"There is an extensive underlying layer of gypsum, here," he said. "The water-bearing rock. A mile away there's an ample deposit of graphite--carbon. Thus, there exists a complete local source of hydrogen, oxygen and carbon, ideal for synthesizing various hydrocarbonic chemicals or making complicated polyethylene materials such as stellene, so useful in space. Lead, too, is not very far off. Silicon is, of course, available everywhere. There'll be a plant belonging to Hoffman Chemicals here, before too long. I was prospecting for them, for a site like this. Actually I was very lucky, locating this spot almost right away--which is fortunate. They think I'm still looking, and aren't concerned..." Rodan was quiet for a moment before continuing. The pupils of his eyes dilated and contracted strangely. "Because I found something else," he went on. "It was luck beyond dreams, and it must be my very own. I intend to investigate it thoroughly, even if it takes years! Come along, again!" This time the walk was about three hundred yards, past three small stellene domes, the parabolic mirrors of a solar-power plant, a sun-energized tractor, and onward almost to the mountain wall, imbedded in the dust of the mare. There Frank noticed a circular, glassy area. Strips of magnesium were laid like bridging planks across chunks of lava, and in the dust all around were countless curious scrabbled marks. Rodan stood carefully on a magnesium strip, and looked back at Nelsen and Lester, his brows crinkling as if he was suspicious that he had already told them too much. Frank Nelsen became more aware of the heavy automatic pistol at Rodan's hip, and felt a tingling urge to get away from here and from this man--as if a vast mistake had been made. "It is necessary for you to be informed about _some_ matters," Rodan said slowly. "For instance, unless it is otherwise disturbed, a footprint, or the like, will endure for millions of years on the Moon--as surely as if impressed in granite--because there is no weather left to rub it out. You will be working here. I am preserving some of these markings. So please walk on these strips, which Dutch and I have laid down." Rodan indicated a large, Archer-clad man, who also carried an automatic. He had the face of a playful but dangerous mastiff. He was hunkered down in a shallow pit, scanning the ground with a watch-sized device probably intended for locating objects hidden just beneath the surface, electronically. Beside him was a screen-bottomed container, no doubt meant for sifting dust. "Greetings, Novices!" he gruffed with genial contempt. But his pale eyes, beyond the curve of his helmet, had a masked puzzlement, as if something from the lunar desolation had gotten into his brain, leaving the realization of where he was, permanently not altogether clear to him. Rodan pulled a shiny object from his thigh pouch, and held it out in a gloved palm for his new employees to peer at.