Directed by Lou Ye, Zi Hudie revolves around the underground faction of anti-Nipponese fighters in 1930s Shanghai, just prior to the onset of the Sino-Japanese war. It's only the beginning when Cynthia (Zhang Ziyi), a young Chinese woman, learns the news of her lover Itami's (Toru Nakamura) rapidly approaching return to the military. In a second and even more devastating blow, Cynthia's brother, a contributor to an anti-Japanese newspaper, is killed by a Japanese activist. Three years later, switchboard operator Tang Yiling (Li Bingbing) and Situ (Liu Ye), her fiancé, are introduced to Cynthia after inadvertently heading into a protest held by a resistance group code-named Purple Butterfly, of which Cynthia (who has since changed her name to Ding Hui) has become a part. Ultimately, a botched assassination attempt leaves Situ with a mysterious briefcase; now a suspect himself, Situ is arrested by none other than Itami, who, after reuniting with his old flame, has no idea of her role in a complicit plan to have his boss (Kin Ei) assassinated.