Pianist, composer and archivist Percy Grainger was publicly known for a brief concert career, several interesting contemporary classical compositions, and researching and documenting a wealth of English folk music. Privately, Grainger's life was tumultuous and unconventional, as chronicled in the film Passion. Set in London in 1914, shortly before the outbreak of World War I, Percy Grainger (Richard Roxburgh) is making a name for himself as a pianist; his recitals are known for his fiery performing style and fondness for dropping non-traditional pieces into his repertoire. Percy's career is guided by his mother, Rose (Barbara Hershey). Their relationship goes far beyond the normal bounds of family or business; Percy and Rose are also lovers, with Percy satisfying Rose's sado-masochistic impulses (which are aggravated by the fact she's contacted syphilis). Percy is also attracted to Alfhild (Claudia Karvan), who is uncooperatively married to his best friend, Herman (Simon Burke). Karen (Emily Woof), a lovely piano student, is interested in being tutored by Percy; Alfhild and Herman think this is a fine idea, and surprisingly so does Rose. However, Karen soon becomes Percy's lover as well as his student, and when Rose discovers Karen is willing to satisfy Percy's erotic appetites for pain, she no longer approves of Karen's presence. The film follows Grainger's life until he moves to New York City, where he spent most of his life until committing suicide in 1961.