The car went over a bridge and rounded a curve. Here a deep cut had been made and the road ran through it. It came out upon undulating ground where many curves were necessary.

Another car came, plunging after the others. In the next ten miles there were, perhaps a dozen more. They'd been hard to start, perhaps, and so left later than the rest. Jill wasn't in any of them. There was one car traveling slowly, making thumping noises. Its driver made the best time he could, following the others.

Sober common sense pointed out that Vale's account was fully verified. There'd been a landing of non-human creatures in a ship from outer space. The killing or capture of the first three men to investigate a gigantic explosion was natural enough—the alien occupants of a space ship would want to study the inhabitants of the world they'd landed on. The mere paralysis and release of two others could be explained on the theory that the creatures who'd come to earth were satisfied with three specimens of the local intelligent race to study. They had Vale, too. They weren't trying to conceal their arrival, though it would have been impossible anyhow. But it was plausible enough that they'd take measures to become informed about the world they'd landed on, and when they considered that they knew enough, they'd take the action they felt was desirable.

All of which was perfectly rational, but there was another possibility. The other possible explanation was—considering everything—more probable. And it seemed to offer even more appalling prospects.

He drove on. Jill Holmes. He'd seen her four times; she was engaged to Vale. It seemed extremely likely that she hadn't left the camp with the workmen. If Lockley hadn't been obsessed with her, he'd have tried to make sure she was left behind before he tried to find her. If she was still at the camp, she was in a dangerous situation.

There'd been no other car from the camp for a long way now. But there came a sharp curve ahead. Lockley drove into it. There was a roar, and a car came from the opposite direction, veering away from the road's edge. It sideswiped the little car Lockley drove. The smaller car bucked violently and spun crazily around. It went crashing into a clump of saplings and came to a stop with a smashed windshield and crumpled fenders, but the motor was still running. Lockley had braked by instinct.

The other car raced away without pausing.

Lockley sat still for a moment, stunned by the suddenness of the mishap. Then he raged. He got out of the car. Because of its small size, he thought he might be able to get it back on the road with saplings for levers. But the job would take hours, and he was irrationally convinced that Jill had been left behind in the construction camp.

He was perhaps five miles from Boulder Lake itself and about the same distance from the camp. It would take less time to go to the camp on foot than to try to get the car on the road. Time was of the essence, and whoever or whatever the occupants of the landed ship might be, they'd know what a road was for. They'd sight an intruder in a car on a road long before they'd detect a man on foot who was not on a highway and was taking some pains to pass unseen.

He started out, unarmed and on foot. He was headed for the near neighborhood of the thing Vale had described as coming from the sky. He was driven by fear for Jill. It seemed to him that his best pace was only a crawl and he desperately needed all the speed he could muster.