Angela is a charming and beautiful young school teacher, with a sweet but firm character. Her only living relative is her mother Delia, a sick and embittered woman. On her deathbed, Delia makes Angela swear an oath that she will rise to the top in life, and with her last breath she curses Emilia Santillana, the woman who stole Angela's father away from her.
Upon hearing at last the name that Delia had always refused to reveal, Angela vows, with chilling determination, that she will not rest until she has found this woman and made her pay for ruining her mother's life. Emilia Santillana lives in the city of San Miguel de Allende, where she runs a very successful silver business. She owns a mine and a factory.
One day, Angela arrives at Emilia's company seeking employment. Yolanda Rivas, Emilia's right hand, takes pity on the seemingly sweet and shy young girl and persuades her boss to hire her. Little by little Angela wins her trust. Angela is convinced of her righteousness and uses her beauty and her growing influence within the business to systematically destroy Emilia's world.
Only one person mistrusts her and is not seduced by her apparent innocence. Mariano Bautista, a young engineer who works in a silver mine. Angela tries to ignore her attraction for Mariano, but finally comes to realize that she truly loves him.
And, for the first time in her life, the promise of happiness seems within her reach when Mariano confesses that he too has fallen in love with her. Nevertheless, the oath she swore over her mother's grave binds her to her destiny, and Angela is now powerless to stop the tidal wave of destruction and suffering that she herself has unleashed.