Didi Tang

Yingying Zhang, the daughter of a working-class factory driver from China, took the same career path as millions of other young Chinese academics before her: She traveled to a university in the U.S. with dreams of one day landing a professorship and being able to help her parents financially. But just weeks after arriving at the University of Illinois, the 26-year-old visiting scholar in agriculture sciences stepped off a bus on a sunny afternoon and got into black hatchback. She hasn’t been seen since.