Hipólita Díaz is a young woman who lives in Panama with her husband, Antonio, and her mother-in-law, Adelaida. Antonio suffered from sexual abuses when he was a child, so he isn’t able to consummate his marriage.
Adelaida wants to have a grandchild, as Antonio will not inherit the fortune of his uncle, Próspero, unless he sires a son.
Luis Manrique y Arellano is a noble Mexican who came to Santa Rita to close a deal under orders from his cousin Diego, the Count of Guevara, without knowing that the trip was a pretext to have him killed.
When Luis is captured by Adelaida's servants while fleeing from justice, she orders him to take Antonio's place in Hipólita's bed, or she'll turn him over to the authorities.
So Luis goes to Hipólita's bedroom, intending to escape from a window. It's very dark, she awakes upon hearing him try to escape, she doesn’t see him very well and she believes he is her husband.
He makes love to her to keep her quiet, and then makes good his escape. But before he leaves, Hipólita discovers that this man isn’t her husband, but an escaped prisoner.
Luis departs, without Hipólita seeing his face or knowing his name – but Luis knows hers. She is furious with her mother-in-law for what she has done, but she can’t change what happened.
Some weeks later, Hipólta finds out that she is pregnant with Luis's child, so she decides to leave home with her maid, Adalgisa, and go to Mexico, where her family lives.
There, she has her child, Rafael, and finds her mother and her sister, but they aren’t very thrilled to see her. Hipólita was Asunción's illegitimate daughter, so she sent the girl to Panama to be raised by her grandmother, so that no one in Mexico could know that she had a daughter outside of wedlock.
When Hipólita arrives in Mexico, she has to fight against her stepfather's hate and her mother's desperation when she finds out that there's another bastard in the family.
Luis also lives in Mexico: he is a rich man, cousin of the count of Guevara, and there is much mystery about his relationship with his mother, Juana, who appears to hate her own son and support the count against him at every turn.
Hipólita and Luis meet again and, although she doesn’t recognize him, he recognizes her and he suspects that the child that Hipólita has with her is also his son.
They don’t get on very well initially, but later, they fall in love with each other. Luis feels that he has to tell her that he is her son's father, but he can’t do this, because if he did, Hipólita would hate him.
The eventual recognition of Rafael as Luis's son, the reason why Luis's mother detests him, and the plots of the Count of Guevara against Luis are played out against the background of Luis's and Hipólita's attempts to be together.