Nino, in his fifties, handles a coin to a dishevelled old woman in the street, forgetting all about it, but she seeks him out and insists on repaying the money back. She finally reveals she is Anna, a girl with whom Nino had been twenty years before, now unrecognisable. That evening the concierge of the house where Anna used to live is brutally murdered and the police suspect her nephew to be the murderer. Meanwhile, Nino tells his friends about the strange meeting with Anna but one of them, a doctor, informes Nino that Anna had died of a cancer years before. Nino's curiosity is aroused. He discovers she had been married in another town, and telephones the home, only to hear Anna's voice answering the phone. He visits her, and finds her as young and as beautiful as when they had been in love. They spend a day together on a boat along the river, as they used to do in the past. And discussing the death of the concierge. Anna confesses that his nephew had raped her years ago and the concierge had arranged for an abortion. A false movement causes the boat to overturn, and Anna drowns. Nino goes to inform her husband, only to be told brusquely that Anna had been dead for three years now. Nino goes to the cemetery and finds her tombstone with her photo, the image of the old woman in the street. The police drag the river and find a corpse, but it is that of the concierge's nephew: Anna is revenged. Nino returns home, convinced he has seen a ghost, but is unable to get rid of her presence. She telephones him constantly; the phone rings even when it is disconnected. Nino goes out of his mind, and is interned in a clinic. When he looks up at his nurse, he sees Anna again.