On a Sunday night our ship blasted off from the New Mexico desert. When our acceleration was completed, our ringlike hull began to rotate, to give us a centrifugal substitute for gravity. The outer silence closed in, and two months of monotonous journeying provided only a new setting for our efforts to build us metal forms that could stand beside an inscription on a sand-grain meteor as a man stands beside a monument. All of Doc's home workshop had been transferred to the _Intruder_. There, in the lab compartment, Doc, Jan and I sat hour after hour, wearing our control hoods, but living in metal bodies half an inch high that bent intently over an even far finer and more difficult craftsmanship. We passed Mars' orbit without seeing the new man-made airdome cities among the ruins. We saw nothing of the asteroid belt where fortunes were being made in metals from the heavy core of an exploded planet. Our quest had a different goal. When we finished three super-micro-manipulators, we were better prepared to finish our tools and equipment to make parts. But our tedious job was less than half done when we arrived on Ganymede, cold and bleak, its tenuous atmosphere composed mostly of unbreathable methane gas. Scharber brought us down on the landing stage of Port Hoverton. The settlement itself was under domes nearby. And Jan said: "Hurdy-gurdies, Charlie! Hey, Doc! Scharber! Bow! Beer, music, games. A last fling, like the spacemen and miners! Let's have it!" So we did for a few hours. Then we had us a good sleep. Then we found a guide. Boom Harlow, he called himself. Oldish, cheerful as a gravedigger. "Sure I'll take you to where that little tool chest was found," he said. "If you stay, likely you'll never come back." He blasted off with us for a thousand-mile jaunt in our ship, arcing above the stratified mists of half-congealed gases that hovered over the Ganymedean landscape, and after we had landed at his command, he pointed out stone structures that looked both very old and very odd. "There you are!" he said through the helmet phones of our space suits. "Maybe the last camp of the last survivors of Planet X, came here millions of years ago, before their world went ffttt--before there were asteroids. But there's something here yet, I'm tellin' yuh! Now, after you pay me, I'll get my mono-wing out of your hold, and fly back to town, and I hope I won't stop long before I rocket back to Seattle. Keep alive if you can. So long." Boom Harlow was gone, then, riding a jetted metal triangle high against the thin murk. The rest of us were left with the creeps and the wonder, and all the work we had to do. * * * * *