The control at Canaveral did not answer the next message, nor was there any response when they tried the emergency frequencies. They picked up some aircraft chatter on the higher frequencies, but no one noticed them or paid any attention to their repeated calls. They looked at the blue sphere of Earth, with horror now, and only after an hour of sweating strain would they admit that, for some unimaginable reason, they were cut off from all radio contact with it.
"Whatever happened, happened during our last orbit around the moon. I was in contact with them while you were matching orbits," Dan said, tapping the dial of the ammeter on the radio. "There couldn't be anything wrong...?"
"Not at this end," Gino said grimly. "But something has happened down there."
"Could it be ... a war?"
"It might be. But with whom and why? There's nothing unusual on the emergency frequencies and I don't think...."
"Look!" Dan shouted hoarsely, "The lights—where are the lights?"
In their last orbit the twinkling lights of the American cities had been seen clearly through their telescope. The entire continent was now black.
"Wait, see South America—the cities are lit up there, Gino. What could possibly have happened at home while we were in that orbit?"
"There's only one way to find out. We're going back. With or without any help from ground control."
They disconnected the lunar Bug and strapped into their acceleration couches in the command module while they fed data to the computer. Following its instructions they jockeyed the Apollo into the correct attitude for firing. Once more they orbited the airless satellite and at the correct instant the computer triggered the engines in the attached service module. They were heading home.