Isabel devises a plan against Heitor and counts on Augusto's help.

Cecília becomes interested in Felipe and starts taking music lessons from him. Iolanda tries to warn Cecília about Augusto's bad reputation. Vicente tells Augusto that Mariana had Júlia follow him. Cecília confesses to Isabel that she does not want to marry Heitor. Isabel promises Cecília she will arrange a meeting between her and Felipe. Mariana feels desire for Augusto.

Isabel encourages Cecília to meet with Felipe. Mariana asks Augusto to stay away. Felipe and Cecília declare their love for each other. Júlia hands Augusto the letters Iolanda wrote to Mariana. Isabel mentions to Iolanda that Cecília and Felipe have exchanged notes. Augusto promises Isabel that he will sleep with Cecília before their wedding.

Isabel convinces Iolanda to take Cecília to Consuelo's estate. Augusto tries to seduce Mariana, who remains faithful to her husband. Isabel tells Cecília that Augusto and Felipe are friends. Augusto seduces Cecília.

Cecília tells Isabel about Augusto and confesses that she enjoyed spending the night with him. Isabel brings Collete D’Or to the charity show, and Otávio is furious. Isabel promises to spend the night with Augusto if he proves that he seduced Mariana. Mariana leaves Consuelo’s house without anyone noticing. Mariana confesses to Consuelo that she loves Augusto.

Mariana and Augusto give in to their passion. Cecília mentions to Isabel that she still receives letters from Felipe. Mariana confesses her feelings to Augusto. Mariana admits to Consuelo that she cheated on her husband. Augusto hides the letter he received from Mariana from Isabel. Cecília meets Felipe in secret. Augusto swears to Mariana that he is not in a relationship with Emília. Mariana and Augusto decide to run away together.

Isabel lies to Cecília, claiming it is impossible for the young woman to be pregnant. Isabel deduces that Augusto plans to run away with Mariana and humiliates him. Mariana attempts to take her own life and is rescued by Júlia. Cecília feels jealous upon learning from Iolanda that Augusto and Mariana were lovers. Felipe tells Augusto that he spent the night with Isabel. Augusto and Isabel declare war on each other.

Isabel becomes angry when she realizes that Augusto orchestrated things to prevent Felipe from meeting her. Isabel tells Felipe that Cecília is pregnant by Augusto. Cecília tries to apologize to Felipe, but the teacher declares that he can no longer be with her. Isabel advises Cecília to hasten her marriage to Heitor and conceal her pregnancy. Cecília insults Isabel and is thrown out of her aunt's house.

Cecília turns to Consuêlo for help after discovering she is pregnant. Augusto ends his partnership with Isabel. Augusto and Felipe face off in a decisive duel. Near death, Mariana is shocked by the news of the duel.

Felipe discovers Isabel's wicked deeds and decides to see justice served. Augusto and Mariana are laid to rest, and Isabel misses her lover. Fulfilling Augusto's request, Felipe shows Consuêlo and Otávio the letters that incriminate Isabel. Isabel is publicly humiliated. Cecília and Heitor get married. Consuêlo laments the tragic end of the relationship between Isabel and Augusto.