"I think I can handle her myself, now. Thanks very much," Edwards said, and Holden departed to do a little investigating on his own. * * * * * In the tube-room at the stern, he found Linet. The doughty Captain had evidently been giving the men a thorough raking over, for they were all looking slightly sheepish, as men do when they have had to reveal the most intimate details of their lives. "All in shape here," Linet reported. "Five of the men I know best are searching the living quarters, under command of Professor Erickson. If you will come with me now, we will go to the observation room, where the rest of the men are loafing while off duty." As they passed down the central hall in the section where the cabins were located, a man ran out from a side passage, saw them, and turned at full speed for the bow. "Stop him," came a shout. Holden recognized the voice as Erickson's. The man heard it, too, for he whirled in his tracks, whipped an old-fashioned automatic pistol from his pocket, leveled it at Holden, and took careful aim. The fraction of a second during which his eye rested along the sights was his undoing. Captain Linet's hand, hidden under the loose jacket he was wearing, pressed the release on his short-range ray pistol, a light bluish streak touched the man's breast, and he fell forward, his heart literally shattered by the energy of the ray. Holden reached him first, and rolled him over. His face was faintly familiar, and doubt changed to recognition as Captain Linet exclaimed, "It's Chambers, a former petty officer on my airliner." It was the man who had come up to the Captain while Holden and Erickson were conversing with him on the bridge. "What on earth could the man have been up to? He must have been mad to attack me on this ship, with no chance of escape," exclaimed Holden. "Do you know anything of his record, Captain?" "Nothing whatsoever, except that he seemed honest enough, and hard working. I was the one responsible for his presence on board here, as he had mentioned some knowledge of interplanetary travel, and we needed men." Erickson had come up by that time. "We found nothing in this man's cabin except some tools that he had evidently stolen from the machine shop, and a code book of the type used by commercial companies for interplanetary messages. He entered the room while we were searching it, and bolted when he saw us." The thing was puzzling, but most of the men on board accepted the explanation that the man was mad, and had for some reason resorted to desperate measures to assure the safety of the moon. "You know," explained Captain Linet, "back a few hundred years ago, there was the expression 'moonstruck' applied to people who were mentally deranged."