They had penetrated a long way into the factory. The final level lap spread out ahead of them. O’Neill flashed the light here and there, trying to locate undestroyed sections, portions of the assembly process still intact.

It was Morrison who felt it first. He suddenly dropped to his hands and knees; heavy body pressed against the floor, he lay listening, face hard, eyes wide. “For God’s sake—”

“What is it?” O’Neill cried. Then he, too, felt it. Beneath them, a faint, insistent vibration hummed through the floor, a steady hum of activity. They had been wrong; the hawk had not been totally successful. Below, in a deeper level, the factory was still alive. Closed, limited operations still went on.

“On its own,” O’Neill muttered, searching for an extension of the descent lift. “Autonomous activity, set to continue after the rest is gone. How do we get down?”

The descent lift was broken off, sealed by a thick section of metal. The still-living layer beneath their feet was completely cut off; there was no entrance.

Racing back the way they had come, O’Neill reached the surface and hailed the first truck. “Where the hell’s the torch? Give it here!”

The precious blowtorch was passed to him and he hurried back, puffing, into the depths of the ruined factory where Morrison waited. Together, the two of them began frantically cutting through the warped metal flooring, burning apart the sealed layers of protective mesh.

“It’s coming,” Morrison gasped, squinting in the glare of the torch. The plate fell with a clang, disappearing into the level below. A blaze of white light burst up around them and the two men leaped back.

In the sealed chamber, furious activity boomed and echoed, a steady process of moving belts, whirring machine-tools, fast-moving mechanical supervisors. At one end, a steady flow of raw materials entered the line; at the far end, the final product was whipped off, inspected and crammed into a conveyer tube.