On the morning the radar reported something odd out in space, Lockley awoke at about twenty minutes to eight. That was usual. He'd slept in a sleeping bag on a mountain-flank with other mountains all around. That was not unprecedented. He was there to make a base line measurement for a detailed map of the Boulder Lake National Park, whose facilities were now being built. Measuring a base line, even with the newest of electronic apparatus, was more or less a commonplace job for Lockley.

This morning, though, he woke and realized gloomily that he'd dreamed about Jill Holmes again, which was becoming a habit he ought to break. He'd only met her four times and she was going to marry somebody else. He had to stop.

He stirred, preparatory to getting up. At the same moment, certain things were happening in places far away from him. As yet, no unusual object in space had been observed. That would come later. But far away up at the Alaskan radar complex a man on duty watch was relieved by another. The relief man took over the monitoring of the giant, football-field-sized radar antenna that recorded its detections on magnetic tape. It happened that on this particular morning only one other radar watched the skies along a long stretch of the Pacific Coast. There was the Alaskan installation, and the other was in Oregon. It was extremely unusual for only those two to be operating. The people who knew about it, or most of them, thought that official orders had somehow gone astray. Where the orders were issued, nothing out of the ordinary appeared. All was normal, for example, in the Military Information Center in Denver. The Survey saw nothing unusual in Lockley's being at his post, and other men at places corresponding to his in the area which was to become Boulder Lake National Park. It also seemed perfectly natural that there should be bulldozer operators, surveyors, steelworkers, concrete men and so on, all comfortably at breakfast in the construction camp for the project. Everything seemed normal everywhere.

Up to the time the Alaskan installation reported something strange in space, the state of things generally was neither alarming nor consoling. But at 8:02 a.m. Pacific time, the situation changed. At that time Alaska reported an unscheduled celestial object of considerable size, high out of atmosphere and moving with surprising slowness for a body in space. Its course was parabolic and it would probably land somewhere in South Dakota. It might be a bolide—a large, slow-moving meteorite. It wasn't likely, but the entire report was improbable.

The message reached the Military Information Center in Denver at 8:05 a.m. By 8:06 it had been relayed to Washington and every plane on the Pacific Coast was ordered aloft. The Oregon radar unit reported the same object at 8:07 a.m. It said the object was seven hundred fifty miles high, four hundred miles out at sea, and was headed toward the Oregon coastline, moving northwest to southeast. There was no major city in its line of travel. The impact point computed by the Oregon station was nowhere near South Dakota. As other computations followed other observations, a second place of fall was calculated, then a third. Then the Oregon radar unbelievably reported that the object was decelerating. Allowing for deceleration, three successive predictions of its landing point agreed. The object, said these calculations, would come to earth somewhere near Boulder Lake, Colorado, in what was to become a national park. Impact time should be approximately 8:14 a.m.

These events followed Lockley's awakening in the wilds, but he knew nothing of any of them. He himself wasn't near the lake, which was to be the center of a vacation facility for people who liked the outdoors. The lake was almost circular and was a deep, rich blue. It occupied what had been the crater of a volcano millions of years ago. Already bulldozers had ploughed out roads to it through the forest. Men worked with graders and concrete mixers on highways and on bridges across small rushing streams. There was a camp for them. A lakeside hotel had been designed and stakes were driven in the ground where its foundation would eventually be poured. There were infant big-mouthed bass in the lake and fingerling trout in many of the streams. A huge Wild Life Control trailer-truck went grumbling about such trails as were practical, attending to these matters. Yesterday Lockley had seen it gleaming in bright sunshine as it moved toward Boulder Lake on the highway nearest to his station.

But that was yesterday. This morning he awoke under a pale gray sky. There was complete cloud cover overhead. He smelled conifers and woods-mould and mountain stone in the morning. He heard the faint sound of tree branches moving in the wind. He noted the cloud cover. The clouds were high, though. The air at ground level was perfectly transparent. He turned his head and saw a prospect that made being in the wilderness seem entirely reasonable and satisfying.

Mountains reared up in every direction. A valley lay some thousands of feet below him, and beyond it other valleys, and somewhere a stream rushed white water to an unknown destination. Not many wake to such a scene.

Lockley regarded it, but without full attention. He was preoccupied with thoughts of Jill Holmes, and unfortunately she was engaged to marry Vale, who was also working in the park some thirty miles to the northeast, near Boulder Lake itself. Lockley didn't know him well since he was new in the Survey. He was up there to the northeast with an electronic survey instrument like Lockley's and on the same job. Jill had an assignment from some magazine or other to write an article on how national parks are born, and she was staying at the construction camp to gather material. She'd learned something from Vale and much from the engineers while Lockley had tried to think of interesting facts himself. He'd failed. When he thought about her, he thought about the fact that she was engaged to Vale. That was an unhappy thought. Then he tried to stop thinking about her altogether. But his mind somehow lingered on the subject.

At ten minutes to eight Lockley began to dress, wilderness fashion. He began by putting on his hat. It had lain on the pile of garments by his bed. Then he donned the rest of his garments in the exact reverse of the order in which he'd removed them.

At 8:00 he had a small fire going. He had no premonition that anything out of the ordinary was going to happen that day. This was still before the first Alaskan report. At 8:10 he had bacon sizzling and a small coffeepot almost enveloped by the flames. Events occurred and he knew nothing at all about them. For example, the Military Information Center had been warned of what was later privately called Operation Terror while Lockley was still tranquilly cooking breakfast and thinking—frowning a little—about Jill.

Naturally he knew nothing of emergency orders sending all planes aloft. He wasn't informed about something reported in space and apparently headed for an impact point at Boulder Lake. As the computed impact time arrived, Lockley obliviously dumped coffee into his tin coffeepot and put it back on the flames.

At 8:13 instead of 8:14—this information is from the tape records—there was an extremely small earth shock recorded by the Berkeley, California, seismograph. It was a very minor shock, about the intensity of the explosion of a hundred tons of high explosive a very long distance away and barely strong enough to record its location, which was Boulder Lake. The cause of that explosion or shock was not observed visually. There'd been no time to alert observers, and in any case the object should have been out of atmosphere until the last few seconds of its fall, and where it was reported to fall the cloud cover was unbroken. So nobody reported seeing it. Not at once, anyhow, and then only one man.

Lockley did not feel the impact. He was drinking a cup of coffee and thinking about his own problems. But a delicately balanced rock a hundred yards below his camp site toppled over and slid downhill. It started a miniature avalanche of stones and rocks. The loose stuff did not travel far, but the original balanced rock bounced and rolled for some distance before it came to rest.

Echoes rolled between the hillsides, but they were not very loud and they soon ended. Lockley guessed automatically at half a dozen possible causes for the small rock-slide, but he did not think at all of an unperceived temblor from a shock like high explosives going off thirty miles away.

Eight minutes later he heard a deep-toned roaring noise to the northeast. It was unbelievably low-pitched. It rolled and reverberated beyond the horizon. The detonation of a hundred tons of high explosives or an equivalent impact can be heard for thirty miles, but at that distance it doesn't sound much like an explosion.

He finished his breakfast without enjoyment. By that time well over three-quarters of the Air Force on the Pacific Coast was airborne and more planes shot skyward instant after instant. Inevitably the multiplied air traffic was noted by civilians. Reporters began to telephone airbases to ask whether a practice alert was on, or something more serious.

Such questions were natural, these days. All the world had the jitters. To the ordinary observer, the prospects looked bad for everything but disaster. There was a crisis in the United Nations, which had been reorganized once and might need to be shuffled again. There was a dispute between the United States and Russia over satellites recently placed in orbit. They were suspected of carrying fusion bombs ready to dive at selected targets on signal. The Russians accused the Americans, and the Americans accused the Russians, and both may have been right.

The world had been so edgy for so long that there were fallout shelters from Chillicothe, Ohio, to Singapore, Malaya, and back again. There were permanent trouble spots at various places where practically anything was likely to happen at any instant. The people of every nation were jumpy. There was constant pressure on governments and on political parties so that all governments looked shaky and all parties helpless. Nobody could look forward to a peaceful old age, and most hardly hoped to reach middle age. The arrival of an object from outer space was nicely calculated to blow the emotional fuses of whole populations.

But Lockley ate his breakfast without premonitions. Breezes blew and from every airbase along the coast fighting planes shot into the air and into formations designed to intercept anything that flew on wings or to launch atom-headed rockets at anything their radars could detect that didn't.

At eight-twenty, Lockley went to the electronic base line instrument which he was to use this morning. It was a modification of the devices used to clock artificial satellites in their orbits and measure their distance within inches from hundreds of miles away. The purpose was to make a really accurate map of the park. There were other instruments in other line-of-sight positions, very far away. Lockley's schedule called for them to measure their distances from each other some time this morning. Two were carefully placed on bench marks of the continental grid. In twenty minutes or so of cooperation, the distances of six such instruments could be measured with astonishing precision and tied in to the bench marks already scattered over the continent. Presently photographing planes would fly overhead, taking overlapping pictures from thirty thousand feet. They would show the survey points and the measurements between them would be exact, the photos could be used as stereo-pairs to take off contour lines, and in a few days there would be a map—a veritable cartographer's dream for accuracy and detail.

That was the intention. But though Lockley hadn't heard of it yet, something was reported to have landed from space, and a shock like an impact was recorded, and all conditions would shortly be changed. It would be noted from the beginning, however, that an impact equal to a hundred-ton explosion was a very small shock for the landing of a bolide. It would add to the plausibility of reported deceleration, though, and would arouse acute suspicion. Justly so.

At 8:20, Lockley called Sattell who was southeast of him. The measuring instruments used microwaves and gave readings of distance by counting cycles and reading phase differences. As a matter of convenience the microwaves could be modulated by a microphone, so the same instrument could be used for communication while measurements went on. But the microwaves were directed in a very tight beam. The device had to be aimed exactly right and a suitable reception instrument had to be at the target if it was to be used at all. Also, there was no signal to call a man to listen. He had to be listening beforehand, and with his instrument aimed right, too.

So Lockley flipped the modulator switch and turned on the instrument. He said patiently, "Calling Sattell. Calling Sattell. Lockley calling Sattell."

He repeated it some dozens of times. He was about to give it up and call Vale instead when Sattell answered. He'd slept a little later than Lockley. It was now close to nine o'clock. But Sattell had expected the call. They checked the functioning of their instruments against each other.

"Right!" said Lockley at last. "I'll check with Vale and on out of the park, and then we'll put it all together and wrap it up and take it home."

Sattell agreed. Lockley, rather absurdly, felt uncomfortable because he was going to have to talk to Vale. He had nothing against the man, but Vale was, in a way, his rival although Jill didn't know of his folly and Vale could hardly guess it.

He signed off to Sattell and swung the base line instrument to make a similar check with Vale. It was now ten minutes after nine. He aligned the instrument accurately, flipped the switch, and began to say as patiently as before, "Calling Vale. Calling Vale. Lockley calling Vale. Over."

He turned the control for reception. Vale's voice came instantly, scratchy and hoarse and frantic.

"Lockley! Listen to me! There's no time to tell me anything. I've got to tell you. Something came down out of the sky here nearly an hour ago. It landed in Boulder Lake, and at the last instant there was a terrific explosion and a monstrous wave swept up the shores of the lake. The thing that came down vanished under water. I saw it, Lockley!"

Lockley blinked. "Wha-a-at?"

"A thing came down out of the sky!" panted Vale. "It landed in the lake with a terrific explosion. It went under. Then it came up to the surface minutes later. It floated. It stuck things up and out of itself, pipes or wires. Then it moved around the lake and came in to the shore. A thing like a hatch opened and ... creatures got out of it. Not men!"

Lockley blinked again. "Look here—"

"Dammit, listen!" said Vale shrilly, "I'm telling you what I've seen. Things out of the sky. Creatures that aren't men. They landed and set up something on the shore. I don't know what it is. Do you understand? The thing is down there in the lake now. Floating. I can see it!"

Lockley swallowed. He couldn't believe this immediately. He knew nothing of radar reports or the seismograph record. He'd seen a barely balanced rock roll down the mountainside below him, and he'd heard a growling bass rumble behind the horizon, but things like that didn't add up to a conclusion like this! His first conviction was that Vale was out of his head.

"Listen," said Lockley carefully. "There's a short wave set over at the construction camp. They use it all the time for orders and reports and so on. You go there and report officially what you've seen. To the Park Service first, and then try to get a connection through to the Army."

Vale's voice came through again, at once raging and despairing, "They won't believe me. They'll think I'm a crackpot. You get the news to somebody who'll investigate. I see the thing, Lockley. I can see it now. At this instant. And Jill's over at the construction camp—"

Lockley was unreasonably relieved. If Jill was at the camp, at least she wasn't alone with a man gone out of his mind. The reaction was normal. Lockley had seen nothing out of the ordinary, so Vale's report seemed insane.

"Listen here!" panted Vale again. "The thing came down. There was a terrific explosion. It vanished. Nothing happened for a while. Then it came up and found a place where it could come to shore. Things came out of it. I can't describe them. They're motes even in my binoculars. But they aren't human! A lot of them came out. They began to land things. Equipment. They set it up. I don't know what it is. Some of them went exploring. I saw a puff of steam where something moved. Lockley?"

"I'm listening," said Lockley. "Go on!"

"Report this!" ordered Vale feverishly. "Get it to Military Information in Denver, or somewhere! The party of creatures that went off exploring hasn't come back. I'm watching. I'll report whatever I see. Get this to the government. This is real. I can't believe it, but I see it. Report it, quick!"

His voice stopped. Lockley painfully realigned the instrument again for Sattell, thirty miles to the southeast.

Sattell surprisingly answered the first call. He said in an astonished voice, "Hello! I just got a call from Survey. It seems that the Army knew there was a Survey team in here, and they called to say that radars had spotted something coming down from space, right after eight o'clock. They wanted to know if any of us supposedly sane observers noticed anything peculiar about that time."

Lockley's scalp crawled suddenly. Vale's report had disturbed him, but more for the man's sanity than anything else. But it could be true! And instantly he remembered that Jill was very near the place where frighteningly impossible things were happening.

"Vale just told me," said Lockley, his voice unsteady, "that he saw something come down. His story was so wild I didn't believe it. But you pass it on and say that Vale's watching it. He's waiting for instructions. He'll report everything he sees. I'm thirty miles from him, but he can see the thing that came down. Maybe the creatures in it can see him. Listen!"

He repeated just what Vale had told him. Somehow, telling it to someone else, it seemed at once even less real but more horrifying as a possible danger to Jill. It didn't strike him forcibly that other people were endangered, too.

When Sattell signed off to forward the report, Lockley found himself sweating a little. Something had come down out of space. The fact seemed to him dangerous and appalling. His mind revolted at the idea of non-human creatures who could build ships and travel through space, but radars had reported the arrival of a ship, and there were official inquiries that nearly matched Vale's account, which was therefore not a mere crackpot claim to have seen the incredible. Something had happened and more was likely to, and Jill was in the middle of it.

He swung the instrument back to Vale's position. His hands shook, though a part of his mind insisted obstinately that alarms were commonplace these days, and in common sense one had to treat them as false cries of "Wolf!" But one knew that some day the wolf might really come. Perhaps it had....

Lockley found it difficult to align the carrier beam to Vale's exact location. He assured himself that he was a fool to be afraid; that if disaster were to come it would be by the imbecilities of men rather than through creatures from beyond the stars. And therefore....

But there were other men at other places who felt less skepticism. The report from Vale went to the Military Information Center and thence to the Pentagon. Meanwhile the Information Center ordered a photo-reconnaissance plane to photograph Boulder Lake from aloft. In the Pentagon, hastily alerted staff officers began to draft orders to be issued if the report of two radars and one eye-witness should be further substantiated. There were such-and-such trucks available here, and such-and-such troops available there. Complicated paper work was involved in the organization of any movement of troops, but especially to carry out a plan not at all usual in the United States.

Everything, though, depended on what the reconnaissance plane photographs might show.

Lockley did not see the plane nor consciously hear it. There was the faintest of murmuring noises in the sky. It moved swiftly toward the north, tending eastward. The plane that made the noise was invisible. It flew above the cloud cover which still blotted out nearly all the blue overhead. It went on and on and presently died out beyond the mountains toward Boulder Lake.

Lockley tried to get Vale back, to tell him that radars had verified his report and that it would be acted on by the military. But though he called and called, there was no answer.

An agonizingly long time later the faint and disregarded sound of the plane swept back across the heavens. Lockley still did not notice it. He was too busy with his attempts to reach Vale again, and with grisly imaginings of what might be done by aliens from another world when they found the workmen near the lake—and Jill among them. He pictured alien monsters committing atrocities in what they might consider scientific examination of terrestrial fauna. But somehow even that was less horrible than the images that followed an assumption that the occupants of the spaceship might be men.

"Calling Vale ... Vale, come in!" He fiercely repeated the call into the instrument's microphone. "Lockley calling Vale! Come in, man! Come in!"

He flipped the switch and listened. And Vale's voice came.

"I'm here." The voice shook. "I've been trying to find where that exploring party went."

Lockley threw the speech switch and said sharply, "The Army asked Survey if any of us had seen anything come down from the sky. I gave Sattell your report to be forwarded. It's gone to the Pentagon now. Two radars reported tracking the thing down to a landing near you. Now listen! You go to the construction camp. Most likely they'll get orders to clear out, by short wave. But you go there! Make sure Jill's all right. See her to safety."

The switch once more. Vale's voice was desperate.

"A ... while ago a party of the creatures started away from the lake. An exploring party, I think. Once I saw a puff of steam as if they'd used a weapon. I'm afraid they may find the construction camp, and Jill...."

Lockley ground his teeth. Vale said unsteadily, "I ... can't find where they went.... A little while ago their ship backed out into the lake and sank. Deliberately! I don't know why. But there's a party of those ... creatures out exploring! I don't know what they'll do...."

Lockley said savagely, "Get to the camp and look after Jill! The workmen may have panicked. The Army'll know by this time what's happened. They'll send copters to get you out. They'll send help of some sort, somehow. But you look after Jill!"

Vale's voice changed.

"Wait. I heard something. Wait!"

Silence. Around Lockley there were the usual sounds of the wilderness. Insects made chirping noises. Birds called. There were those small whispering and rustling and high-pitched sounds which in the wild constitute stillness.

A scraping sound from the speaker. Vale's voice, frantic.

"That ... exploring party. It's here! They must have picked up our beams. They're looking for me. They've sighted me! They're coming...."

There was a crashing sound as if Vale had dropped the communicator. There were pantings, and the sound of blows, and gasped profanity—horror-filled profanity—in Vale's voice. Then something roared.

Lockley listened, his hands clenched in fury at his own helplessness. He thought he heard movements. Once he was sure he heard a sound like the unshod hoof of an animal on bare stone. Then, quite distinctly, he heard squeakings. He knew that someone or something had picked up Vale's communicator. More squeakings, somehow querulous. Then something pounded the communicator on the ground. There was a crash. Then silence.

Almost calmly Lockley swung his instrument around and lined it up for Sattell's post. He called in a steady voice until Sattell answered. He reported with meticulous care just what Vale had said, and what he'd heard after Vale stopped speaking—the roaring, the sound of blows and gasps, then the squeakings and the destruction of the instrument intended for the measurement of base lines for an accurate map of the Park.

Sattell grew agitated. At Lockley's insistence, he wrote down every word. Then he said nervously that orders had come from Survey. The Army wanted everybody out of the Boulder Lake area. Vale was to have been ordered out. The workmen were ordered out. Lockley was to get out of the area as soon as possible.

When Sattell signed off, Lockley switched off the communicator. He put it where it would be relatively safe from the weather. He abandoned his camping equipment. A mile downhill and four miles west there was a highway leading to Boulder Lake. When the Park was opened to the public it would be well used, but the last traffic he'd seen was the big trailer-truck of the Wild Life Control service. That huge vehicle had gone up to Boulder Lake the day before.

He made his way to the highway, following a footpath to the spot where he'd left his own car parked. He got into it and started the motor. He moved with a certain dogged deliberation. He knew, of course, that what he was going to do was useless. It was hopeless. It was possibly suicidal. But he went ahead.

He headed northward, pushing the little car to its top speed. This was not following his instructions. He wasn't leaving the Park area. He was heading for Boulder Lake. Jill was there and he would feel ashamed for all time if he acted like a sensible man and got to safety as he was ordered.

Miles along the highway, something occurred to him. The base line instrument had to be aimed exactly right for Vale or Sattell to pick up his voice as carried by its beam. Vale's or Sattell's instruments had to be aimed as accurately to convey their voices to him. Yet after the struggle he'd overheard, and after Vale had been either subdued or killed, someone or something seemed to have picked up the communicator, and Lockley had heard squeakings, and then he had heard the instrument smashed.

It was not easy to understand how the beam had been kept perfectly aligned while it was picked up and squeaked at. Still less was it understandable that it remained aimed just right so he could hear when it was flung down and crushed.

But somehow this oddity did not change his feelings. Jill could be in danger from creatures Vale said were not human. Lockley didn't wholly accept that non-human angle, but something was happening there and Jill was in the middle of it. So he went to see about it for the sake of his self-respect. And Jill. It was not reasonable behavior. It was emotional. He didn't stop to question what was believable and what wasn't. Lockley didn't even give any attention to the problem of how a microwave beam could stay pointed exactly right while the instrument that sent it was picked up, and squeaked at, and smashed. He gave that particular matter no thought at all.

He jammed down the accelerator of the car and headed for Boulder Lake.