A beautiful and intelligent young woman named Rosario falls in love with her boss, Alejandro, a prominent lawyer twenty-one years older than she. Rosario does not know that Alejandro is the same man whose mother, Magdalena, was engaged to marry twenty-one years ago; Magdalena has kept her romance with Alejandro in secret. In the past, Alejandro broke his engagement to Magdalena on learning that she had become pregnant with Marcos as a result of rape. Alejandro, convinced that he could never accept, nor love, a creature that was begotten by his worst enemy decides to abandon it. The irony is that years later that child, Rosario, would become the great love of his life. The love of a young woman for the man she should never have fallen in love with; the love of a man towards the woman he swore he could never love; and the conflict of a mother when she meets the man she was about to marry and who is currently her daughter's boyfriend.