“I was abducted because I was raising uncomfortable questions with my art,” the Chinese-born Ai Weiwei wrote a few years ago in an Op-Ed for The New York Times. Once a political prisoner, Ai’s rebellious spirit remains intact. In his latest conceptual work, which includes a haunting documentary film set in 2020, in Wuhan, Ai looks at democracy, surveillance, and censorship, and delves into issues of human rights. —E.C.