The more he contacted them the more he liked the little brown folk and the more he sympathized with their wish to get to the good green Earth. Essentially harmless, they were most admirable in their manner of living and considerate in their relations one to the other. Undoubtedly, New York had long since known of the absence of four important men from the Lunar workings. By now, quite likely, they had sent over one of the transports to learn what was wrong. But nothing could be done from there; they didn't even know of inner Luna. Bonwitt's nerves drew tautly near the breaking point. Peterson was waiting until the last minute to loose his supersonic vibrations on the unsuspecting brown folk. He'd have to wait till the moon had turned over and the beam of reflected sunlight was directed earthward. For the huge machines necessary to these important preliminaries needed many men in their operation. After that, these men could be dispensed with. One man could operate the final controls; one could blast out an entire city if he wished; one could operate the ethertype and make terms. Two were better; perhaps that was why Bonwitt was still alive. All too quickly came the day. Huge machines hummed and groaned. The great gelid sun began to roll slowly over the inner surface of the satellite. The outer shell of the moon started rotating. Luna was turning over. The great mirror of liquid metal above was revolving at precisely the speed to produce a plane surface, astronomically plane. Peel was at the final control with Peterson beside him, watching the viewing plate. Bonwitt was there, too. Peel's customary two guards.... The engineer hadn't had time to find the supersonic wave generator. How could Peterson get away to activate it? Bill's eyes dropped accidentally to the man's feet, one of which was edging toward the base of the control pedestal. A hidden button was there; this wholesale murder was to be accomplished by remote control! On the vision plate, Earth swung into view. The hitherto unseen side of the moon was facing it. What a furore must be upsetting both amateur and professional astronomers at home! Only a thin crescent was Earth now, with a vast dim area lighted only by moonlight from here. Soon there'd be a brilliant circle up there, a circle ten miles in diameter, sharp against the near-blackness. And, if Peterson won, it would close in gradually until there would be a searing, blazing speck consuming everything within its one mile circle. Not if Bonwitt could stop it. The super's foot, he saw, was nearing the secret button.