He drove on. The highway turnoff to Tenochitlan appeared. Calhoun went steadily past it. The other connection with the road through the town appeared. He left it behind. Allison's teeth chattered again. The buildings of Maya City began to appear, some twenty minutes later. Calhoun slowed and the other cars closed up. He opened a window and called: "We want to go to the landing-grid first. Somebody lead the way!" A car went past and guided the rest assuredly to a ramp down from the now-elevated road, and through utterly dark streets, of which some were narrow and winding, and came out abruptly where the landing-grid rose skyward. At the bottom its massive girders looked huge and cyclopean in the starlight, but the higher courses looked like silver lace against the stars. * * * * * They went to the control building. Calhoun got out. Murgatroyd hopped out after him, dust clinging to his fur. He shook himself, and a ten-thousand-credit interstellar credit certificate fell to the ground. Murgatroyd had made a soft place for sleeping out of the contents of Allison's attache case. It was assuredly the most expensive if not the most comfortable sleeping cushion a _tormal_ ever had. Allison sat still as if numbed. He did not even pick up the certificate. "I need you two electronics men," said Calhoun. Then he said apologetically to the others, "I only figured out something on the way here. I'd believed we might have to take some drastic action, come daybreak. But now I doubt it. I do suggest, though, that you turn off the car headlights and get set to do some shooting if anybody turns up. I don't know whether they will or not." He led the way inside. He turned on lights. He went to the place where dials showed the amount of power actually being used of the enormous amount available. Those dials now showed an extremely small power drain, considering that the cities of a planet depended on the grid. But the cities were dark and empty of people. The demand needle wavered back and forth, rhythmically. Every two seconds the demand for power went up by six million kilowatts, approximately. The demand lasted for half a second, and stopped. For a second and a half the power in use was reduced by six million kilowatts. During this period only automatic pumps and ventilators and freezing equipment drew on the broadcast power for energy. Then the six-million-kilowatt demand came again for half a second. "The cattle fence," said Calhoun, "works for half a second out of every two seconds. It's intermittent or it would simply paralyze animals that wandered into it. Or people. Being intermittent, it drives them out instead. There'll be tools and parts for equipment here, in case something needs repair. I want you to make something new." The two electronics technicians asked questions.