The gimmick to fool him and cheat him. Where was it? Fenwick asked himself. Baker was sure it was here. If so, where could it be? There was no trickery in the crystal laboratory--unless it was the trickery of precision refinement of methods. Only men of great mechanical skill could accomplish what Ellerbee and his friend were doing. Genius behind the milking machine! Fenwick could almost sympathize with Baker in his hiding behind the ridiculous Index. Without some such protection a man could encounter shocks. The crackpot fringe. Where else would credence have been given to the phenomenon of a crystal that seemed to radiate in a nonelectromagnetic way? But, of course, it couldn't actually be doing that. All the books, all the authorities, and the known scientific principles said it couldn't happen. Therefore, it wouldn't have happened--outside the crackpot fringe. If Ellerbee and Atkins weren't trying to foist a deliberate deception, where were they mistaken? It was possible for such men as these to make an honest mistake. That would more than likely turn out to be the case here. But how could there be a mistake in the production of a phenomenon such as Fenwick had witnessed? How could that be produced through some error when it couldn't even be done by known electronic methods--not just as Fenwick had seen it. Throughout the morning Ellerbee led him down the rows of tanks, explaining at each step what was happening. Sometimes Sam Atkins offered a word of explanation also, but always he stayed in the background. The two farmers showed Fenwick how they measured crystal size down to the thickness of a molecule while the crystals were growing. A sudden suspicion crossed Fenwick's mind. "If those dimensions are so critical, how did you determine them in the first place?" "Initially, it was a lucky accident," said Sam Atkins. "Very lucky," said Fenwick, "if you were able to accidentally obtain a crystal of fifteen layers or so and have each layer even approximately correct." Sam smiled blandly. "Our first crystals were not so complex, you understand. Only three layers. We thought we were building transistors, then. Later, our mathematics showed us the advantage of additional layers and gave us the dimensions." The mathematics that Baker said a kid could poke holes in. Fenwick didn't know. He hadn't checked the math. Where was the gimmick? In the afternoon they took him out for field tests again. A rise behind the barn was about a mile from a similar rise on Sam Atkins' place. They communicated across that distance in all the ways, including various kinds of codes, that Fenwick could think of to find some evidence of hoax. Afterwards, they returned to the laboratory and sawed in two the crystals they had just used. Then they showed him the tests they had devised to determine the nature of the radiation between the crystals. He did not find the gimmick.