On a vast, dry lakebed called Tianshuihai, we came to a community of sorts, a desperate huddle of concrete and mud structures. My map labeled the region “Soda Plain,” and it seemed a long time since any water had gathered there. It was also, evidently, earthquake country. Buildings, many of them abandoned, had been shaken off their foundations; their walls had cracked and roofs fallen in. The military post and gas depot where Qu stopped to refuel had been shored up by heavy concrete buttresses. Thousands of fifty-gallon drums littered the ground, along with broken machinery, derelict vehicles, chunks of concrete, goat carcasses, cans, bottles, and shit.