Paz Roble, a kind, hard-working and honest woman from whom her husband, Fermín, takes her newborn daughter. Fermín has a large debt with some lenders and to pay it he decides to sell his daughter to Mauro Nicoliti. This plagiarism is orchestrated by Geneva, Mauro's adoptive sister. She lost her first-born daughter in childbirth and does everything to replace her dead daughter and keep her husband's fortune. On the other hand, Esteban Villa de Cortés loses his wife and becomes a widower with his three children. Elvira Moncada, Esteban's mother-in-law, holds him responsible for the death of her daughter. After a series of unexpected events, Esteban and Paz meet in the neighborhood where she lives with her family. The chemistry and great understanding that exists between them makes it inevitable that they will fall in love.
Paz accepts the money that Fermín offers him and confesses that he rescued little Luna, he asks to meet her. Luna dreams that her friend Monito is in danger, so she decides to leave Paz's house to rescue him. Elvira invites Geneva to eat and takes the opportunity to take a saliva test to confirm if she carries her blood. Paz proposes to her sister to win Mauro's heart so she can learn about the plans she has against Sam.