Dylan Keogh is a fictional character from the BBC medical drama Casualty, played by William Beck. He first appeared in the twenty-fifth series episode "Only Human", broadcast on 12 March 2011. The character was introduced as a replacement for fellow emergency medicine doctor Ruth Winters (Georgia Taylor). Beck had briefly attended medical school before becoming an actor, and he felt the role was right for him. Dylan is a Consultant in emergency medicine and a member of Holby City Hospital's emergency department staff. Since the departure of Charlie Fairhead in 2024, Dylan has been the longest-serving character on the show.
Upon joining the cast, Beck was told by the producers that Dylan should not smile. Beck felt that he understood where Dylan was coming from. Dylan enjoys his work and likes to take on the more unusual cases and medical mysteries. He lives alone on a houseboat with his dog, Dervla, until her death. During his time in the ED, Dylan has developed strong friendships with Zoe Hanna (Sunetra Sarker) and Lofty Chiltern (Lee Mead).
Dylan's estranged wife Sam Nicholls (Charlotte Salt) was introduced to the ED in late 2011. They have a troubled relationship, which deteriorates further once Sam files for divorce and it began to affect their work. Dylan has hope that they might reconcile, until he learns Sam is dating Tom Kent (Oliver Coleman). The character departed the show in late 2012, after he struggled to be around Sam, whom he still loved. Two years later, in 2014, Beck reprised the role and expressed his excitement about playing Dylan again. Dylan briefly takes up the position of acting clinical lead, and tries to improve standards in the ED, but he was challenged by the job's demands.
In August 2015, producers introduced Dylan's estranged father, Brian (Matthew Marsh), which leading to further exploration of his background. Dylan has a poor relationship with Brian and his mental health suffered when they clashed. He is later diagnosed with obsessive–compulsive disorder. The show's story producer wanted to challenge the character with the condition and show how it affected him personally. Later storylines have seen the character accused of sexual harassment, smuggling a refugee into the country, and struggling with alcoholism.
Casting Actor William Beck joined the cast of Casualty as regular character Dylan Keogh during the twenty-fifth series. He was introduced as a replacement for fellow emergency medicine doctor Ruth Winters (Georgia Taylor), who had been admitted to a psychiatric unit in earlier episodes. Beck felt the role was right for him, as he had attended medical school before training as an actor. He commented, "I love all the medical details and jargon I have to learn. I didn't give up medical school because I couldn't do it, I just got bored with things very quickly at that age. I'm still fascinated by the endless variety of diseases and the questions that arise each time." Beck made his first appearance as Dylan in March 2011.
Development Characterisation and introduction
Shortly after joining the cast, Beck was told by the producers that Dylan should not smile; Dylan often employs sarcasm, especially when he gets frustrated. Speaking to Sarah Ellis of Inside Soap, Beck told her that Dylan finds his work easier to deal with, as he prefers 'known quantities' to people who he deems unreliable. If he can, he will avoid interacting with people and comes across as "shambolic" to put them off. Dylan also prefers to work on the more unusual cases and medical mysteries. Beck thought Dylan unintentionally put people's backs up and this was something that real-life doctors did too. He also said, "Dylan doesn't explain himself very well – his bedside manner is about half a mile from the bedside!" The BBC also described him as "abrupt and tactless".
The character has also been deemed "rude" and "uncaring", and some viewers have speculated that Dylan has Asperger syndrome. Beck said he had his own feelings about Dylan and was happy for people to make up their own minds about him. Beck knew the character from the moment he read the first scripts for Dylan. He shares some similarities with Dylan and understands where he's coming from. Dylan lives on a houseboat, which he shares with his dog Dervla. Beck joked that they were both very important to Dylan, but filming with them could occasionally be difficult. Dylan likes to spend time with Dervla instead of being with other people.
In the official press release for his arrival, Beck explained that in Dylan's fictional backstory he had ended up working as a general practitioner at a surgery in the countryside, despite being gifted at A&E medicine. Dylan was brought to the Emergency Department (ED) by Miriam Turner (Cheryl Campbell), who mentored him, along with clinical lead Nick Jordan (Michael French). Dylan makes a good diagnosis while he is in the ED, which both "impresses and annoys" Jordan. During Dylan's first full shift, he treated Hannah Fleet (Beth Goddard), a woman he had rescued from a bus crash. Hannah blamed Dylan for the facial injuries she sustained and assumed that he would not remember her. However, Dylan recited her medical history from memory and diagnosed her with an infection.
Beck pointed out that Dylan had a talent for diagnosis and working under pressure, making him an ideal ED doctor. Hannah later murdered Ambulance Technician Polly Emmerson (Sophia Di Martino) and Dylan blamed himself for her death. Dylan displayed his rarely seen emotional side when he treated a baby named Lucy. Dylan was initially hesitant when he is placed in charge of her care, but began to enjoy being around Lucy as he treated her. When Lucy's condition deteriorated, she has to be revived. Dylan then accuses her mother of passing on drugs to Lucy through breast milk.
Friendships Producer Nikki Wilson commented that the relationship between Dylan and Zoe Hanna (Sunetra Sarker) was "very interesting". Speaking to Sarah Ellis of Inside Soap, Wilson said that when Beck and Sarker were told their characters had obvious chemistry, they were both surprised. She explained, "In one way, it's great that they're not playing it that way. But we really enjoy their banter, and there's definitely more to happen between them. Whether they'll get together remains to be seen..." Viewers wanted the characters to form a romantic relationship, but Sarker did not think either one of them would make the first move. Sarker also thought Dylan and Zoe were popular because they were not "cuddly" characters.
When Dylan returned to Holby, Beck thought it would be strange if he and Zoe did not continue their friendship, since she had played a role in bringing him back. Beck said that Dylan sees Zoe's presence as one of the reasons to stay at Holby. Sarker was pleased when Dylan was reintroduced to the show. She thought Dylan was more of a brother or best friend to Zoe, and said they had a professional attraction instead of a romantic one. She also referred to them as "a bit of an odd couple" living together on a houseboat with Dylan's dog.
Dylan also developed a friendship with nurse Lofty Chiltern (Lee Mead). Mead enjoyed acting with Beck, as they got on well. He also liked the contrast between Lofty's awkwardness and sincerity, and Dylan's dry and direct personality. The show's executive producer Oliver Kent was a fan of Lofty and Dylan's friendship, describing it a "completely fabulous bromance". Lofty wanted to please Dylan when he received a promotion and Dylan encouraged him to go outside of his comfort zone. Dylan later suggested that Lofty run the ED for the day, but it ended in tragedy when agency nurse Diane Stuart (Catherine Skinner) died. The incident occurred in a lift, where Lofty, Dylan, and Diane were attempting to resuscitate a patient. Diane was electrocuted when she failed to remove her hand from the patient in time.
In April 2016, new nurse David Hide (Jason Durr) was introduced. Following the end of his first shift, Dylan called David "an odd fish", which made Elaine Reilly of What's on TV wonder if they would form a friendship. Durr thought it was something that could happen, as David and Dylan were similar.
Marriage to Sam Nicholls
Towards the end of 2011, Sam Nicholls (played by Charlotte Salt) was introduced to the ED. It soon emerged that she and Dylan were married but estranged from one another. Beck told Lisa Williams of the Irish Independent that it was highly unlikely Sam and Dylan's marriage would work out, explaining, "if I say that we were married in Vegas, that gives you some idea of the longevity of the relationship". Beck also joked that Dylan had a stronger relationship with his dog Dervla than with Sam. Salt hoped that viewers were surprised to learn that Sam and Dylan were married. She thought that both characters were complicated and that they had a troubled relationship.
Sam saved Dylan from being attacked by patient Keith Parr (Marshall Lancaster) by placing Keith in a headlock. Salt said that when Sam saw Dylan's life was under treat, her immediate instinct was to protect him. When Keith later accused Sam of assault, Zoe asked her to meet with Keith and apologise. When she refused, Zoe asked Dylan to try and make Sam see sense. Dylan was "reluctant" to get involved in the matter, but was worried that Sam would suffer for defending him. Sam is later brought before the General Medical Council for her use of excessive force on Keith, and Dylan is called to the stand. He defends Sam, but is shocked to learn from her former army colleague Iain Dean (Michael Stevenson) that he and Sam had an affair. Salt told Sarah Ellis of Inside Soap, "Dylan is very hurt that she never told him what happened while they were together. He finds it hard to hide his real feelings for her when he's being questioned They lose all sense of professionalism, and end up bickering in the middle of the hearing room!"
Dylan and Sam are brought together when they are called out to treat two patients trapped in a cave. The couple tried to stay professional, but when they began to snipe about their failed marriage, they placed themselves and their patients in danger. Salt explained that when Sam receives the call to rescue a pair of trapped dog walkers, she needs someone else's help and the only doctor who could abseil was Dylan. As they climbed into the hole to treat Amanda Franks (Connie Fisher) and David Hooper (Daymon Britton), all of Dylan and Sam's issues about their marriage came to a head. However, when David's condition deteriorated, Dylan and Sam set their problems aside to help save him. Salt commented, "by the end of it, she and Dylan do bond. They realise that, in the grand scheme of things, their argument isn't that important." Sam filed for divorce in secret and planned to tell Dylan in person, before he read the solicitor's letter. When she asks to talk to him after work, Dylan jumps to the conclusion that she wants to get back together and he books a table at a restaurant for them.