(Isabelle Huppert) is a piano teacher at a prestigious music school in Vienna who still lives with her overprotective and controlling
mother (Annie Girardot). Lonely and alienated, Erika finds solace by visiting
sex shops and experimenting with masochism.
At a recital, she befriends Walter (Benoît Magimel), a handsome young man, whom she seduces and begins an illicit affair with. As Erika slowly drifts closer to the brink of emotional disorder, she uses the love-stricken Walter to explore her darkest sado-masochistic fantasies.