Willy had spent two days, mostly off-duty time, visiting and working on the asteroid he had adopted, his two miles of irregular monstrosity. In his spurt of activity to install the drive unit, he had over-calculated a charge of explosives and blown out too much of the end section of the asteroid. That caused him some concern for a little while. In a flash of what he probably considered to be pure genius, he solved that minor problem by deciding to fill in the hole by installing a sub-space energizer. This first flash of genius was apparently followed by another inspirational flash. He could, with both installations, and some additional work, send the thing back to Earth. He must have been proud of the thought, for private satellites around Earth were all the rage now; no one who was Anyone was without one. Besides that, it would make a wonderful birthday present for his wife. Her birthday was only a matter of days away. * * * * * Goil's first request was to observe a day's operation. I had made what few arrangements were necessary, and Goil and I started out early so we could get into position and see the operations from the start. We had one of the observation flitters. I took it about twenty thousand miles out from the area of operations and parked with the forward port facing the area. I said: "We'll watch from here, Mr. Goil. You can see the debris floating down there." I pointed, and Goil looked at the little pin points of light reflecting from a great volume of dust, nebula-like in its dim luminosity. "When the crew starts actual operation, we will turn on the magnification screens and get some close-up views of the process." "Please explain this to me," said Goil. "I've never seen an asteroid's operation before." "Of course, Mr. Goil. I didn't know. This asteroid patch, or vein, as we like to call it, has a better than average content of metal ores and compounds. As you can see, we have swept the loose ends, so to speak, together. And there you see the result. In the center of that nebulous sort of mass is a large asteroid. There is at least one in almost every patch. We use that as the core, and by planting a large gravity generator on it and feeding it a great deal of power, it and the asteroid attracts most of the nearby debris. The gravity generator has been souped up tremendously. It burns out rather quickly, but it operates long enough for our purposes. There is a respectable layer of assorted sizes of asteroids hugging the core. And there are several miles of dust surrounding everything. After the gravity generator has burned out, the big attraction dies out, of course. But the proximity of the debris is still enough to hold them together for some time." [Illustration] "What is that stray body off to one side?" "That is the trigger asteroid," I answered.