In the midst of a curving room hung and inset with a thousand shining gadgets, Pyotr Diavilev floated in the air. A black-browed man took his arm carefully and pulled him to the floor, placed magnetic-soled shoes on his feet. Diavilev could not help grinning delightedly. The dark man, whose name was Krylov, stood thoughtfully and absently scratching his cheek. "Now as to why you are here," he said, and Diavilev tensed and waited. There were three other men in the room, but no one moved. "You understand of course what this station is, and that the building of it places us, our people, in control of the world." Diavilev nodded. "Atomic missiles launched from this base may be guided exactly to any point on the surface of the Earth that we select, yet the station itself represents so small and distinct a target as to be virtually invulnerable. Russia, my friend, need fear no country on Earth. Not," he added quickly, "that she ever did, of course." Diavilev, with the inbred habit of years, gave his congratulations. Krylov stood looking at him closely, half-smiling, rubbing again at his cheek. There was something infinitely chilling in the moment, but Diavilev was able to smile back. "This station has been in existence," said Krylov, "for slightly more than a week. There are not fifty people in the entire world who know of it. You have become one. You are therefore most important." Diavilev was becoming nervous. "But you are important," Krylov went on slowly, "for other reasons. To be exact, you are perhaps as important at this moment as any man who ever lived." Diavilev, dazed, struggled to digest that while Krylov held him with his eyes and the three other men spoke lowly among themselves. "I am saying all this to impress upon you the vastness of the work with which you have been entrusted. I want you to understand clearly that the accuracy of your work could mean the collapse of all our enemies, of the entire capitalistic empire. Therefore you _will_ be accurate." There was a fixity to Krylov's face which was unsettling. Diavilev waited, uneasy and bewildered. The dark man smiled. "You are a Russian," he stated powerfully. "We know that you will do your best." "Of course," Diavilev said. Krylov turned and pulled open a drawer. Out of the drawer he drew a chart and handed it to Diavilev. "Do you recognize that?" Diavilev stared. "That is the plotted orbit," Krylov said carefully, "of a moon. It is not of course the moon with which you are familiar. But it is a moon circling the Earth, a _second_ moon. "It is a moon of which no one knows, excepting ourselves and the Kremlin. We discovered it shortly after we arrived, when it passed quite near the station. It is small and dark, too small and non-reflecting to be seen from Earth. It is approximately five miles wide. "Do you understand?" Diavilev who had had to digest a great many things in a very short while, was able to nod. Because this was, after all, Diavilev's field.