He searched the photograph which was so much more detailed than a map. There were mountains to the north of Maya City, but only one highway led north. There were more mountains to the west. One highway went into them, but not through. To the south there was sea, which curved around some three hundred miles from Maya City and put the human colony on Maya on a peninsula.
"They went east," said Calhoun presently. He traced lines with his finger. "Three highways go east; that's the only way they could go quickly. They hadn't been sure they'd have to go but they knew where to go when they did. So when they got their warning, they left. On three highways, to the east. And we'll follow them and ask what the hell they ran away from. Nothing's visible here!"
He went back to the Med Ship, Murgatroyd skipping with him.
As the airlock door closed behind them, he heard a click from the outside-microphone speakers. He listened. It was a doubled clicking, as of something turned on and almost at once turned off again. There was a two-second cycle, the same as that of the power drain. Something drawing six million kilowatts went on and immediately off again every two seconds. It made a sound in speakers linked to outside microphones, but it didn't make a noise in the air. The microphone clicks were induction; pick-up; like cross-talk on defective telephone cables.
Calhoun shrugged his shoulders almost up to his ears. He went to the communicator.
"Calling Candida—" he began, and the answer almost leaped down his throat.
"Candida to Med Ship. Come in! Come in! What's happened down there?"
"The city's deserted without any sign of panic," said Calhoun, "and there's power and nothing seems to be broken down. But it's as if somebody had said, 'Everybody clear out' and they did. That doesn't happen on a whim! What's your next port of call?"
The Candida's voice told him, hopefully.