It was more or less as Chet had predicted. The chamber at the end of this adit contained a surprisingly large machine that must have been brought down in pieces and assembled here. Its most prominent feature was a giant, rusty wheel with cables running over grooves in its rim and descending into the hole below. Obviously the thing hadn’t moved in eons and so Zula, had she been a recreational spelunker, would have given up and turned around at this point. But Chet insisted, and more Day-Glo-green graffiti affirmed, that there was a way down. She followed him around to the back side of the machine. She began to collect that the shaft below them was circular in cross section, but that the circle had been parceled out into a bundle of separate squarish or rectangular passageways. The largest of these was in the middle and was serviced by the giant wheel, but smaller ones seemed to be reserved for other purposes such as cabling, ventilation, dumbwaiter-like rigs for carrying ore, and the ladder that could be used when nothing else was functioning. Chet gave the top of this a good careful look, inspecting for booby traps. Then he undid his belt, threaded it through the wrist loop on his flashlight, and rebuckled it so that the light would dangle in front of his crotch and the beam would shine downward. He began to descend the ladder with such speed that Zula feared he was falling, rather than climbing. She got the sense that he just wanted to get this over with. Perhaps he was expecting to find a booby trap at the bottom and wanted to set it off long before she got there. This didn’t give her a lot of incentive to move quickly. Gripping her flashlight in one fist so that it shone downward, she began to descend the ladder, and quickly found herself in an environment that would have been violently claustrophobic had she been disposed to such feelings. Space in the shaft was apparently precious and the engineers didn’t want to sacrifice any more than was absolutely necessary to this purpose. Her pack kept getting wedged against the wall behind her, or hung up on brackets, forcing her to push back a little wave of panic each time.