Valentina Villalba (Lucero) is a beautiful woman with a fortune
that her parents left her when they died. She has a mansion in Mexico City, where she lives
with her aunt Isabel Dorantes (Silvia Piñal) and her cousin Ivana (Gabriela Spanic). Valentina is engaged to Alonso
(David Zepeda), but she doesn't know that Alonso is cheating on her with Ivana. Ivana has an additional lover, Oscar Ampudia,
who is married. Ivana ends up running over Oscar with his car. Instead of simply informing her that he has changed his mind,
Alonso stands up Valentina at their wedding. He has planned to run away with Ivana, but he ends up taking a different flight.
Valentina decides to isolate herself at the hacienda Los Cascabeles, where she starts a new life.
When she arrives at the hacienda she finds Rosendo Gavilan (Sergio Goyri) abusing Iluminada, a servant that works at Los Cascabeles.
Rosendo has raped Iluminada before. Valentina lays down the law and kicks Rosendo out of the hacienda. But eventually she
hires him as her foreman. Most of the people of the region hate Valentina because of the things Rosendo does as her foreman,
to their mind following her orders. They have given her the name "La Vibora", Spanish for viper or snake. Isabel,
Ivana, and their servant Benita, eventually move to the Cascabeles.
Valentina meets Jose Miguel
Montesinos, a rich land owner. She wishes to purchase his land, but he adamantly refuses. Jose Miguel's parents, Federico
and Leonor Montesinos, move into their hacienda. Leonor wishes to return to Mexico City, but Federico Montesinos has only
a short time left to live and wants to spend his remaining days on his hacienda. Jose Miguel becomes attracted to Valentina.
Federico Montesinos was once in love with Isabel Dorantes and it turns out that he still is in love with her. Federico Montesinos
dies when Rosendo sets fire to the home of Sabino, a former employee of Jose Miguel whom his mother Leonor had fired. Valentina
is blamed for killing Federico.
Valentina begins to fall in love with Jose Miguel after accidentally
shooting him. Soon Ivana begins to fall in love with him as well. Rosendo decides he wants Valentina, and he begins to challenge
Jose Miguel for her. Jose Miguel and Valentina finally agree to marry each other, but Jose Miguel's mother does not approve
of the marriage. Ivana and Rosendo also disapprove of the marriage and join forces to stop it. While Jose Miguel is gone to
Mexico City to sell his house, a woman named Arcelia Olivares tells Valentina that she and Jose Miguel had a relationship
and that she has his son. Valentina breaks off marriage plans with Jose Miguel because of this. But in reality it was only
a plot masterminded by Leonor and Ivana. In spite of everything, Valentina still loves Jose Miguel.
Soon
Alonso (David Zepeda) comes back into the picture. He promises that he will not go back to Mexico City without her or her
forgiveness. Jose Miguel, Rosendo, and Alonso begin to fight for Valentina's love. Alonso and Jose Miguel go for a short
while to Mexico City. Chuy, the son of one of Jose Miguel's workers, is hurt in an accident, and Jose Miguel comes back
to San Pedro to see him. In the hospital room, brought together by the accident of Chuy, Jose Miguel and Valentina decide
to get back together. Ivana still wants Jose Miguel and plots to convince him that she is carrying his baby. To accomplish
this, she goes to Mexico City and sleeps with an old friend who is a doctor (although he is married) in order to get pregnant
and pass off the baby as Jose Miguel's. But she doesn't get pregnant.
Jose Miguel and
Valentina decide to get married after Chuy recovers. Jose Miguel spends the night at Valentina's house, where they engage
in passionate sex. Ivana is jealous. She tells Jose Miguel and Valentina that she is pregnant with Jose Miguel's child,
and Valentina breaks up with Jose Miguel again. Ivana tries to sleep with Alonso, but Alonso kicks her out. She sleeps with
Rosendo. Later she seduces the detective who is investigating Oscar's death in order to try to get pregnant once and for
all. Unfortunately for him, he falls for Ivana. Still, she cannot get pregnant.
Ivana's guilty
conscience over killing Oscar causes her to see his apparition many times, which degrades her mental health more and more
as time goes by. She ends up killing Benita, beloved servant and "nana" of Valentina and Ivana, while having a hallucination
and thinking that Benita is actually Oscar. Rosendo witnesses the murder.
Rosendo kidnaps Valentina.
She is eventually rescued by Sabino and Jose Miguel's mother Leonor, who turns out to have been Rosendo's lover when
they were young. Jose Miguel runs across the three as they head homeward. Then Rosendo shows up. While Rosendo and Jose Miguel
are engaged in a death battle, Leonor tells Jose Miguel that Rosendo is his father. While Rosendo is inside the cave where
he had kept Valentina hostage, someone blows up the cave, and everyone believes he is dead.
Ivana
comes to realize that she is not going to be able to get away with murder after all, so she ends up hanging herself. The autopsy
shows that she was not pregnant.
After that things change. Jose Miguel's mother apologizes
to Valentina and to Jose Miguel and apparently intends to change her ways. Valentina and Jose Miguel get married. However,
during the ceremony Rosendo shows up, extremely disfigured, and tries to kill them. Alonso jumps Rosendo, enabling Jose Miguel
and then the police to disarm him. The police take him away. Valentina and Jose Miguel live happily ever after. They are shown
with their twins at the end of the story.
