The love story between Jill Castle, born Josephine Czinski, and Toby Temple is told through a flashback. The prologue is told by a captain who had retired and became a bistro owner. He loves retelling the story of the day he decided to retire: Years ago, while checking the names of the cruise's V.I.P.s, a series of mysterious events occur, all peaking when he feels something odd about Jill Temple's attitude.
The Templarhauses are German immigrants coming to the USA. Freida Templarhaus is the wife of a lousy poet who would rather write poems than focus on his job as a butcher. Bitter in realizing that her illusions of marrying a poet was false and that her husband is weak, she takes control of the meat shop and becomes the family matriarch. They have a son named Tobias, who is noted to be born with an extremely large penis. Throughout his childhood, Toby has always strove to earn his busy mother's affections, and has learned to gain it through comedy. However, in his teens, Toby has gained a large libido and eventually impregnates a classmate, who unfortunately turns out to be the daughter of the local police chief. Because she has big dreams for her son and doesn't want him to be tied down by a "stupid nobody", she packs up his bags and sends him to the city to become famous, hoping he would send for her as soon as he became successful. She lies to the police chief that Toby ran away. As soon as he makes it to Hollywood, he changes his name to Toby Temple.
Toby's career has a rocky start, as the audience do not appreciate his jokes the same way his mother does. In less than a year, his mother has a heart attack and dies, but he is told by his father that he must not return for the funeral as the police chief will expect Toby to come and will be on the lookout for him, as his daughter is going to give birth at any day. He joins the army and along the way meets Sam Winters, a prominent PR in Hollywood who likes Toby's personality and wants to make him a star. After the war, Toby is forced to continue his career without Sam's help as Sam's secretary will not believe his story and he never gets to talk to Sam. Toby gets his big break when all the better-liked comedians are unavailable to perform for the president of the United States. He gains fame soon after, and in the process catches the attention of Clifton Lawrence, another celebrity producer, and Toby hires him. Sam eventually catches up with him, and they eventually make Toby rich and famous. Toby places his father in a retirement home and immediately begins living the fast life.
Meanwhile, the Czinski Family, a family of Polish immigrants, are expecting their first child. Their baby was born not breathing, and Mr. Czinski dies of shock before the doctors can announce that the baby is alive, but has suffered head trauma and will forever have frequent, unexplained headaches. Mrs. Czinski moves to Odessa, Texas, and became a devout Catholic who believes her daughter Josephine's headaches to be the demon's attempt to possess her. Josephine grows up a beautiful child, to the point that the "Oil People", the upper-class members of Odessa, would love having their children hanging out with her. Josephine is smitten with David Kenyon, the son of the wealthy Kenyons. However, on her thirteenth birthday, she is embarrassed when she gets her menstruation in a swimming party and is scorned by the Oil Children, except for David, who shows sympathy. Soon after, Josephine stops her friendship with the Oil Children and hangs out with the other middle-class residents like herself. She grows into a beautiful woman, and meets David once more after his long period away in college. David and Josephine start a relationship and it climaxes when she and David consummate their love and David proposes. However, when David tells his aging mother about his plans, she insults him about his choice and persuades him to marry Cissy Topping, a fellow Oil Child and former friend of Josephine. David makes a deal with Cissy that he will marry her only until Mama Kenyon dies so he can fulfill her wishes, but unknowingly, Cissy and Mama Kenyon have already planned for this and Cissy has no intention of leaving him. Unfortunately, Cissy asks Mrs. Czinski to do the wedding dress, and before David can tell Josephine, she finds out from her mother and, distraught, leaves for Hollywood under the name Jill Castle.
Toby begins womanizing and unknowingly sleeps with Millie, the loyal mistress of Al, a mafioso. Millie is a beautiful girl that made Toby desperate to sleep with her because she was one of the few who scorned him, but he convinces her when he lies and says that he loves her. Al tells Toby that Millie loves him and wants to marry him and threatens to kill him if he will not. Toby marries Millie, and abuses her during sex as punishment. Scared to get caught cheating, he resolves to stop womanizing and, with Millie pregnant, further strengthens his fame as a family man, which makes younger girls more eager to bed him. He goes to South Korea to perform for U.S. soldiers, under Al's permission, despite Millie about to give birth. Millie later dies giving birth to Toby's stillborn son. With no obligation, Toby begins womanizing once more. He gets a notorious reputation for ruining people for the slightest reasons, and Clifton notices that Toby begins forcing people to praise him. However, secretly, he is lonely as more people come that he fires people who have other engagements other than working for The Toby Temple Show and forces Clifton to drop his other clients so that he would be totally dependent on Toby.
Meanwhile, nobody wants to hire someone like Jill. All the people willing to screen her only want her for sex. She lives in a rundown building with other actors like her, and starts a relationship with Alan, who is later revealed to be an adult film actor. He convinces her with the help of liquor and drugs to do a film with him. In a drunken stupor, she has sex with Alan, a Mexican, and a red-head woman and at the end he writes her birth name on the credits. She only gets minimal small roles, but nothing that makes her recognizable. She realizes that she has to try earning fame their way—by using her sexy body. She is brutally ravaged by a director for a small spot in a major movie, and finally begins her climb to the top.
David wants to reunite with Jill. He is tired of living with Cissy, who only tries to please him but he does not love her and the two openly cheat on each other. Mama Kenyon has died, but when he attempts to force a divorce on Cissy, she attempts suicide, and thus David does not do so anymore. When he sees Jill, they have sex once again and make plans to elope. He rubs it in Cissy's face and, while packing, Cissy takes their car and rapidly drives into a car crash. David is forced to abandon his plan with Jill and tend to Cissy.
Jill sleeps with everyone to get jobs, until she makes it to the Toby Temple Show. Toby is infatuated with her, and goes crazy when she acts indifferently to his charm and wealth. He falls in love with her when he realizes that he doesn't feel alone with her around, and they marry despite Clifton's warnings. Those who have slept with Jill are too scared to admit that they have in fear that Toby will ruin them. Meanwhile, Jill is now plotting revenge against those who have used her.
One by one, she manipulates Toby to destroy the lives of those who have used her without necessarily admitting that she had sex with them all. Her final act is when she convinces Toby to get rid of Clifton (who ignored Jill in her early days and, when she convinced Toby to get her a role, called her a bad actress), as she would be his new manager. Clifton knew she would do that sooner or later, and tries to get on Jill's good side but fails. Jill becomes Toby's new manager. In an act of revenge, Clifton learns about Jill's adult film and bribes a technician to copy the film for him. However, it is too late to tell Toby the truth when he and Jill go on an international honeymoon.
Jill begins acting like his mother. She pushes him to go to all parties and attend all events to the point that Toby suffers a stroke. Jill, still in love with Toby, forces him to re-cope, and he miraculously gets better. It is now Jill who has become the more popular of the two, and in the process meets David once again. Cissy finally leaves David when she meets another man who is not as rich as David but looks like him and loves Cissy. Jill remains friends with David but starts to have feelings for him again when she remembers their history. Toby relapses into a stroke when Jill pushes him once more, ruining his already-faint looks and ultimately paralyzing him into a grotesque. This time Jill has no interest in helping him recover, and accidentally says out loud to him that she wishes he would just die due to his gargoyle-like face, which Toby hears. She begins having nightmares of Toby trying to kill her, and the headaches come back after a long time.
She decides to kill Toby since his expected life span is more than twenty years, and leaving him would ruin her reputation as a heroine. She stages his death and makes it look like an accident while attempting to cure him with exercises in the swimming pool, but Clifton is the only one who sees past the trick. When Jill marries David a few months after Toby's death, Clifton finds out that she killed Toby to be with David. As a last resort, Clifton forces David to watch Jill's adult film. David is revealed to be an extreme racist, especially to Mexicans. It is explained why David had disappeared during Jill's childhood and why, while Jill was working as a waitress in Odessa, he showed extreme disdain when she kissed a friendly Mexican co-worker in the cheek: He caught his older sister Beth having sex with the Mexican gardener and killed him with a letter-opener when he heard a screaming Beth that the two were planning to marry; his mother quietly paid Odessa's jail to make it look like the gardener raped her daughter and committed suicide in jail and sent her deranged daughter to a mental hospital. David had lied to Jill and told her that the gardener raped Beth instead and, since he was very depressed, was sent to college far away. It is revealed why Mama Kenyon could force him to marry Cissy. David breaks up with Jill and leaves on a helicopter. Clifton reveals himself to Jill. In the end, Jill, depressed, hallucinates and sees Toby's face in the water, and she jumps off the boat to be with him and dies. The captain of the boat resigns, starts a bistro, and tells Jill's story to others.