Yvette and her younger sister Charlotte are abandoned by their parents at a young age. Charlotte's amazing singing voice earns them little money, until she is discovered by the patron of the Opera Populaire. The sisters both land jobs working at the Populaire, Charlotte singing and Yvette working backstage. When Yvette starts hearing an angelic voice calling her name, she tries to figure out if the voice is a fragment of her imagination, or if it's reality.