Characterisation The actress created character traits inspired by people she knew. She also recognises aspects of her own personality in Zosia's persona. Zosia does not suffer fools and behaves in a "sexually voracious" manner. Arfwedson told Benita Adesuyan (
Daily Express) that her character "likes to pin men down then discard them as she wishes. She’s very determined and ambitious, and she doesn’t really care about upsetting people.” Arfwedson rose to the challenge of portraying lengthy medical dialogue. She explained that because Zosia is "so bright and so good at what she does", she wanted Zosia to sound as convincing as possible when discussing patient cases. With a cool and collected manner she does not suffer fools gladly. Arfwedson attributes a "no filter" complex - she does not think about what she says or how other perceive her. In turn this paints her as unfeeling, "very matter of fact" and obsessive about work. The show developed Zosia and Dom into a "best friend" partnership. When Dominic creates a false story of how his mother died, Arthur decides to expose him as a liar. But the truth does not faze Zosia as she aspires to be a psychiatrist, Dominic being a sociopath only makes him more interesting. The show's series producer Simon Harper announced that viewers would witness a "new side" to Zosia. The change comes following the arrival of
Guy Self (
John Michie) and it becomes clear that the "driven nature" is a family trait. Guy's arrival also makes Zosia's life unstable. Harper explained that "So far she's been very much in control and is very alpha for a junior doctor, but we're going to learn that there's more complexity and vulnerability behind the polished exterior." Michie labeled the relationship between Zosia and Guy "strange and dyfunctional". Following the death of Zosia's mother, Guy began drinking and had affairs. This distanced the pair and Guy chose to come to Holby City not only to help his career. Michie said "he wants to retrieve the love of his daughter". This task is made extremely difficult because "she blames him for everything thats wrong in her life." When Guy tries to make amends with Zosia she rejects him and makes it clear she only wants a professional relationship with him. But her animosity towards Guy begins to affect her career progression. The pair do develop some level of respect. As seen in a storyline where they bond over the treatment of a patient named Beth Forbes (Lois Chimimba). Zosia misdiagnoses Beth and Guy realises she has a brain aneurysm and tries to safe her life. However, an
Inside Soap columnist reported that Zosia was only taking "baby steps" in her approach to repair their "damaged relationship". But Zosia's rude temperament soon gets her into trouble on the anniversary of her mother's death. Zosia is thrown off the Keller ward after confronting a patient's relative, Owen Saunders (Joe Claflin). She is then "hell-bent on drowning her sorrows". But Owen follows her to the bar and spikes her drink with GHB. Zosia is aware of is this and forces him to drink it causing him to fit.
Affair with Jesse Law In April 2014, a new Consultant Anaesthetist
Jesse Law is hired on Keller Ward. Jesse is an old friend of Guy's and is already acquainted with Zosia.
Don Gilet who plays the character told Katy Moon from
Inside Soap that Zosia calls him "Uncle Jesse" and this causes others to tease him. A reporter from the
Grimsby Telegraph reported that the inclusion of patient Lindsey Kendal (
Claire Sweeney) in Zosia's storyline would help develop a romance story with Jesse. Zosia is accused of not empathising with patients and is referred to as a "grumpy
Kate Adie" on a feedback form. Jesse teases her over the event and suggests working on Lindsey's case to develop her rapport with patients. Arfwedson told a ''What's on TV'' reporter that Zosia is fond of Jesse because of his history with Guy. A fondness that develops into a flirtation. Zosia is "terribly efficient" getting the job done which causes her failure to empathise. Her bossy attitude means people are "terrified" of her. But Jesse is the only character within the show able to tease and amuse her. The pair continue their affair in secret but it soon becomes problematic. Arfwedson assessed that Guy could not accept Zosia and Jesse because the latter "is such a player" and has been sleeping with his daughter.
Bipolar disorder One of the characters most prominent stories has been her battle with
Bipolar disorder. The story begins on-screen when Zosia behaves recklessly following her break-up with Jesse. She treats a cancer patient who reminds her of her dead mother. The experience leaves Zosia upset and she turns to recreational drugs to "numb" her pain. Arfwedson branded the scenes "very high octane and very exciting". She likened the entire episode to a "mini-movie" and where Zosia is sweaty, greasy haired and looks bad. The actress concluded that personally it was "terrifying" to watch. Her behaviour continues, Arfwedson observed the character "spiral out of control" as she puts patients lives at risk, takes drugs and nearly burned down her flat. When she is discharged he ignores a psychiatrist's advice that Zosia undergoes more intense treatment. Zosia insists that she is of sound mind to return to work. As the CEO, Guy is able to let her return and even invites her to work alongside him in the operating theatre. But while in there he notices that Zosia is still unwell. Zosia begins to take a mood-stabilizing drug called Lithium and some that die from the illness refuse to take the drug. Arthur is diagnosed with terminal cancer. Arfwedson said that her fictional counterpart cannot cope with his illness. She feels like a "spectator" watching on and unable to solve his problems. It really affects Zosia and she keeps her feelings hidden because she is so scared about Arthur's health. Having lost her mother and being unaware how advanced her cancer was, Zosia feels unequipped to deal with his prognosis and does not support him enough. Arthur's condition deteriorates and Zosia begins to unravel and it affects her work. The actress explained that Zosia is left fearing Arthur's illness will trigger a bipolar episode. She worries that if she fully acknowledges her best friend's condition then "she'll spiral out of control." Ostlere said that his character's death would create an interesting story for Zosia.
Relationship with Oliver Valentine Zosia begins working with
specialist registrar Oliver Valentine (
James Anderson). A writer from
Inside Soap assessed that there was a "mutual hatred" between the characters from the moment they met. They disagree over patient care and clash during surgery. The duo have to set aside their difference to avoid compromising patient's treatment. Despite their initial dislike the two character share more screen time and bond. They develop banter and a fun working relationship. A new psychiatrist, Sebastian Coulter (
Hadley Fraser), arrives at the hospital and asks Zosia for a date. She agrees and they continue to spend time together. This creates a "love triangle" scenario and Oliver and Seb compete for her attention.
Holby City producer Simon Harper told Daniel Kilkelly from
Digital Spy that Zosia and Oliver have a "delicious chemistry". When Zosia is named in the local newspaper as having bipolar disorder she is eager to prove it will not affect her surgical abilities. Zosia decides to give Oliver another chance. She tracks him down to a bar but finds him drunken and kissing staff nurse
Cara Martinez (
Niamh Walsh). The actress described Zosia's shock "As far as Zosia's concerned that really is the end for them. It’s very sad." The pair later reunite and marry in the episode titled "
Veil of Tears – Part One". They face a number of issues including Zosia's disapproving father Guy, who she bans from the ceremony for trying to sabotage things. He then gets drunk and smashes the guest table and wedding cake inside their reception room.
Departure and returns On 10 September 2017, Arfwedson announced her departure from
Holby City on her social media account, after appearing in the serial for four years. She made her final appearance as Zosia on 26 September. Of her decision to leave, Arfwedson said "It's been a real honour to play Zosia and to work at Holby. I have loved playing her with all her ups and downs, battles with her mental health and close relationships. She has been inspiring and challenging in equal measure. A truly wonderful part to play." She returned on 2 January 2018. On 19 September 2018, it was announced that Arfwedson had agreed to reprise the role of Zosia for an extended guest appearance. ''Holby City's'' Executive Producer Simon Harper said that the character was returning because of "popular demand" from the show's viewers. She is scheduled to return during February 2019. When Zosia returns to the ward she has a secret and feels lonely. Arfwedson told Laura-Jayne Tyler from
Inside Soap that Zosia has worked hard at Yale but feels isolated and alone in the United States. It emerges that Zosia's secret is that she is expecting a baby and five months pregnant when she returns. The character departed two months later in the
series 21 episode "North and South", originally broadcast on 16 April 2019. Having been secretive about her pregnancy and avoiding having baby scans, Zosia admits that she plans to have the baby adopted. However, when she suffers a fall, Zosia has a scan confirming the baby's good health. In the aftermath, Zosia decides to return to America to raise the child and it emerges that Oliver is the father of the baby. As she leaves, Zosia speaks to Oliver, hinting that the couple could reconcile. Zosia appears in a video call with Oliver as he plans to join her and their son, Arthur, in America. but Zosia's identity was not revealed until transmission. ==Reception==