Unchanged Heart in Life and Death.

Probably the most sheerly entertaining of all the films made in 1930s Shanghai by 'underground' leftists, this riff on The Prisoner of Zenda is funny and engaging from first to last. The irresistible Yuan Muzhi (director of Street Angel the following year) plays both Li Tao, a revolutionary on the run, and Liu Yuanjie, an American-Chinese teacher visiting China with his fiancée. Liu is mistaken for Li and thrown into jail; Li teams up with the fiancée (Chen Bo'er, Yuan's real life wife) to get him out of prison and into the spirit of revolution. Ying Yunwei (who started out playing female roles in Chinese opera) uses chiaroscuro lighting, highly mobile camerawork and zippy pacing to give it maximum impact, but it's Yuan who really keeps you watching.