In 1977, Maria Callas, the most famous diva in the world, lives confined in her Paris apartment. Larry Kelly, a producer friend, offers her to sing "Carmen" in a televised concert. Unfortunately Maria's voice, tired and worn by years and strain, is not what it used to be. Larry knows the way around the problem : a technical stratagem will create the illusion. Maria, disregarding her friend Sarah's warning, agrees with the idea and the show is a tremendous success. With that in mind, Larry now considers a new version of "Tosca". But this time, Maria objects to the subterfuge. Her decision will mark the beginning of the end for the legendary singer.