Flora lives a life of luxury with an important conductor who is not her husband since she is married to Carlos, who enlisted in the Blue Division to fight the Soviets in WWII and was reported missing. But her tranquility is interrupted when she is followed by a man who claims to return from Russia where he was a prisoner, telling that Carlos lives and sends a letter to Flora. From there the mystery of reality and the lie disturb Flora, bringing into play the real identity or not of the one who brings the letter, whether he is a communist agent or tells the truth about her husband.