Maggie Cheung and Tony Leung Chiu-wai play the lead characters, who move into an apartment building on the same day in 1962 and discover that their spouses are having an affair; over the next four years they develop a strong attraction. Teo writes that the film is a study of "typical Chinese reserve and repressed desire", while Schneider describes how the "strange relationship" is choreographed with "the grace and rhythm of a waltz" and depicted in "a dreamlike haze by an eavesdropping camera".