They had grown themselves into the rock; wormed their way in with soft-bodied relentless persistence. ESAIRS was riddled with tunnels; their sharp-toothed tunneling hoops ran around the clock. They had air blowers rigged from vinyl sacks and ribs of memory plastic. The ribs breathed . They were wired to the tokamak fusion plant, and a small change in voltage made them bend and flex, bend and flex, sucking in air with a pop of plastic lung and an animal wheeze of exhalation. It was the sound of life inside the rock, the rasp of the hoops, the blowers breathing, the sullen gurgling of the fermenters.