But beside the twin landing-stages, constructed by the World Federation, another building arose, with an open front. And that front was a huge mirror, now scintillating under the searchlight from the black ship. "That's it, Sir!" shouted Brent. "That's what?" snapped Nat. "The deflecting mirror I was speaking of. That's what deflected the ray that wiped out China. The ray didn't come from the Moon. And that's the mirror that deflects the teleradio waves, the super-Hertzian rays that carry the sound." Nat did not answer. Sick at heart at the failure of his mission, he was watching the swarm of Moon men who were at work upon the landing-stage, turning the steel clamps and regulating the mechanism that controlled the apparatus. Dwarfed, apish creature, with tiny limbs, and chests that stood out like barrels, they bustled about, chattering in shrill voices that seemed like the piping of birds. It was evident that Axelson, though he had wiped out the Moon convicts and the Moon people in the crater, had reserved a number of the latter for personal use. * * * * * The black ship was dropping into its position at the second landing-stage, connected with the first by a short bridge. The starboard hold swung open, and a file of shrouded and hooded forms appeared, masked men, breathing in condensed air from receptacles upon their chests, and staring with goggle eyes at their captives. Each one held in his hand a lethal tube containing the ray, and, as if by command, they took up their stations about their prisoners. Then, at a signal from their leader, they suddenly doffed their masks. Nat looked at them in astonishment. He had not known whether these would be Earth denizens or inhabitants of some other planet. But they were Earth men. And they were old. Men of sixty or seventy, years, with long, gray beards and wrinkled faces, and eyes that stared out from beneath penthouses of shaggy eyebrows. Faces on which were imprinted despair and hopelessness. Then the first man took off his mask and Nat saw a man of different character. A man in the prime of life, with a mass of jet black hair and a black beard that swept to his waist, a nose like a hawk's, and a pair of dark blue eyes that fixed themselves on Nat's with a look of Luciferian pride. "Welcome, Nathaniel Lee," said the man, in deep tones that had a curious accent which Nat could not place. "I ought to know your name, since your teleradios on Earth have been shouting it for three days past as that of the man who is to save Earth from the threat of destruction. And you know me!" "Axelson--the Black Caesar," Nat muttered. For the moment he was taken aback. He had anticipated any sort of person except this man, who stood, looked, and spoke like a Viking, this incarnation of pride and strength. Axelson smiled--and then his eyes lit upon Madge Dawes. And for a moment he stood as if petrified into a block of massive granite. "What--who is this?" he growled.