They drive south for two days to Xi'an, the ultimate destination Lake Ching, a large fresh water lake two hours west of Xi'an, where the authorities have a special assignment for him that "no one else wants" but which piques his own interest, partly because it may help restore his former status: the massacre of a boat-full of seventeen foreign scientists and businessmen months earlier and the more recent disappearance of the original investigator assigned to the case.