Jac Naylor


Jac Naylor is a fictional character from the BBC medical drama Holby City, portrayed by actress Rosie Marcel. She made her first screen appearance during the series eight episode "Bird on a Wire", which was originally broadcast on 22 November 2005. The character is introduced alongside Luke Roberts and Tom Chambers as Joseph Byrne and Sam Strachan, respectively. Jac is characterised as a highly ambitious, forthright surgeon who is career-oriented. Her backstory states that her mother placed her in foster care aged twelve. Jac struggles to form relationships, but establishes rivalries and uses sexual manipulation to her benefit, engaging in romances with multiple colleagues.
Marcel took maternity leave in 2014 and Jac temporarily departs in the seventeenth series episode "Go the Distance", originally broadcast on 14 April 2015, after reuniting with Jonny Maconie. Marcel returns for two appearances during her maternity leave, before returning in the eighteenth series episode "A Delicate Truth", originally broadcast on 24 November 2015. Marcel worked with producers to emphasise Jac's bitchy characterisation on her return. After noticing a connection between Marcel and Alex Walkinshaw, Jac was paired with his character, director of nursing Adrian "Fletch" Fletcher, in 2017. Additionally, Jac has made multiple appearances on Holby City sister shows, HolbyBlue and Casualty.

Storylines

Jac arrives at Holby City Hospital as part of a team performing a hemicorporectomy. She is initially unsuccessful in securing a permanent position as a registrar, but returns to the hospital in this capacity several weeks later. Jac develops a rivalry with her fellow registrar Diane Lloyd, which intensifies when they both apply for the same consultant post. Neither are successful, but Jac is disappointed when Diane is later promoted above her, to locum consultant and later to permanent consultant.
Unable to cope with the pressure of his job, cardiothoracic surgical registrar Joseph Byrne accidentally overdoses, and is saved by Jac. She becomes romantically involved with him, hoping to ingratiate herself with his influential father, Lord Byrne. Taking this further, Jac later lies to Lord Byrne, claiming that she and Joseph have separated, resulting in Jac sleeping with Lord Byrne. She attempts to blackmail him into securing her a consultancy. Lord Byrne falls in love with Jac, and confesses their affair to Joseph, who pleads with her to dump him and offers her the chance to resume their relationship. Jac declines, choosing to be with his father. Diane commits suicide, and Lord Byrne attempts to use his influence to secure her position for Jac, but has a stroke before succeeding. After a failed attempt at making amends with Joseph, he has a heart attack and dies. Jac refuses to show remorse for destroying Joseph's family, resulting in him hitting her. She uses the resultant bruising to garner sympathy and secure a position on a stent trial, She is attacked by patient Alan Clooney during the stent trial, who unsuccessfully attempts to rape her. Jac declines to report it, but assaults him when he returns to the hospital six months later. Jac claims to be suffering from residual headaches from Joseph's attack and blackmails him to make his mother support her application for a consultant post, which backfires when she is instead granted sick leave.
When Clooney is later found stabbed through the heart, Jac is arrested for attempted murder. She is cleared when a young victim of his confesses to the attack. Suspicious of ward sister Faye Morton, with whom Joseph has begun a relationship, Jac follows her to a secret assignation, accidentally crashing her motorbike en route. She spends some time in intensive care and has to walk, aided by a crutch for several months afterwards. Joseph and Faye become engaged, but their relationship deteriorates. An intoxicated Joseph ends up in bed with Jac, and she manipulates him into believing that she is expecting his baby. Her lie is uncovered when she is treated as a patient, having been knocked down the hospital stairs. Soon thereafter, she and Joseph are trapped in an operating theatre together, when it is discovered that their patient had been transporting contaminated waste. They declare their love for one another, but Joseph states that he has moved on with Faye, leaving Jac distraught.
Jac shares a kiss with foundation doctor Oliver Valentine, but their relationship doesn't go any further. When her estranged mother, Paula Burrows, is admitted with kidney damage, Jac reveals that she was abandoned aged twelve and placed in foster care. She agrees to a kidney transplant to save her mother, who deserts her again following the operation. Jac discovers that she has a younger half-sister but detaches herself from her family for good. Having transferred back to general surgery, Jac develops a reluctant friendship with locum registrar Sacha Levy, who successfully recommends her for a locum consultant position. Afraid of being demoted after making a clinical error, Jac blames the mistake on ward sister Chrissie Williams, the mother of Sacha's son, which leads to the termination of their friendship.
Faye becomes pregnant with Joseph's child but has a breakdown and refuses to leave the psychiatric unit she has admitted herself to when she goes into labour. Jac convinces her to receive proper medical care, saving Joseph's son. Grateful for her intervention, Joseph shares a kiss with Jac and they resume their relationship. Jac intercedes upon discovering that Faye is planning to leave the country with the baby, named Harry and takes them back to the hospital, where Joseph convinces her to leave Harry with him. He decides to move to the countryside and become a general practitioner, so he will have more time to spend with Harry. Jac declines to accompany him, valuing her career over a quiet family life, but is devastated by Joseph's departure. She briefly resigns when her locum consultancy is rescinded, but upon failing to find work elsewhere as a result of her reputation, returns once more as a cardiothoracic registrar. She begins a rivalry for a cardiothoracic consultant position with new registrar Sahira Shah. A position that she later wins, Jac receives a box containing fancy stilettos and a bottle of champagne from Connie Beauchamp, with a note about the shoes saying "Fill them! x".
Jac helps Sahira set up a Cardiac Trauma Unit as a way of saving cardiothoracics when Darwin Ward is threatened with a merger with St. James'. In the wake of the plastics scandal, Jac and Sahira continue to use CTU until Henrik Hanssen dismantles the project, following Sahira's departure. Jac helps Sacha rekindle his love for Chrissie by giving him a lift to the airport. When Jac berates new F1, Tara Lo, Hanssen refers her onto a people skills course and she is forced to publicly apologise to Tara. On the course, Jac meets Jonny Maconie who claims to be a neurosurgeon from St. James. Despite their different work attitudes, Jac and Jonny end up in bed together. However, Jac tells Jonny afterwards that this "never happened." Jac is shocked when Jonny turns up at Holby as a nurse however they continue their relationship. Jac is offered a six-week research post in America. Jac assists Mo Effanga when she gives birth. Jac continues to be a brutal mentor towards Tara. With her relationship with Jonny intensifying, Jac worries that the hospital is gossiping about her private life and takes out her issues on Mo. Jac worries that she might be pregnant with Jonny's baby and, following pressure from Jonny to take a pregnancy test, she tells him that it was a false alarm. Jac is invited to Sacha's stag do and makes no secret of her opinion of Sacha's bride-to-be, Chrissie.
Following the negative publicity bombarding Holby in the wake of Hanssen's press release, Jac becomes concerned that he is not the leader she thought he was and makes her concerns known to the chairman of the Holby Trust, Terrence Cunningham. Jonny is caught between Jac and Mo and, with her professional detachment called into doubt by a patient, Jac takes a drastic step in her relationship with Jonny. Jac is annoyed to discover that Jonny is coping well with their break-up and in an effort to rile him, she goes out with a new man. Jac begins to rekindle her relationship with Jonny but their drink is called off when new acting CEO, Imelda Cousins lets slip that it was Jac who voiced her concerns about Hanssen to Cunningham. Jonny and Jac get back together however Jac once again messes things up, when she hears that Joseph is getting married, by sleeping with the paediatrician Sean. Jac tries to do the right thing and tells Jonny about her on night stand before he found out any other way but he still gets mad so Jac decided to travel to Japan to do some training on new medical techniques. Jac comes back to work a day early to put her training in to use and catches Jonny off guard. After Jac has an accident on the ward she tells Jonny that she loves him and they continue with their relationship. However Jac starts to experience abdominal pains that she worries is something to do with her kidney but when the ultrasound comes back clear she refers herself to obs and gynie and is diagnosed with endometriosis. Jac keeps her diagnosis to herself and after a confrontation outside theatre Jonny dumps her.
When Tara Lo sends an email to everyone, informing them of her brain tumour and that she will be undergoing surgery to have it removed, Jac is extremely surprised and upset by the news. When Tara dies in surgery after complications, Jac is deeply saddened despite the fact she had acted very cold towards her throughout her time at Holby. That night, Jac sleeps with Jonny and later discovers that she is pregnant. A few weeks later, Jonny discovers Jac's pregnancy when he finds Mo's drawing. Although Jac is convinced she's miscarried, Jonny convinces her to take a pregnancy test. Jac finds out that she is still pregnant. Jac tells Jonny about her endometriosis and he performs an ultrasound on Jac and they see their baby for the first time. Jac has her next ultrasound scan booked at a private clinic on the other side of town. However, it is cancelled and Jonny begs the midwife at Holby City General Hospital for an appointment. Jac has her scan and it reveals everything is fine, this leads to Jonny finally announcing Jac's pregnancy publicly to the entire ward.
During Jac's 20-week scan, she finds out that her baby has congenital diaphragmatic hernia and only a 50% chance of survival after birth. Jonny tells Jac he will support her in any decision she makes. Jac decides to have an abortion. Soon after Jonny finds out about Jac's plans and tries to stop her. Unfortunately for Jonny, Jac has already left the clinic. Later, Jonny finds Jac back at the hospital and asks if she's okay. Jac then reveals she's still pregnant, confirming she didn't go through with the termination. Jac and Jonny have their first pre-natal class. The next week Jonny tells Jac that he's visited a couple with a child who has CDH. Jac gets furious, because she feels that Jonny is doing things behind her back. It is obvious though that Jac is just as scared about the future as Jonny. Jonny asks Jac to move in together and a stunned Jac unable to say anything. A couple of days later Jac throws her flat keys at Jonny and tells him to move in with her. Later, Jonny's old friend Bonnie Wallis appears on the ward. Jac gets jealous of Bonnie and threatens to fire her. Jonny, feeling sympathetic for Bonnie, returns the keys on Jac's desk. A couple of weeks later Bonnie tells Jac she and Jonny are dating and living together.
Jac goes into labour a week early and is forced to have an emergency caesarian. The baby shows signs of distress and isn't breathing right after birth. However, the doctors are able to stabilise her, and she pulls through. At first, Jac has a hard time bonding with her daughter, but after seeing Bonnie hold the baby, Jac's maternal side comes rushing to the fore. Jac decides to name her daughter Emma. Emma's birth softens Jac, but it also complicates things between Jac and Jonny. Jac wants to hire a nanny, whilst Jonny is keen on having the baby christened. As Jonny and Bonnie's relationship develops Jac gets increasingly jealous and attempts to rile Jonny. On the day of Jonny and Bonnie's wedding Jac delays Jonny by agreeing to perform surgery on Bonnie's brother in an attempt to prevent the marriage. The surgery is successful yet Jonny informs Jac he and Bonnie will be leaving after the wedding as he is unable to get Jac out of his head. Jac then kisses Jonny in an attempt to get him to stay, but after being unable to tell him she loves him, Jonny leaves to marry Bonnie. However, Bonnie dies after being hit by a truck shortly before the wedding.
Jonny blames Jac for Bonnie's death and they become locked in a custody battle for Emma. Jac's mother, Paula, is admitted to the hospital with terminal cancer. Jac pays Paula to leave and she gives the money to Jonny. After learning about Jac's past with Paula, Jonny apologises to Jac. They bond over a patient and Emma's brief hospitalisation. However, Jac then learns that Paula is staying with Jonny, despite him knowing about their past. Jac's mum health gets worse and starts going badly wrong, and Paula dies. The morning after, Jac and Emma watch the sun rise and they both meet Johnny at the hospital and Jac gives Emma to him for him to look after as she is going to Sweden. As Jac goes to the airport Johnny carries Emma asking her to reconsider. But Jac boards the plane.
Jac returns prematurely after learning of Elliot Hope's worsening health to help with the Herzig 5 project which leads to her having to take the lead halfway through the crucial operation being used to market the device. Guy then attempts to tempt Jac into taking Elliot's place; leading the Herzig 5 project and running Darwin ward. Jac is reunited with Connie by Guy for an endarterectomy procedure, pushing Jac into accepting Guy's offer of taking over Elliot's work.
After the departure of Jonny, Jac also takes extended maternity leave and ends her brief fling with hospital CEO, Guy Self. In the time that she is gone, Hanssen is reappointed CEO following the decision of Guy to step down in order to maintain his surgical timetable, and the creation of his Neuro Centre. Jac briefly returns to aid Elliot, Oliver and Zosia March in the treatment of previous hospital nurse/junior doctor Frieda Petrenko. She eventually gives Elliot the advice to follow his heart with his old flame Brigitte Nye in order to help those with tuberculosis in Pakistan.
Jac makes her full-term return as Cardiothoracic Consultant, as well as Clinical Lead, and is hellbent on getting rid of the 'deadwood' on Darwin. She arrives to find that Guy Self has taken part of Darwin for his neurosurgery patients, to her dismay. She also questions Zosia's dedication to Cardiothoracics. Zosia proves herself to Jac in theatre and Jac becomes satisfied with her team.
Agency nurse, Fran Reynolds is transferred to Darwin, having had a history in Cardiothoracics. They clash over patient Seymour Orson, a man with Asperger's syndrome refusing urgent surgery. Jac is reported for negligence by Fran to Hanssen, and compiles a file of her mortality rates in theatre. This file is shown to a patient's relative who is supposed to undergo a revolutionary and untested procedure performed by Jac. When Jac is informed of the file, and performs the surgery successfully, she confronts Fran. Jac is slapped by Fran in front of Hanssen, leading to her immediate suspension. It is later revealed that Fran and Jac had a past at St. Bartholomew's Foster Home, where a man named 'Yates' sexually assaulted the young girls. It is revealed by Fran that she was in fact assaulted by Yates, and Jac saw him do it. Jac apologises for what she did back then and promises to never turn away again, like she did before; however, security scare Fran who is hallucinating, and she falls off the roof. Jac, Guy and Hanssen all operate on her and Fran makes a speedy recovery.
Jac later begins to notice the tension between Oliver and Zosia, and worries about how their personal feelings for each other may affect their work. She offers Zosia a fake internship in Edinburgh with immediate effect for a year, forcing Oliver to tell Zosia how he truly feels. Jac eventually walks in on them both kissing in the locker room, and is proud that her plan had succeeded.
Hanssen later becomes concerned when Guy threatens his position as CEO. He asks Jac to recreate Elliot's invention of a malleable stent in order to take away funding from Guy's Neuro Centre plans. When the consultants of each ward are asked to vote between Hanssen and Guy, Jac votes in favour of Hannsen.
During the press conference regarding Jac's Digby Stent project, it is discovered that someone on Darwin has leaked details of its technology, and it has already been used in Berlin, and has failed a number of times. Jac is livid, presuming Zosia was the leak, but later finds out it was Guy in a bid for her to not receive funding.
When new consultant, Matteo Rossini arrives, he develops an instant attraction to Jac. However, it is discovered that he is the one that plagiarised Jac's research, and made her stent with Guy's leaked knowledge. Jac learns she has an ovearian cyst, but refuses to have an operation to remove it. Shortly before performing a life-saving procedure on Jonny's brother Alastair, Jac collapses and has to undergo urgent surgery performed by Derwood Thompson and Matteo. Matteo and Jac share a kiss in her office. He later asks her to accompany him to Italy and Mo persuades her to go. Jac learns Matteo is married and their relationship ends.
Jac is demoted from her role as clinical lead of Darwin by Hanssen, who has been keeping a log on her misconducts. She had earlier performed unauthorised surgery on Fran Reynolds who was technically Matteo's patient after Jac passed on treating her, however, Fran pressured Jac into performing the surgery with threats of revealing the childhood abuse. Jac asks Jasmine Burrows to assist her in surgery in an attempt to keep it a secret from Matteo and others. Matteo found out during the surgery and chastised Jac before reporting to Hanssen. Jac later learns Jasmine is her younger sister and has her removed from Darwin.
Jac, along with Oliver and Raf di Lucca, is shot by Fredrik Johansson, Hanssen's son. She is found by Sacha and John Gaskell, who help to save her life. Jac experiences a lot of pain following the shooting, and agrees to let John operate on her to reduce her scar tissue and insert an implant containing stem cells. A month later, Jac develops an infection and collapses in her office. She is then placed into an induced coma. Once she wakes up, she has to go to theatre where John and Roxanna MacMillan discover that she has sepsis. As they treat her, Jac goes into peri-arrest. Roxanna proceeds to go to theatre, despite Gaskell stating that Jac has just about got through the other operation. Jac goes into cardiac arrest on the table and nearly dies, but Roxanna, Hanssen and Meena Chowdhury manage to save her.

Development

Casting and introduction

Prior to her casting, Marcel had appeared in Holby City in an unrelated role, as a drug addict named Elinor. After joining the cast of Holby City as Jac, Marcel signed a three-year contract with the drama, securing her on the show until 2008. Marcel was introduced to the series alongside Luke Roberts and Tom Chambers, who portray cardiothoracic registrars Joseph Byrne and Sam Strachan, respectively. Jac is introduced during the episode titled "Bird on a Wire", which was broadcast on 22 November 2005. A writer from Inside Soap reported that Jac arrives at the hospital determined to impress consultant Ric Griffin. She offers to help on a double amputation procedure and insists that Ric will be so impressed he will offer her a permanent role at Holby. Medical trainee Dean West accidentally cuts Ric's hand and this puts him in a bad mood. Jac has to work harder to impress Ric as he insists he no longer needs her help. In two series twelve episodes, Cydney Dubavin-Hands played a teenage Jac in flashback scenes.
Writers soon developed a rivalry between Jac and fellow registrar Diane Lloyd. The story sees the pair fight for the role of locum consultant, which Diane goes onto secure. A writer from the Liverpool Echo stated that Jac took credit for work Diane had done. They added "Diane and Jac's working relationship hasn't exactly been an easy one to date, and it doesn't look as if it's going to improve". The pair later argue over patient care. When a paroled murderer is admitted to Darwin ward, they disagree on the cause of his pain. Jac decides to take over the case and orders x-rays to confirm her diagnosis. She goes to see consultant Dan Clifford and complains about having to work alongside Diane. He sides with Diane and throws Jac's diagnosis in the bin. When Diane realises that Jac was correct about the man's condition she is forced to apologise.

Characterisation

According to the official Holby City website, Jac is "strong-minded" and forthright. Professionally, she is a highly ambitious "political player", determined to become a consultant and attain recognition for her surgical skills. She is willing to hurt others to achieve her goals, and has a "professional façade", developed as a result of pursuing a career in a male-dominated field. A BBC Online reporter thought that Jac's "determination to be brilliant might just kill her". Jac demonstrates a willingness to flout rules and endanger patients to advance her own career. Marcel liked Jac's original characterisation of a woman "who would gladly sell her soul to the devil in exchange for a better job". Bob Barrett, who portrays Sacha Levy in the drama, dubbed the character "Ms Darwin" after she is promoted to clinical lead of cardiothoracic ward, Darwin. Outside of work, Jac is "charming and hugely sociable". Placed in foster care by her mother aged twelve, she finds it difficult to form relationships due to an inability to commit and "let herself go". Barrett was inspired by the exploration of Jac's characterisation and backstory when exploring his own character.
Shortly after joining the cast, producers spoke to Marcel about turning the character of Jac into "a massive bitch", which excited her. The actress explained in June 2018 that Jac's nastier personality combined with the stories written for is the reason she has remained on Holby City. In 2008, Jac had firmly been established as a "rude" and "bitchy" character. Marcel told an Inside Soap reporter that "she's too honest for my liking. There's a fine line between being honest and rude. I'd want to hit her over the head!" Scriptwriter Patrick Homes found it easy to write stories for Jac due to her "defined" characterisation. Marcel reflected on her character's characterisation in 2015, stating that she enjoys how Jac "says the things that people wouldn't normally say, or would at least think about first". Three years later, the actress opined that Jac is more gentle than she was upon her introduction. She hoped that the character would toughen up, but expected her to experience some painful stories first.
Though Jac rarely falls in love, she is not averse to using sexual manipulation to achieve her goals, for example she has had romances with several of her colleagues; consultant Nick Jordan, who she let "too close and was burned", and foundation doctor Oliver Valentine. Noting this trait, television critic Jim Shelley described Jac as a "man-eating android".
In 2011, writers planned to rejuvenate Jac's nasty persona. Producers created a medical story which leaves Jac conflicted in the face of treating an infant patient. When Jac is introduced to baby Freya who requires heart surgery, she behaves in her usual nasty manner. When Freya's mother abandons her, Jac bonds with the baby. Marcel told Katy Moon from Inside Soap that Jac relates to Freya because her mother also abandoned her. Jac operates on Freya and she nearly dies during the procedure. She said that "Jac's becoming attached" and when Jac saves her life "that's when the real bond develops". Marcel explained that Freya "has a big impact" on Jac and it was the start of a long-running story in which her character changes.
In 2019, Marcel assessed that Jac is still mean but also does "so much good for people" via her job. She explained that Jac has had a "hard life and come out the other side." She added that Jac is a fighter because she carries on through the bad and wanted viewers to be inspired by Jac's driven persona.

Relationship with Joseph Byrne

Producers paired Jac with fellow registrar Joseph. Jac originally only slept with Joseph in a bid to further her career. She had previously been involved in an affair with Joseph's father Lord Byrne. He later moves on with ward sister Faye Morton, which causes a feud. Jac and Joseph later sleep together and tricks Joseph into believing that she is pregnant with his child. When Faye discovers the truth she breaks-up with him. Kensit said that "he's done the most unforgivable thing". Joseph manages to convince Faye to marry him, but she soon takes a romantic interest in Linden Cullen. Jac continues to interfere in Joseph's relationship, becoming wary of Faye and Linden and Kensit stated that Jac had the right to be suspicious.
Jac and Joseph briefly reunited prior to Roberts' departure from the series. Marcel told Inside Soap's Moon that "Jac will always love Joseph." When Roberts left he made Marcel a promise that he would return to the show if she ever chose to leave, so that Jac and Joseph could leave together. Marcel later assessed that Jac gave up on a ready made family with Joseph and Harry. Roberts told Victoria Wilson from What's on TV that Jac and Joseph's relationship was "tumultuous" and "very passionate" despite Joseph's treatment of Jac. He concluded that Jac and Joseph class each other as the "one that got away".
In 2019, Roberts returned to the show for one episode as Joseph. Marcel was surprised that Roberts agreed to return having previously stating that he would only return amid a departure for Jac. Marcel told Laura Jayne-Tyler from Inside Soap that even after ten years, Joseph is still "the love of her life". This is because they parted on good terms and Jac has constantly compared subsequent partners with Joseph. He returns with Faye and Marcel believed that Jac seeing them together again "is one of the most difficult things she has ever had to do." Joseph is at the hospital to support Faye through a heart transplant. Roberts stated that Joseph's heart has always belonged to Jac. He described it as "an eternal love that will never go away." So Joseph is on a "rescue mission" to save Faye, but ultimately "Jac's magnetic pull hasn't weakened" and they end up revisiting old feelings. He later told Sophie Dainty from Digital Spy that "he's so drawn to her – he is almost looking for an excuse. Otherwise, why is he there? He's nervous and it's a collection of emotions. He doesn't know what to do with it."

Assault and murder investigation

In September 2007, writers made Jac the victim of an attempted sexual assault. In the episode titled "Friends Reunited", Alan Clooney is admitted to the Darwin ward following a car accident. He is instantly attracted to Jac and enjoys receiving medical attention from her. Marcel told Katy Moon from Inside Soap that Jac only gives Alan "professional attention" but he "gets the wrong idea". Jac is preoccupied with another patient Graham Fenton, whom she recognises from her school days. This aggravates Alan and makes him jealous. When Graham reveals that he now works for a US pharmaceutical company, she forges a romantic interest in him. Marcel explained that Jac used to bully Graham for being overweight and suffering from acne. He is now good looking and successful, and "in Jac's mind, the fact that he works for a pharmaceutical company in America also represents an opportunity for her to further her career." Graham is fooling Jac to enact revenge for the bullying ordeal she inflicted on him. When she meets with him for a date, he kisses her and reveals he is married with children. Marcel said that Graham "just wanted to embarrass her" in public.
Alan witnesses the incident and takes an opportunity to goad Jac. He speaks to her "menacingly" and attacks her until she loses consciousness, then drags her into bushes. Unbeknownst to Jac, registrar Lola Griffin had been watching Alan around Jac and suspected he was a rapist. Lola telephones Jac when she notices Jac and Alan are both missing from the ward. The ring tone rouses Jac into consciousness and she tries to fight of Alan. He tries to sexually assault her but Lola arrives in time and hits Alan with a metal bar. The attack leaves Jac at her "lowest ebb" and Marcel said that her character "is sickened" with Lola because she knew Alan posed a serious threat.
In March 2008, Alan is reintroduced into the show and is later found stabbed to death. This story crossed over into the show's sister series HolbyBlue. The episode focuses on the murder investigation and police interviews conducted with Holby City characters. Jac is arrested on suspicion of murder, having earlier threatened to kill Alan in-front of her colleagues. Marcel told an Inside Soap reporter that Jac "finds it hard" because the evidence suggests she killed him, adding that "she has no credible alibi and her fingerprints are on the murder weapon."
Jac pleads her innocence when she is presented with the evidence. The actress sympathised with Jac because "she fully believes in her abilities as a surgeon and wouldn't jeopardise that." When the police interview Joseph, he does not defend Jac and claims that she is capable of murder. Marcel said that Jac should be shocked by Joseph's statement but "she has a history with him, so he probably believes that she's capable of anything." Marcel told a BBC Online reporter that fans would "love the storyline" because it features "Jac getting her ". She concluded that "you get to see another side to Jac in this episode – a side that she never shows in Holby City – so that should be really interesting to fans of the show." Marcel had a "fantastic time" working on the HolbyBlue set and liked how different the set worked in comparison to the Holby City one.

Feud with Faye Morton

Writers developed a feud with ward sister Faye which has dramatic consequences for Jac. She is jealous that Faye has begun a relationship with Joseph. Maeve Quigley from Daily Mirror observed that Faye had become Jac's enemy by February 2008, adding that her "main hobby is scoring points off Faye." When Faye takes time off work for a dentist appointment, Jac becomes suspicious. Faye is actually attending the police exhumation of her ex-husband's dead body. Jac realises that Faye has lied about her whereabouts when she witnesses her with the police. Jac visits vicar Kevin Mathers who reveals that he "can see the good" in her. This prompts Jac to hatch a scheme and creates a new friendly persona. She soon covers for Faye to keep her secret hidden and takes the blame for a small fire ward sister Kyla Tyson causes.
Jac carries on pretending to be Faye's friend for months until a culmination to the plot aired in June 2008. Faye's stepson Carl Hewson arrives at the hospital demanding money to pay off loan sharks. He blackmails Faye and Jac spots an opportunity to sabotage things. Marcel told Moon that "Jac appears to help Faye out - but being the 'nice' person she is, Jac's looking to trip her up." She convinces Joseph and Faye to not give Carl more money, which results in the loan sharks attacking Carl. He is taken to an operating theatre where Jac fails to save his life. Marcel explained that both Joseph and Faye hold Jac responsible for Carl's death. This makes Jac more determined to expose Faye as a liar. Marcel said that Jac still loves Joseph and wants him back because "in her eyes Faye has stolen him from her." Jac becomes suspicious of secretive Faye as she gets into a taxi. Jac follows the vehicle on her motorcycle and tracks Faye down to a nursing home. Faye's secret son is being cared for in the home and Jac cannot wait to tell Joseph the truth.
Marcel said that Jac is determined to expose Faye and speeds off on her motorbike. Jac's recklessness has severe consequences when she crashes and is hurled from her motorbike. Off-screen Marcel believed that motorbikes are unsafe. She used to ride them but ceased after she had accidents and some of her friends died in separate motorbike crashes. This meant that the scenes required a stunt double to portray the crash scenes. To add realism, Marcel was attached to the back of a moving lorry and filmed to give the impression of her riding the motorbike. Marcel explained that after the stunt double had finished their role, "it's my crumpled body lying on the ground at the end of the episode." The actress concluded that Jac is taken to hospital and it is "touch-and-go whether she'll pull through".
Joseph and Faye separate following her affair with Linden. This leaves Jac and Joseph free to rekindle their romance. Faye gives birth to his child Harry, while detained in a mental health facility. The events force Joseph to break-up with Jac. But when Faye refuses to associate with Joseph, he apologises to Jac and they get back together.

Friendship with Sacha Levy

Then-script editor Simon Harper suggested pairing Jac with registrar Sacha Levy following his introduction as the characters have contrasting personalities. On the actors' first day working together, they filmed two more scenes than planned as they were working so quickly. The characters remained paired together for six months. Barrett thought the characters were friends because with Jac, Sacha can " straight through what everyone else struggles with" and understands that Jac has "the greatest heart". Likewise, with Sacha, Jac speaks to him in a different manner to everyone else, and together, they trust each other a lot. Marcel believed that Jac and Sacha should be romantically involved because "they are like yin and yang". She added that it was "a shame" Sacha loved ward sister Chrissie Williams instead. The actress later spoke again of her wish for the pair to be together. She said that they would "make such a hilarious couple" but did not think it would ever happen. Sacha and Chrissie later prepare to marry, but Jac notices that Chrissie is having second thoughts. She warns Chrissie not to hurt Sacha and Hobley explained that Jac believes "if anyone deserves to be happy more than anyone she's ever met, it's Sacha".
Marcel and Barrett formed an idea that Jac and Sacha should live together in an unseen flat with viewers only seeing the characters speaking about home life. In 2018, Sacha is featured in an issue-led story about depression and male mental health. Jac becomes involved in Sacha's rehabilitation process after he tries to kill himself. Barrett dubbed Jac "Sacha's guardian angel" and she is saddened to hear about his battle, but is also "furious" that he did not speak to her or his former partner, Essie Harrison. Jac then comforts Sacha and tells him that he will move into her home. Barrett explained that this would aid Sacha's recovery, but not complete it.

Feud with Sahira Shah

In 2011, producers introduced actress Laila Rouass as registrar Sahira Shah and another sparring partner for Jac. Writers pitted the characters against each other via a story where they compete for the same consultancy role. Sahira is portrayed as a talented and able surgeon who rivals Jac. Marcel explained that Jac's professional feuds had traditionally been against male characters, but Jac now had to face a female who "has it all". Sahira has a husband and children but still manages to excel in her career. This provokes Jac because she will not let "someone like that beat her." Jac believes the only reason she secured a job at Holby City hospital is because she is an old friend of CEO Henrik Hanssen.
When a patient dies suddenly during an operation carried out by Jac, Sahira helps her find evidence about what has happened. Marcel said that this makes Jac wary because she "fears it's an opportunity for Sahira to stitch her up." Marcel noted that Jac is not opposed to using Sahira for "team work" to achieve "great surgery". They cooperate and discover that the patient had been involved in a suicide pact. She caused a motorbike crash and ingested blood thinning chemicals to sabotage any surgical efforts to save her life.
She told a Daily Mirror journalist that Jac and Sahira have "a tense relationship" filled with "lots of one liners" and is kept is solely work related. Rouass thought that the rivalry never got "too serious" and the "catty comments" gave the story a "fun element". She told a reporter from the Bath Chronicle that "they're both very competitive and focused and both want the same outcome but they do it in different ways and have different approaches to their job." Rouass added that the characters are both "exceptional" at work and actually respect one another. Rouass told Daniel Kilkelly of Digital Spy that while Jac and Sahira shared a "silent respect" over work, the characters are "completely different". Sahira "kills people with kindness" rather than being sly. She added that Jac makes Sahira feel "threatened".

Jonny Maconie and pregnancy

While attending a people skills course, Jac has a one-night stand with Jonny Maconie, who is later introduced to the series as a regular character. Jac is under the impression that Jonny is a neurosurgeon, so she is surprised to learn that he is really a nurse and about to start working at Holby as part of the transplant team. Thompson said Jonny is "like the kryptonite to Jac's super ice maiden." He is not intimidated by Jac and she does not know what to make of him, leading to a "fiery" relationship. Jac and Jonny break up after a few months, but Thomson believed there was unfinished business between them. He explained, "She's messed with his head, and he wants to fix her. He wants to prove to her that it's all right to be warm and love people." Jac and Jonny briefly get back together, however, when Jac learns that her former boyfriend Joseph Byrne is getting married, she initially takes her frustration out on Jonny and later has sex with paediatrician Sean Dolan. Jac leaves for Japan to study some new medical techniques, and on her return she tells Jonny that she loves him. Thomson said that the declaration and her show of commitment "blows Jonny's mind and takes their relationship in a new direction."
While performing a preliminary procedure on a patient, Jac experiences some pain and Jonny worries that it could be related to her kidney. Knowing that she donated one to her estranged mother, he is worried that she could be in danger if the remaining one fails. Jac orders some tests, but they come back clear. She is later forced to abandon her patient during surgery, as she is overcome by pain again and has to lie down. Jac meets with her consultant obstetrician and gynaecologist Derwood Thompson, who informs her that she has endometriosis, a condition which greatly reduces her chances of conceiving. Jac keeps her diagnosis from Jonny, knowing that he wants a family, while he surpsises her by asking her to move in with him. Thomson pointed out that it was not unusual for Jac to hide something from Jonny, because she had built up many defences over the years when she felt scared. A "bitter row" breaks out between Jac and Jonny over her treatment of Tara Lo, who was affected by her brain tumour while assisting Jac during surgery. Jonny disagrees with Jac's decision to ask Tara to leave the theatre, and she ends up slapping him across the face. Jonny then ends their relationship, leaving Jac feeling isolated.
Following Tara's funeral, Jac and Jonny have a one-night stand, but they both tell Mo Effanga separately that they do not plan on getting back together. Jac later learns that she is pregnant with Jonny's baby. When Jonny finds out that Jac told Mo about the baby before him, he confronts Jac, who is overcome with "uncharacteristic" emotion and bursts into tears. Jonny later performs an ultrasound scan on Jac and they get to see their baby for the first time. During Jac's 20-week scan, she and Jonny are informed that their baby has a congenital diaphragmatic hernia, meaning it has a 50% chance of survival after birth. They also told that further tests need to be carried out, before they can talk about their options.

Temporary departure

On 11 August 2014, it was announced that Marcel was pregnant with her first child and that Jac would take a break from Holby City. Jac exits in the seventeenth series episode "Go the Distance", originally broadcast on 14 April 2015, after reuniting with Jonny. Thomson also decided to leave the show to return to theatrical projects. Thomson explained that viewers wished for a "happy ending" for Jac, which happens through her and Jonny's departure. He thought that it was a perfect conclusion to Jac and Jonny's relationship as they establish their family life. The actor added that Jac and Jonny have realised "what they mean to each other". Marcel and Thomson made a guest appearance together in the series 17 episode "Spiral Staircases", originally broadcast on 23 June 2015.
Before Marcel took maternity leave, her co-star, Paul Bradley, decided to leave his role as Elliot Hope. Marcel asked producers to return for his exit episode before she left and producers agreed as they also shared an interest in arranging this. A show trailer previewing Jac's appearance was released on 16 September 2015, and the appearance features in the series 17 episode "At First I Was Afraid", originally broadcast on 22 September 2015. Jac mentions that she and Jonny have separated. Holby City series producer Simon Harper clarified that their split was "perfectly amiable" and they are sharing parental responsibility of Emma. He also pointed out even though the characters tried a relationship, their alternative personalities meant it would not succeed. Marcel expanded on the breakdown of the relationship, stating that Jac dislikes how Jonny did not aspire to be "anything other than a nurse". The actress opined that Jac is better as a single woman. She also added that the failure of the relationship allows Jac to "toughen up" and return to her meaner personality.
Harper confirmed in October 2015 that Jac would return during the following month, and Jac returns in the eighteenth series episode "A Delicate Truth", originally broadcast on 24 November 2015. Harper revealed that Jac would return "with a bang" as she reclaims her status as the head of Darwin ward and reassesses the ward's structure and staffing. Marcel added, "She's in full-on Jac mode now and demands to know exactly what's going on." Jac immediately decides to make her junior doctors, Oliver and Zosia March, prove themselves by handing them bad jobs. Marcel explained that this method works and gives Jac the best doctors on her cardiothoracic team. Following her return, there is more emphasis on Jac's bitchy personality, something which Marcel also wanted to reinforce. She thought that the character had proved popular and remained on the drama due to her villainous characterisation. Marcel struggled to readjust to the schedule of working on Holby City after being on maternity leave.

Matteo Rossini

Christian Vit was cast as Matteo Rossini, a cardiothoracic consultant, in 2016. Matteo was introduced as a rival and possible love interest for Jac. Jac instantly dislikes Matteo and clashes with him when he begins to work on her patient. Vit explained that Matteo would prefer to challenge Jac's behaviour than leave her alone. Jac then discovers that Matteo was in the team who stole her Stent research, infuriating her. Matteo tells Jac that he did not intend to "steal" her project, but she does not believe him and claims one of Matteo's ideas for their patient. Vit pointed out that Matteo "immediately realises what kind of character Jac is", but is also fascinated by her. Writers placed the characters in a "cat and mouse" game as Matteo tries to impress Jac with his "Italian charm". Vit commented, "With Jac, he knows he'll always be on thin ice!"

Fletch

Holby City series producer Kate Hall announced plans in August 2017 to pair Jac with director of nursing Adrian "Fletch" Fletcher. Marcel and Walkinshaw previously portrayed a couple in The Bill and were pleased to work with each other. When Walkinshaw joined Holby City, writers inserted a reference to the actors' history in an episode. Marcel had previously called for Walkinshaw to be introduced into the show in 2011, so Jac could have a romance with a character he played. Despite this, when Jac and Fletch were paired together, the actors were not pleased as they did not feel the characters were well-suited. Hall wanted to pair the characters because she liked the connection between Marcel and Walkinshaw, calling it "palpable", "delicious and electric". She compared the matching to characters Maddie Hayes and David Addison in Moonlighting and Peter Joshua and Reggie Lampert in Charade. Marcel enjoyed playing the Moonlighting comparison, but opined that Walkinshaw is the Maddie to her David.
Walkinshaw identified how Jac and Fletch have contrasting personalities and opined that the pairing would be "interesting" as Fletch is not afraid to challenge Jac's formidable behaviour. He added that Fletch would not be "intimidated" by Jac. Walkinshaw explained that this is refreshing for Jac as she is accustomed to "having a man standing opposite her desk, to attention, while she's sitting telling them off and letting them know exactly how the land lies." The actor added that although Fletch finds Jac scary, he is not afraid to challenge how she speaks to him or his nursing staff, reminding her that she is not their boss. He also looked forward to filming scenes where they clash, and scenes where they bond.
The story begins in the nineteenth series when Jac assists Fletch with a patient. The story was filmed on the AAU set, where Fletch is based, which Marcel enjoyed as she rarely films away from Darwin ward. Jac later uncharacteristically takes "her guard down" around Fletch and grieves for her recently-murdered half-sister, Jasmine Burrows, which strengthens her bond with Fletch. The characters continue to bond as Fletch moves to Darwin ward and they work together more. On their bond, a What's on TV reporter noted, "it's obvious Jac has eyes for Fletch". Marcel took a three-month break from the drama in 2018, pausing the budding relationship. When Jac returns, it is apparent that Fletch has missed her, which Marcel liked. The actress thought it was clear that the characters had strong feelings for each other. Jac does not return for a relationship with Fletch, which disappoints him. However, he is still supportive when she prepares for her operation.

Shooting and recovery problems

After the shooting Jac takes time off work to recuperate from her injuries. While she is away scar tissue forms and begins to cause Jac more pain. Professor John Gaskell recommends that Jac takes part in his dodgy stem-cell treatment trial and he will perform the operation. Marcel told from Jayne-Tyler from Inside Soap that upon Jac's return "she seems healthy and fit when she returns, but she's masking quite a lot of pain." Jac "thought long and hard" about her options and she decides that Gaskell's plan is her best chance. Marcel described portraying Jac's difficult year of recovery as exhausting and a "tough year". She explained that she would often take Jac's emotional baggage home with her as she learned lines.

Mental health

Series producer Jane Wallbank confirmed in August 2019 that Jac would be the focus on a new story about mental health. She explained that Jac's work and home lives would place her under pressure, leading her to struggle, especially as she tries to prioritise Emma. The story coincides with the guest returns of Joseph and Elliot. Wallbank told Dainty that she wanted their returns to impact Jac's story. Joseph returns at a point when Jac begins to struggle and Elliot's return occurs as the plot climaxes. She also praised Marcel's performances as Jac as "heart wrenching", and confirmed that the story would feature on-location scenes.

Other appearances

Alongside her appearances in Holby City, Marcel has played Jac in the show's sister shows, HolbyBlue and Casualty. Jac appears in the opening episode of HolbyBlue second series, first broadcast in 2008. Marcel first appears in Casualty for one episode, originally aired in February 2016, during its thirty series to coincide with the appearance of Sam Strachan. She later makes cameo appearances in Casualty thirtieth anniversary episode, originally broadcast in August 2016, and an episode of the thirty-first series, originally broadcast in September 2016.
Kate Hall, the then-series producer, confirmed in August 2017 that Marcel would reprise her role in Casualty for two episodes, and Jac appears in two episodes of series 32, first broadcast in February 2018, where she is involved in a storyline with Ethan Hardy. Producers of Holby City and Casualty planned a crossover event for the shows in 2018, prominently featuring Jac and Casualty character Connie Beauchamp, who formerly appeared in Holby City. Executive producer Simon Harper explained that both casts would be featured "striving heroically against the odds in two episodes of pure, nail-biting, taut, emotional medical drama." The episode was filmed in November 2018 and first broadcast in March 2019.

Reception

Marcel has been nominated for several awards for her portrayal of Jac. She received consecutive "Best Actress" longlist nominations at the 2009 and 2010 TV Choice Awards, and later in 2010, was longlisted for the "Best Drama Performance" accolade at the National Television Awards, alongside her co-star Roberts. In August 2017, Marcel was longlisted for Best Drama Star at the Inside Soap Awards, while the storyline featuring the death of Jac's half-sister Jasmine Burrows was longlisted for Best Drama Storyline. Neither nomination progressed to the viewer-voted shortlist. For her portrayal of Jac, Marcel was nominated for Best Soap Actor at the 2018 Digital Spy Reader Awards; she came in seventh place with 6.4% of the total votes.
An Inside Soap reporter's first impressions of Jac were that she is a "leather-clad biker" and "feisty surgeon". Jac became so popular that viewers created a fan site for the character. In 2008, Marcel declared "it's sweet that they love Jac enough to dedicate a website to her - considering what a bitch she is!" Katy Moon of Inside Soap said "over the years, Jac Naylor has had many adversaries", "is used to playing dirty" and "is known for her ruthless streak." Her colleague, Laura-Jayne Tyler, described the character as "fearsome". Series producer Kate Hall noticed that non-romantic pairings, such as Jac and Sacha, were more popular than romantic pairings. Victoria Wilson from What's on TV branded Jac the show's "resident ice queen".
Marcel's co-stars praised her performances and acting techniques as Jac in interviews with Sue Haasler for the book Holby City: Behind the Screen. David Ajao called Marcel a "professional" and said how her work as Jac had inspired him. Eleanor Fanyinka said that Marcel's "stillness and her power is phenomenal".