. In the center of the weapon field there was a something which generated the terror beam and probably carried pa.s.sengers. Whatever it was, it moved onward and into Maplewood and for seven miles in every direction troops watched for it to move out again. Artillerymen had guns ready to fire upon it if they ever got firing coordinates and permission to go into action. Planes were ready to drop bombs if they ever got leave to do so. And a few miles away there were rockets ready to prove their accuracy and devastating capacity if only given a launching command. But nothing happened. Not even a flare was permitted to be dropped by the planes far up in the sky. A flare might be taken for hostility.

The thing from the Park stayed in Maplewood for two hours. At the end of that time it moved deliberately back toward the Park. It left the town untouched save for certain curious burglaries of hardware stores and radio shops and a garage or two. It looked as if intensely curious not-human beings had moved from their redoubt--Boulder Lake--to find out what civilization human beings had attained. They could guess at it by the buildings and the homes, but most notably in the technical shops of the inhabitants.

It went slowly and deliberately back into the Park. Humans moved cautiously back into the area that had been emptied. Not many, but enough to be sure that the thing had really returned to the place from which it had come. Soldiers were tentatively entering the again-abandoned town of Maplewood when the unseen thing changed the range of its weapon bearing on that little city. It was then presumably not less than seven miles on its way back to Boulder Lake.

The military had congratulated themselves on what they'd learned. The beam projectors at the lake had a range of much more than seven miles, but this movable, unidentifiable thing carried a lesser armament. From it, men and animals seven miles away were safe. This was notable news.

Then the unseen object did something. The terror beam that flicked back and forth doubled in intensity. The soldiers just reentering Maplewood smelled foulness and saw bright lights. Bellowings deafened them. They fell with every muscle rigid in spasm. Beyond them other men were paralyzed. For five minutes the invaders' mobile weapon paralyzed all living things for a distance of fifteen miles. Then for thirty seconds it paralyzed living things for a distance of thirty miles. For a bare instant it convulsed men and animals for a greater distance yet. And all these victims of the terror beam knew, thereafter, an invincible horror of the beam.

The thing from the Park which n.o.body had seen went back into the Park.

And then men were permitted to return to exactly the same places they'd been allowed to occupy before the thing began its excursion.

It seemed that nothing was changed, but everything was changed. If there were mobile carriers of the invasion weapon, then victory could not be had by a single atom bomb fired into Boulder Lake. There might be a dozen separate mobile terror beam generators scattered through the Park. Any atomic attack would need to be multiplied in its violence to be certain of results. Instead of one bomb there might be a need for fifty. They would have to destroy the Park utterly, even its mountains. And the fallout from so many atom bombs simply could not be risked. The invaders were effectively invulnerable.

While this undesirable situation was being demonstrated, Jill slept heavily between two roots of a very large tree, and Lockley dozed against a nearby tree trunk. He believed that he guarded Jill most vigilantly.

He awoke at dawn with the din of bird song in his ears. Jill opened her eyes at almost the same instant. She smiled at him and tried to get up. She was stiff and sore from the hardness of the ground on which she'd slept. But it was a new day, and there was breakfast. It was porcupine cooked the night before.

"Somehow," said Jill as she nibbled at a bone, "somehow I feel more cheerful than I did."

"That's a mistake," Lockley told her. "Start out with a few premonitions and the day improves as they turn out wrong. But if you start out hoping, the day ends miserably with most of your hopes denied."

"You've got premonitions?" she asked.

"Definitely," he said.

It was true. As yet he knew nothing of last night's temporary occupation of a human town, but he believed he knew how the terror beam worked even if he couldn't figure out a way to generate it. He could imagine no defense against it. But if Jill had awakened feeling cheerful, there was no reason to depress her. She'd have reason enough to be dejected later, beginning with proof of Vale's death and going on from there.

"We might listen to the news," she suggested. "A premonition or two might be ruled out right away!"

Silently, he turned on the little radio. Automatically, he set it for the lowest volume they could hear distinctly.

The main item in the news was a baldly factual but toned-down report of the thing from the lake which had left the park and examined a small human town in detail and then had returned to the Park. There were reports of peculiar hoofprints found where the invaders had been.

They were not the hoofprints of any earthly animal. There was an optimistic report from the scientists at work on the problem of the beam. Someone had come up with an idea and some calculations which seemed to promise that the beam would presently be duplicated. Once it was duplicated, of course a way to neutralize it could be found.

Lockley grunted. The broadcast was enthusiastic in its comments on the scientists. It talked gobbledegook which sounded as if it meant something but was actually nonsense. It barely touched on the fact that human beings were now ordered out of a much larger s.p.a.ce than had been evacuated before. There was a statement from an important official that panic buying of food was both unnecessary and unwise.

Lockley grunted again when the newscast ended.

"The idea that anything that can be duplicated can be canceled," he announced gloomily, "is unfortunately rot. We can duplicate sounds, but there's no way to make them cancel out! Not accurately!"

Jill had eaten a substantial part of the porcupine while the newscast was on. It was not a satisfying breakfast, but it cheered her immensely after two days of near-starvation.

"But," she observed, "maybe that won't apply to this business when you report what you know. It's not likely that anybody else has stood just outside a beam and made tests of what it's like and how it's aimed and so on."

They started off. For journeying in the Park, Lockley had the advantage that as part of the preparation for making a new map, he'd familiarized himself with all mapping done to date. He knew very nearly where he was. He knew within a close margin just where the terror beam stretched. He'd smashed his watch, which during sunshine subst.i.tuted admirably for a compa.s.s, but he could maintain a reasonably straight line toward that part of the Park's border the terror beam would cross.

They moved doggedly over mountain-flanks and up valleys, and once they followed a winding hollow for a long way because it led toward their destination without demanding that they climb. It was in this area that, pushing through brushwood beside a running stream, they came abruptly upon a big brown bear. He was no more than a hundred feet away. He stared at them inquisitively, raising his nose to sniff for their scent.

Lockley bent and picked up a stone. He threw it. It clattered on rocks on the ground. The bear made a whuffing sound and moved aggrievedly away.

"I'd have been afraid to do that," said Jill.

"It was a he-bear," said Lockley. "I wouldn't have tried it on a she-bear with cubs."