Maddalena Natoli (Anna Magnani) goes back to Vulcano after eighteen years. Firmly determined not to put behind the new comer's dubious past, the islanders grow more and more hostile as days go by. Maddalena's only relief is found in the love of her sister, Maria, who was just a baby when she left and of her younger brother who she meets for the first time. The three of them work in the pumice quarry amid the islanders' backbiting which soon leads Maria to learn the truth about her sister's mysterious past. Things come to a head when Donato the diver makes his appearance and Maria falls in love with him. Tragedy is reached when Maddalena attempts to save her younger sister from a well known outcome. The film is also known for the sentimental backstage bustle, since just steps away in Vulcano, Rossellini was directing Ingrid Bergman in Stromboli, terra di Dio marked for being the actress's first film and by the recent stormy break up of the director and a furiously jealous Anna Magnani.