On Christmas Eve 1944, Nelly, performing a concert for French prisoners at Ravensbrück camp, is asked by one of the audience members to sing a piece from Madama Butterfly. Nelly performs the aria “Un bel di vedremo,” and this performance leads to her meeting Nadine. The relationship that begins between the two women continues despite the hardships of the war. After the war, Nelly reunites with Nadine, and together they emigrate to Venezuela. This relationship, kept secret within the family for many years, is eventually discovered by Nelly’s granddaughter, Sylvie Bianchi. By examining her grandmother’s personal belongings, Sylvie uncovers the love and lives of Nelly and Nadine.
