"Like a hiring officer picking a starship crew, I have to look for guts, wits, and certain other qualities, in prospective helpers for what I am attempting. There may be danger. And I wouldn't want anyone to go soft and back out later. So here's your chance--part-time for the present. But I want a final yes or no." Mild Doc Lanvin could be hard. But he knew Jan's quality. She had taken courses of study and training, of which nine-tenths of the students were masculine. Her reactions to tests for quick thinking, emotional ruggedness, and physical stamina, were all good. Moreover, she had excelled in the study of instrument making, with which we had both occupied much time. Her manual precision was better than mine. "On your terms, count me in, Dr. Lanvin," she said quietly. "Even without Jan, I think I'd be a foregone conclusion, Doc," I told him. So, with every minute that we could spare from our regular studies, we were working with the great specialist of the miniature, trying to push another frontier downward into The Small. Doc had his duties to the University, but he had his nights and weekends, and the additional drive of the odd and grim reports which had already come from deep in space. Do you know what a micro-manipulator is? It begins with a simple, high powered microscope. But in its field of view are mounted little slide rods, fitted with hand operated vernier screws, by which they can make movements so fine that a gesture of a thousandth of a centimeter may seem the widest of swings. Attached to the slide rods are forceps, and measuring and cutting instruments, some too small to be visible to the unaided eye. Under one microscope Doc had even set up a real, power driven lathe, a quarter-inch long. Under another was a sort of assembly area. There, a shiny robot, half an inch high, with all the intricate control and circuits combined into it, was taking form. Cables were as fine as spiderwebs. III Reproducing that first robot in triplicate was easier than it might seem, for when we had set up all the small machinery to make the parts, duplication was almost automatic. But assembly remained a tedious chore. On the other hand, the control hoods were almost of the standard type used for much larger automatons. Still, it was eight months before Doc announced on a Saturday afternoon: "Step one completed. Now to repeat in step two!..." We had test proved all three robots as soon as each was ready. But now that each of us possessed a metal proxy, we could all go as a group on that first step down into The Small.