Amid the lavish, boisterous atmosphere of a masked ball at the Paris Opera in the early twentieth century, a doctor, concealing his true intention, happens to catch sight of his wife, Irène, disguised as Pierrot. Following her, he tries to understand whom she is looking for and why she mingles so freely with strangers. What emerges from behind the mask is not an ordinary romantic secret, but the individual’s longing—especially a woman’s—for independence and freedom, as well as the limits of her husband’s jealousy and self-deception.