"We'd better be careful," Bill said doubtfully. "They're more likely to surprise us. If you had been in front of one of those little purple bombs, flying on the white ray!"
"We have a sort of rocket torpedo that Doc Trainor invented. The Prince means to try that on 'em."
The Red Rover dropped swiftly, with Smith's skilled hands on the controls. It seemed but a few minutes until the dark shadow of the earth beneath abruptly resolved itself into a level plain scattered with looming shapes that were clumps of mesquite and sagebrush. The slim silver cylinder came silently to rest upon the desert, beneath stars that shone clearly, though to Bill they seemed dim in comparison with the splendid wonders of space.
Three hours before dawn, five men slipped out through the air-lock. The Prince himself was the leader, with Captains Brand and Smith, Bill, and a young officer named Walker. Each man carried a searchlight and a positive ray pistol. And strapped upon the back of each was a rocket torpedo—a smooth, white metal tube, four feet long and as many inches thick, weighing some eighty pounds.
Dr. Trainor, kindly, bald-headed old scientist, was left in charge of the ship. He and his daughter came out of the air-lock into the darkness, to bid the five adventurers farewell.
"We should be back by night," said the Prince, his even white teeth flashing in the darkness. "Wait for us until then. If we don't come, return at once to the City of Space. I want no one to follow us, and no attempt made to rescue us if we don't come back. If we aren't back by tomorrow night we shall be dead."
"Very good, sir," Trainor nodded.
"I'm coming with you, then," Paula declared suddenly.
"Absolutely you are not!" cried the Prince. "Dr. Trainor, I command you not to let your daughter off the ship until we return."
Paula turned quickly away, a slim pillar of misty white in the darkness. Bill heard a little choking sound; he knew that she had burst into tears.