The bare steel and scabrous epoxy ended abruptly, replaced by what Case at first took to be a rough tunnel blasted from solid rock. Molly examined its edge and he saw that in fact the steel was sheathed with panels of something that looked and felt like cold stone. She knelt and touched the dark sand spread across the floor of the imitation tunnel. It felt like sand, cool and dry, but when she drew her finger through it, it closed like a fluid, leaving the surface undisturbed. A dozen meters ahead, the tunnel curved. Harsh yellow light threw hard shadows on the seamed pseudo-rock of the walls. With a start, Case realized that the gravity here was near earth normal, which meant that she’d had to descend again, after the climb. He was thoroughly lost now; spatial disorientation held a peculiar horror for cowboys.