Lockley noted that the human confederates of the monsters had no protection against the beam to match his own. Perhaps the monsters themselves were protected only near the projectors. This was an item affecting his plans of revenge for Jill. He stored it away in his mind. Then he realized that the weapons in the car had exploded just like the pistol on his own seat cushion. The explosion was not associated with the terror beam. There'd been no beam in action when his own pistol blew up. It did not seem reasonable that if the monsters possessed a detonation beam that they'd turn it on their own confederates.
No. Rational beings would do nothing so self-contradictory.
Then Lockley looked down at the cheese grater-pocket radio device of his own manufacture. He considered the fact that his own pistol had exploded the instant he'd turned the gadget on. The weapons in the other car detonated when that car was near him.
He plodded onward thinking very clearly and precisely about the matter. He even remembered to turn off his gadget because he would need it to avenge Jill. But when he tried to think of any subject unconnected with revenge, his mind became confused and agitated.
Two miles along the highway, which had not yet turned to head in toward Boulder Lake, there was a farmhouse. Lockley walked heavily to the abandoned building. He found the door locked. Without conscious thought, he forced it. He searched the closets. He found a shotgun and half a box of shells. He considered them, then left the gun and all the shells but three. He went out. Presently he laid a shotgun shell down on the road. He paced off twenty-five yards and dropped another. He dropped a third twenty-five yards farther on, and then carefully counted off three hundred feet. The car had been just about that far away when the explosions came.
He turned on his device. Two of the three shells exploded smokily. The farthest away did not explode.
He did not rejoice. He went on without elation, but it became a part of his painstaking search for vengeance that he knew he could set off explosives within a hundred and twenty-five yards of himself. There was something about the device he'd constructed which made explosives detonate, up to a distance of a little over one hundred yards. He felt no curiosity about it, though it was simple enough. The heterodyning of extremely saw-toothed waves produced peaks of energy until the saw-teeth began to smooth out. There were infinitesimal spots in which, for infinitesimal lengths of time, energy conditions comparable to sparks existed. This had not been worked out in advance, but the reason was clear.
He came to the place where the main highway to Boulder Lake branched off from the road he was following. He turned into it, walking doggedly.
Three miles toward the lake, an engine sounded from behind him. He got off the highway and turned the switch. A half-ton truck came trundling openly along the road. It came closer and closer.
Small-arm ammunition exploded. The engine stopped and the light truck toppled over onto its side. Lockley did not approach it. Its driver might not be dead, and he would not find it possible to leave any man alive who was associated with Jill's captors. He passed the truck and went on up the highway.