When Larry Gibson returned to the ancient and seedy-looking _Sky Maid_ after a breakfast at a nearby restaurant, he paused to look at the work in progress outside her hull. It was like nothing that he had ever seen before. A network of interlacing wires was being bolted to the outside of the ship's cigar-shaped hull, so that they formed a sort of screen with the strands some two inches apart. Other men were busy at caulking rivets and repacking insulation. This last was routine stuff in connection with any attempt to recondition an old vessel for travel in the thin, chill regions of the strathosphere--but he was completely puzzled by the painstaking labor of fastening those criss-crossing wires in place. He found Ripon still in the vessel's dusty control room. Much of the equipment had been ripped out when the ship was first condemned. The missing articles had been hastily replaced with second-hand equipment which was often of a slightly different pattern from the original, so that the whole room had a makeshift appearance. The lean scientist looked up from the clouds of blue and vile-smelling smoke that swirled upward from his pipe. "Well, young feller!" he boomed in his deep voice that could easily carry above the dull roar of rocket motors. "How do you feel now? Ready to go to work?" "Listen!" Larry said. He had intended to be sharp and sarcastic, but he was grinning in spite of himself. It was hard to stay angry with anyone as irresponsibly cheerful as Crispin Gillingwater Ripon. "Seriously! You couldn't take the best rocket-ship on Earth to the Moon, let alone this old derelict. Not if you want to come back alive. It's been proven that, by the time you reach the velocity of escape to get away from the Earth's attraction, you have a speed too great for our present knowledge of rocket-ship technique to brake in time to prevent disaster...." "_How_ has that been proven?" Ripon interrupted, jerking the pipe from between his teeth and pointing the smoking stem at Larry as though it were the barrel of a ray-gun. "Why--by the two attempts that have been made! You know the story. Two hundred years ago, at the time we had the last war on Earth, that group of defeated outlaws stole the giant transport _Mercury_ and started for the Moon and vanished. Then, it was only thirty years ago that Professor Lester Staunton made his attempt in the rocket cruiser _Orestes_, and he vanished." "You're like all the rest," Ripon grumbled. "Always jumping to conclusions based on a few scraps of evidence. No man on Earth really knows how a rocket-ship would behave in interplanetary travel, because it hasn't yet been done. There is a great mass of unproven theories that are generally accepted as true--but those are not facts. It was once generally accepted that the Earth was flat. However--I have a new method of propulsion for this ship, by means of the amplification of magnetic currents, and I expect to supplement the rockets with that new equipment."