Lee returned to his desk. He sat down and stared at Childe's graph again. After a few minutes, he angrily slapped it in a drawer, slammed the thing shut, and stamped out of the room. * * * * * Personal matters were soon buried in the excitement of another discovery, this time an important one. It looked promising. Kurtzman and Kulaki finally discovered what form of energy the antennas were beaming out. After years of trial-and-error experimentation, the engineer and electronicist asked Richards and Childe to lend a hand. With a firm theoretical and mathematical background to bolster their work, Kurtzman and Kulaki started out on a process of elimination. They soon proved that the antennas were not broadcasting any known form of electromagnetic energy, from gamma to long-radio waves. They investigated one possibility after another, turning up a steady succession of negative answers. Negative, but answers all the same. It was time-consuming, but at least they were definitely determining which avenues were blind alleys. Then Childe started tinkering with a hunch, and showed his paperwork to Richards. The two of them made a few suggestions to Kurtzman and Kulaki. Their problem was that their detection instruments were drawing blanks, when applied to the antennas' output. But the power input to the antennas showed they were working continuously. Childe showed, mathematically, that their output must be an extremely weak, low-frequency form of energy. Richards agreed, and pointed out that there was only one known form of energy that fulfilled these conditions: gravity. "Gravity waves?" Kurtzman asked, incredulously, when they told him about it. Kulaki's mind reacted faster. "Knowing it's gravity waves, on paper, and proving it experimentally are two different things." But they were up to the test. They had to scavenge equipment from the center's grav screen machinery, and the whole underground community was without its Earth-normal grav field for two and a half days, but when the field was returned to normal (and people stopped hopping and bouncing all through the center) Kurtzman and Kulaki had proved that the antennas were indeed beaming out gravity waves. _It's all here_, Lee thought, as he read their combined report. _Now we know what the machine is doing. But to what purpose? What influence does this have on Earth?_ Then he put down the report and turned to another bit of paperwork that lay on his desk: Elaine's official request for a transfer. He looked through it automatically. There was a place marked _Justification for Request_. Elaine had typed simply, "Personal." Lee flipped to the last page and signed. He leaned back in his chair and tried to let his mind float free; forget about her, forget about the buildings out there, forget about everything ... at least for a few moments. Just drift and let your mind wander where it pleases.... * * * * *