Compelling and provocative documentary, “Ai Weiwei: Never Sorry,” an enlightening portrait on the internationally renowned Chinese artist and activist and unprecedented inside look at Chinese politics. In April 2011, when Ai disappeared into police custody for three months, he quickly became China’s most famous missing person, having first risen to international prominence in 2008 after helping design Beijing’s iconic Bird’s Nest Olympic Stadium and then publicly denouncing the Games as party propaganda. Since then, Ai Weiwei’s critiques of China’s repressive regime have ranged from playful photographs of his raised middle finger in front of Tiananmen Square to searing memorials of the more than 5,000 schoolchildren who died in shoddy government construction in the 2008 Sichuan earthquake. Against a backdrop of strict censorship, Ai has become a kind of Internet champion. His frequent witty use of his blog and twitter, he is able to organize, inform, and inspire his followers, becoming an underground hero to millions of Chinese citizens. Shows Thursday and Saturday at 7:30 p.m.