Allison's mouth dropped open. Extreme suspicion and unease appeared on his face. As a sign of the unease, his hand went to the side coat pocket in which he'd put a blaster. He didn't pluck it out. Calhoun's left fist swung around and landed. He took Allison's elaborate pocket blaster and threw it away among the monotonous rows of olive-green plants. He returned to absorbed observation of Murgatroyd. In five minutes the muscular spasms diminished. In ten, Murgatroyd frisked. But he seemed to think that Calhoun had done something remarkable. In the warmest of tones he said: "_Chee!_" "Very good," said Calhoun. "We'll go ahead. I suspect you'll do as well as we do--for a while." The car lifted the few inches the air columns sustained it above the ground. It went on, still to the eastward. But Calhoun drove more slowly now. "Something was giving Murgatroyd rhythmic muscular spasms," he said coldly. "I gave him medication to stop them. He's more sensitive than we are, so he reacted to a stimulus we haven't noticed yet. But I think we'll notice it presently." Allison seemed to be dazed at the affront given him. It appeared to be unthinkable that anybody might lay hands on him. "What the devil has that to do with me?" he demanded angrily. "And what did you hit me for? You're going to pay for this!" "Until I do," Calhoun told him, "you'll be quiet. And it does have the devil to do with you. There was a Med Service gadget once--a tricky little device to produce contraction of chosen muscles. It was useful for re-starting stopped hearts without the need of an operation. It regulated the beat of hearts that were too slow or dangerously irregular. But some businessman had a bright idea and got a tame researcher to link that gadget to ground induction currents. I suspect you know that businessman!" "I don't know what you're talking about," snapped Allison. But he was singularly tense. "I do," said Calhoun unpleasantly. "I made a public health inspection on Texia a couple of years ago. The whole planet is a single, gigantic, cattle-raising enterprise. They don't use metal fences--the herds are too big to be stopped by such things. They don't use cowboys--they cost money. On Texia they use ground-induction and the Med Service gadget linked together to serve as cattle fences. They act like fences, though they're projected through the ground. Cattle become uncomfortable when they try to cross them. So they draw back. So men control them. They move them from place to place by changing the cattle fences, which are currents induced in the ground. The cattle have to keep moving or be punished by the moving fence. They're even driven into the slaughterhouse chutes by ground-induction fields! That's the trick on Texia, where induction fields herd cattle. I think it's the trick on Maya, where people are herded like cattle and driven out of their cities so the value of their fields and factories will drop,--so a land buyer can find bargains!"