When Willy arrived to examine the shattered tug on the surface of the asteroid, he must have been pleasantly surprised to note that the hull was a battered mess, but miraculously some of the innards were intact. He must have looked closer and saw that the drive unit had escaped destruction. The drive unit of a tug is a super-heavy duty workhorse of a unit chock full of more power than would ever be packed or needed in a conventional ship of the same size. But as I said before, this was a propulsion unit from a tug, and tugs like ones we use need plenty of power. And that must have been when Willy decided on a reason for having his own private asteroid. He would add the drive unit to it and make it mobile. He must have sparkled with the idea for the rest of the day. I recall his accident report saying the tug was a total loss. Of course, no one checked Willy's decision on that. * * * * * I also had Willy under observation the time he retrieved the drive unit and took it to his newly acquired privately owned (now) asteroid. The peculiar shape of the asteroid would lend itself to adaptation to mobility. So Willy blasted off the tip of the elongated end with some explosives he had diverted from some other project, drilled it out with some small charges, and fitted the drive unit in it, and anchored it down. It had taken quite a while to do all that, but Willy had interminable patience once he started a project. The entire procedure would seem impossible for one man, but bulk and weight were no problems in space. And Willy constantly worked miracles. The question of what value a mobile asteroid would be among swarms of non-mobile asteroids way out in space where there was no place to go never seemed to have entered Willy's mind. (Now when I speak of "night" and "day," I speak of those periods of the twenty-four hour clock set forth as working and non-working periods. The working part was the "day" part of the twenty-four hours, during which we all engaged in our contracted occupations. The rest of the time until the twenty-four hour period ended was considered "night." Naturally, among the asteroids there was no rising and setting of the sun to help designate the passage of time. The reference to night and day is a habit which persists with space men no matter which part of the system they happen to be in.) A few days after Willy had finished installing the drive unit in his asteroid, a small company speedster came to a near-halt at the outer fringes of our section of the asteroid belt. For the next eighty hours it felt its way by radar through the belt, dodging and going around the larger bodies, and slowing its speed whenever it became necessary to shoulder its way through masses of smaller debris and dust. Finally it had our station in sight visually, and in a matter of hours later, it was edging its sleek sixty feet of length into a side gantry attached to the station.