Sandra is hosting a cocktail party when she suddenly becomes aware that someone is playing César Franck's Prelude, Chorale and Fugue. The piece used to be in the repertoire of her pianist mother, and now it fills her mind with bitter memories. As the film – Vaghe stelle dell'Orsa (Sandra) – progresses, she is forced to redefine her relationship with her family and her husband, her past and her future. When she finally decides to sever her ties with the past, she pays a high price for her freedom.

The problems of relating to time and history constitute one of the most pertinent themes of Luchino Visconti's (1906–76) artistic output. He could remember how as a small boy he could hear his mother play that piece after bedtime. The main theme of Franck's Prelude has much the same function in Sandra as the tea in which Marcel soaks his “petite madeleine” in Proust's Remembrance of Things Past. There the mere sensation of the warm liquid on the lips produces “an exquisite pleasure” that makes “the vicissitudes of life … indifferent, its disasters innocuous, its brevity illusory.”

Both Visconti and Proust were keenly aware of the perpetual sense of loss that is an inextricable feature of life, but as Mikael Enckell has pointed out, the perspective of both also emphasizes "the continuity of existence: What appears to be irrevocably lost returns through its very passing, as memory, imagination, and works [of art].”