"But this thought, 'Dilipic'?" Garlock asked, impatiently. "It is merely a symbol—it doesn't mean anything—to me, at least. What are they? Where do they come from?"

"No one knows anything about them," came the surprising answer. "Not even their physical shape—if they have any. Nor where they come from, or how they do what they do."

"They can't be very common," Garlock pondered. "We have never heard of them before."

"Fortunately, they are not," the Inspector agreed. "Scarcely one world in five hundred is ever attacked by them—this is the first Dilipic invasion I have seen."

"Oh, you Arpalones don't die with your worlds, then?" Lola asked. She was badly shaken. "But I suppose the Arpales do, of course."

"Practically all of the Arpales will die, of course. Most of us Arpalones will also die, in the battles now going on. Those of us who survive, however, will stay aloft until the rehabilitation fleet arrives, then we will continue our regular work."

"Rehab?" Belle exclaimed. "You mean you can restore planets so badly ruined that all the people die?"

"Oh, yes. It is a long and difficult work, but the planet is always re-peopled."

"Let's go down," Garlock said. "I want to get all of this on tape."

They went down, over what had been one of that world's largest cities. The air, the stratosphere, and all nearby space were full of battling vessels of all shapes and sizes; ranging from the tremendous globular spaceships of the invaders down to the tiny, one-man jet-fighters of the Arpalones.