Nikki Heat is the main character in Richard Castle's second successful series of novels, following his Derrick Storm series, and is based on NYPD Homicide Detective Kate Beckett. Both women share similar life histories and personality traits as a result. Castle was inspired to create her after assisting Beckett in solving a murder where the killer made his murders look like the work of a copycat killer.
Castle describes Heat in Nanny McDead (episode 1.2) as "really smart, really good at her job, haunting good looks, and kinda slutty."
Family and Early Years
Much like Beckett, Heat's mother, Cynthia Trope Heat, was murdered when she was in college ten years before she meets Jameson Rook, a world famous journalist based on Richard Castle, except Heat heard the crime take place as she was on the phone with her mother when the murderer broke in to her parents' apartment. At the time, she was home from college on her first Thanksgiving break since her parents divorced. After the murder, she changed her major at Northeastern University from Theater to Criminal Justice and set out to become a police officer and detective. Whenever she arrives at a crime scene, one of her rituals is to take a few seconds thinking of her mother and how that crime impacted her life.
In Frozen Heat, Nikki learns that her mother gave up a promising career as a pianist to become a spy and was murdered when she discovered her handler had betrayed his country.
Hobbies and Interests
As a child, she enjoyed playing the piano, but stopped when her mother was murdered because her mother played beautifully and doing so was too painful for her.
Heat was originally an English major in college, then switched to Theater before her mother's murder. When she was in college, she enjoyed visiting art galleries, an affinity which she carries with her into her time as a cop. Her favorite painting is "Carnation, Lily, Lily, Rose".
She also enjoys going to the movies, especially with her niece, as it provides a temporary escape from the stress of her job.
Prior to meeting Rook, Nikki would periodically sleep with her combat trainer and sparring partner, Don, even though she admits he isn't her perfect lover, but at the same time he never expects much from her after their interludes. In Heat Rises]], she almost gets in touch with him when she worries about the status of her relationship with Rook after he cuts off contact with her to go on assignment abroad then returns to the city and doesn't tell her. Before she can call him, she and Rook reunite after he apologizes to her.
For several months in college, she dated a Croatian transplant named Petar Matic. The two reconnect in Naked Heat and Petar asks Nikki if she wants to get back together, but Nikki turns him down, saying she can't trust him since he tipped off a person of interest in the most recent murder she and Rook were investigating. In Frozen Heat, Nikki and Root encounter him again and Nikki eventually discovers that, when she was in college, he was working as a spy and only dated her to get closer to her mother. Despite Nikki's falling for him, he never loved her. After he admits his complicity in Cynthia's murder, tries to kill Nikki, and Nikki arrests him, he is poisoned in jail so he won't reveal all he knows about Cynthia's death.
Relationship with Rook
As much as she tries to prevent it from happening, she and Rook sleep together and fall into a relationship. They break up in the intervening time between when Heat Wave and Naked Heat take place over the publication of Rook's article on her and her squad. Besides being mostly about her and pushing her squad mates, Detective Ochoa and Detective Raley, into the background, Nikki feels it hits too close to home by exposing the death of her mother and how it impacted her life. The two reconnect in Naked Heat when a gossip columnist Rook is shadowing for another article is found murdered and he convinces Nikki to allow him to help her with the investigation. The two rekindle their romance when Rook apologizes to Nikki for not understanding how his article made Nikki's life difficult.
At the beginning of Heat Rises, Nikki is frustrated at Rook's lack of contact while he is abroad working on a story and even more so when she discovers that he returned and didn't tell her. When she confronts him about it, he apologizes and explains that his method is to sleep heavily and write furiously in seclusion, but that since she has come into his life, he will have to change his style. She forgives him and he helps her investigate the death of a priest in a fetish club, the death of her mentor, Captain Montrose, and to recover her badge when Internal Affairs strips her of her police powers after suspecting her of being involved in the crimes. She is nearly shot as she and Rook attempt to bring in the people responsible for the crimes, but Rook knocks her out of the bullet's path and is shot himself.
In Frozen Heat, he has made a near full recovery.
The first book Castle writes featuring Heat as the main character is Heat Wave. The premise of the story is a real-estate mogul plunges several stories to his death and Heat and her team, consisting of Detective Raley and Detective Ochoa, collectively known as Roach and based on Beckett's squadmates Detective Kevin Ryan and Detective Javier Esposito respectively, are assigned the case. Tagging along for the ride amidst a nasty New York City heat wave, is famous First Press magazine correspondent Jameson Rook, based on Castle himself. Rook shadows Heat for a magazine article he is working on involving NYPD Homicide Detectives. The relationship throughout the story closely mirrors that of Castle and Beckett, except that midway through the book, Rook and Heat give in to their attraction for each other and sleep together. By the time the two solve the case, they are both confronted with whether or not to continue their relationship, since Rook has all the research he needs for his article and therefore, does not need to shadow Heat and her team anymore. As the book ends, they decide that their mutual attraction is just too great, and they kiss and spend the night together.
Other characters in the book are Medical Examiner Lauren Parry, inspired by Beckett's best friend Medical Examiner Lanie Parish, Captain Montrose, alter-ego of Beckett's boss, Captain Roy Montgomery, and Rook's diva mother derisively known as The Grand Damn and based on Castle's mother, Martha Rodgers. The only character from Castle and Beckett's world who does not appear prominently in the book is Castle's daughter Alexis, though Heat does refer to having a young niece.
The book was a runaway best-seller both in the fictional world of the Castle TV show and in real life, where it spent over 20 weeks on the New York Times Best Seller List.
Naked Heat is the second installment in Castle's Nikki Heat series. After Rook's article on Heat and her squad is published, Nikki finds that she has lost a good degree of her anonymity and some of the respect of her partners Raley and Ochoa, since the article focused on her. As a result of the backlash, she cuts off contact with Rook and the two end their relationship. Then Heat gets called in to investigate the death of a man who looks to have been killed by a wild dog. Heat makes the connection between the man's wounds and a coyote she spied while on her way to the crime scene. Just after being assigned that case, she gets another call about suspicious activity in the townhouse of a renowned gossip columnist. Heat, Raley and Ochoa respond and not only find the dead body of the columnist, but Rook waiting for them. Since he had been shadowing the columnist for his latest article, Heat agrees to let him assist her with the investigation. As much as she tries to fight it, as the case progresses, Heat discovers that she still has feelings for Rook and the two rekindle their relationship, just before they cross the path of one of Heat's ex-boyfriends. By the end of the book, Heat and Rook have solved the crime, Rook is busy working on his article about the gossip columnist, and Heat realizes that she cannot trust her ex, leading her and Rook to sleep together again.
Upon its release, Naked Heat shot to #7 on the New York Times Best Seller list, emulating the success of Heat Wave.
The third book in Castle's Nikki Heat series finds Nikki working solo and anticipating her boyfriend Rook's return from having been on assignment out of the country and out of touch with her. When she and Raley and Ochoa catch the case of a parish priest found dead in a fetish club, they all discover that the murder has a worrisome connection to their boss, Captain Montrose. At the same time, Nikki awaits the results from the lieutenant's exam she recently took and rumors are she aced it, making her eligible for a promotion and taking off her the streets as a regular homicide investigator. She then discovers that Rook is back in town and while he had time to have lunch with an attractive woman, he apparently hasn't had time to return her phone calls. Just as Nikki considers calling her "trainer with benefits", Don, Rook appears in her apartment, apologizes to her, explains that his lunch companion was his publisher, and they spend the night together when she forgives him. As the investigation progresses, everyone gets nervous as Internal Affairs begins looking more closely at Montrose's background. Their interest stops when he is found murdered in his squad car, leaving everyone at the precinct, especially Nikki, for whom Montrose was a mentor, devastated. Her devastation is compounded when Internal Affairs strips her of her badge, leaving Nikki lost and suspicious of a departmental cover-up. She turns to the only man she trusts, Rook, who agrees to help her, since his work on his most recent article is complete. They also enlist the help, off the record, of Nikki's squad, Detectives Raley and Ochoa. Through their work, Captain Montrose is exonerated, but Nikki's ally, Phyllis Yarborough, a Deputy Commissioner in the department, is revealed to have been behind the murders of the priest and Captain Montrose. In the takedown of the professionals Yarborough hired to commit the murders, Rook is seriously wounded by a gunshot to the chest. Nikki also discovers she passed the lieutenant's exam with flying colors, but turns down the promotion since, during the time she was without her badge, she realized she loved working the streets too much to give it up. The book ends with Captain Montrose's funeral and with Nikki reading Rook's most recent Victoria St. Clare book to him as he lays unconscious in the hospital.
The fourth book revolves around Nikki investigating the death of a college friend of her mother's as well as her mother's murder itself, which, having been unsolved, lead Nikki to join the police force.
Heat Wave Movie
Actress Laura Prepon has been cast to play actress Natalie Rhodes, who will play Nikki Heat in the movie version of Heat Wave.