In half an hour the car stopped in front of a small building which looked something like a subway kiosk--except for the door, which, built of steel-reinforced lead, swung on a piano hinge having a pin a good eight inches in diameter. Laro opened that door. They went in. As the tremendously massive portal clanged shut, lights flashed on. Hilton glanced at his tell-tales, one inside, one outside, his suit. Both showed zero. Down twenty steps, another door. Twenty more; another. And a fourth. Hilton's inside meter still read zero. The outside one was beginning to climb. Into an elevator and straight down for what must have been four or five hundred feet. Another door. Hilton went through this final barrier gingerly, eyes nailed to his gauges. The outside needle was high in the red, almost against the pin, but the inside one still sat reassuringly on zero. He stared at the android. "How can any possible brain take so much of _this_ stuff without damage?" "It does not reach the brain, Master. We convert it. Each minute of this is what you would call a 'good, square meal'." "I see ... dimly. You can eat energy, or drink it, or soak it up through your skins. However it comes, it's all duck soup for you." "Yes, Master." Hilton glanced ahead, toward the far end of the immensely long, comparatively narrow, room. It was, purely and simply, an assembly line; and fully automated in operation. "You are replacing the Omans destroyed in the battle with the skeletons?" "Yes, Master." Hilton covered the first half of the line at a fast walk. He was not particularly interested in the fabrication of super-stainless-steel skeletons, nor in the installation and connection of atomic engines, converters and so on. He was more interested in the synthetic fluoro-silicon flesh, and paused long enough to get a general idea of its growth and application. He was very much interested in how such human-looking skin could act as both absorber and converter, but he could see nothing helpful. "An application, I suppose, of the same principle used in this radiation suit." "Yes, Master." * * * * * At the end of the line he stopped. A brain, in place and connected to millions of infinitely fine wire nerves, but not yet surrounded by a skull, was being educated. Scanners--multitudes of incomprehensibly complex machines--most of them were doing nothing, apparently; but such beams would have to be invisibly, microscopically fine. But a bare brain, in such a hot environment as this.... He looked down at his gauges. Both read zero. "Fields of force, Master," Laro said. "But, damn it, this suit itself would re-radiate ..." "The suit is self-decontaminating, Master." Hilton was appalled. "With such stuff as that, and the plastic shield besides, why all the depth and all that solid lead?" "The Masters' orders, Master. Machines can, and occasionally do, fail. So might, conceivably, the plastic."