"They are basically very simple mechanical contrivances which are difficult in execution, but simple in concept. I will explain. Human thoughts, it was discovered after the Great Fire during the first glorious years of the City of New Hope, did not produce waves similar to radio waves, but the electrical synapse pattern, it was found, can be read by radio waves, in the same way a mine detector reads the existence of metal." "Radio?" Geo said. "That's right," Hama said. "Oh, I forgot, you don't know anything about that at all. Well, I can't go through the whole thing now. Suffice it to say that each of the jewels contains a carefully honed crystal which is constantly sending out beams which can read these thought patterns. Also the crystal acts like a magnifying glass or a mirror, and reflects and magnifies the energy from the brain into heat or light or any other kind of electromagnetic radiation--there I go again--so that you can send great bolts of heat with them, as you have seen done. "But the actual workings of them are not important. And their ability to send heat out is only their secondary power. Their primary importance is that they can be used to penetrate the mind. Now we come to the lizards." "Wait a minute," Geo said. "Before we get to the lizards. Do you mean go into minds like Snake does?" Suddenly he remembered that the boy was not there. But the god went on. "Like Snake," he said. "But different. Snake was born with the ability to transmute the brain patterns of his thoughts to others; in that he has a power something like the jewels, but nowhere as strong. But with the jewels, you can jam a person's thoughts...." "Just go into his mind and stop him from thinking?" asked Iimmi. "No," said the god. "Conscious thought is too powerful. Otherwise, you would stop thinking every time Snake spoke to you. It works another way. How many reasons does a man have for any single action?" They looked at him uncomprehendingly. "Why, for example, does a man pull his hand from a fire?" "Because it hurts," said Urson. "Why else?" "Yes, why else?" asked Hama. "I think I see what you mean," said Iimmi. "He also pulls it out because he knows that outside the fire his hand isn't going to hurt. Like the bird, I mean the lizard. One reason we reacted like we did was because it sounded like a bird. The other reason was because we wanted to hear a bird just then. The man pulls his hand out because the fire hurts, and because he wants it not to hurt." "In other words," Geo summarized, "there are at least two reasons for everything." "Exactly," explained Hama. "And notice that one of these reasons is unconscious. But with the jewel, you can jam the unconscious reason; so that if a man has his hand in a fire, you can jam his unconscious reason of wanting it to stop hurting. Completely bewildered, and in no less pain, he will stand there until his wrist is a smoking nub." Geo reached over and felt his severed arm.