Sebastian "Seb" Grayling is an F1 junior doctor who worked in the emergency department of Holby City Hospital from October 2016 to January 2017. Coerced by his father into a career in medicine, Seb joined the department nervous and eager to please his colleagues but was only put-off by his father's frequent visits. On New Year's Day in 2017, Seb left the department shortly after withdrawing an allegation against Dylan. Dylan also secured him another placement at St. James Hospital, so he could have the opportunity for a fresh start.
Seb arrived for his first shift at the ED at the end of October 2016, as a result of his alarm clock being one hour behind. On his way there on his bike, he hit Dylan's dog Dervla which resulted in her going missing. Elle had already had a surprise that morning when Dylan had offered to mentor the new F1. Seb failed to impress the staff with his witty comments, and this only seemed to irritate them. As well as jumping to a conclusion on a patient's diagnosis, he went missing whilst trying to look for Dervla outside. Shortly after, Seb discussed the patient's results with her daughter which breached her patient confidentiality. When Dylan left and the patient went into cardiac arrest, Seb resuscitated her although she had a DNR. Dylan was furious when Seb said that he was simply following the daughter's wishes. A meeting with Elle went badly when she informed him that she'd have to suspend his rotation. As he was leaving the ED, he found Dervla and brought her into the staff room to treat her. In resus, Dylan found Seb and told him that he'd give him a second chance as long as he followed the rules.
The following week, Dylan and Seb clashed with Seb's father Archie over the treatment of a teenage patient. During the shift, Dylan noticed that Seb's actions around his father were distracting him from his work, and hindered his decisions made during the shift. As a result of the clash, Archie told Seb that he was able to pull some strings so Elle could be his mentor. However, at the end of the day Seb refused to accept the change and pledged to stand by Dylan.
Later in November, Seb suspected that one of the patients he was treating had meningitis when David spotted a rash. However, Dylan was angry when he discovered that they hadn't informed him about it straight away. Although the patient was okay, Dylan was still angry about their failure to keep him informed. Towards the end of the shift, Dylan brought up the incident in reception in Cal's defence after the nursing team were annoyed with him. At this point, Seb's father Archie revealed himself as the ED's undercover inspector, shocking everyone including Seb.
In December, Seb failed to save a patient during a shift and blamed himself, although Dylan assured him that there was nothing that he could have done. To make Seb feel better, Dylan agreed to go to the Christmas party after work. However, when Dylan didn't show up, Seb went to his houseboat. Seeing Seb miserable and drunk, Dylan attempted to comfort him. Despite this, Seb mistook Dylan's empathy for flirting and went in to kiss him. When Dylan backed away, Seb ran out of the houseboat, mortified.
The following day, it was Christmas Eve and Seb was eager to make sure things weren't awkward between him and Dylan. He even got him a present as a peace offering, but Dylan simply carried on as normal as though nothing had happened. Towards the end of the day, Dylan got angry with Seb over the treatment of a young boy when he'd failed to thoroughly check for symptoms. He warned Seb that if he didn't get his act together in the new year, he'd be forced to fail him. In desperation, Seb told Elle that Dylan had tried to kiss him the night before to try to get Dylan into trouble.
By New Year's Eve, Dylan appeared to have given Seb a new opportunity to show his skills which made Seb think about retracting his allegation. Although Elle agreed not to go to HR, she told him that changing mentors would require him to redo the whole rotation. Whilst treating a patient, Louise soon picked up that something was amiss and he told her that Dylan had tried to kiss him. Later, he told her that he'd told Elle but she didn't believe him, but Louise was quick to tell Seb about the photo which had Seb and Dylan hugging in the staff room in the background. Meanwhile Dylan had told Elle that the story was fabricated when Max hinted to him that something was wrong, but Louise had already spread the gossip. After stabilising a patient, Dylan told Seb to think carefully before he made it official, as it'd be his own career he was ruining. Things came to a climax towards the end of the day in front of the staff, when Dylan confronted Seb about his lies. However, due to a lack of evidence on Dylan's side, Elle told Dylan to go home, and assured Seb that she'd be contacting HR.
The following day, Jez and Max tried to catch out Seb confessing to lying, but it all went horribly wrong when Seb caught them in the act. Although Elle had told Dylan he was not to be on clinical duties, he remained at work anyway, much to Seb's annoyance. However, when Seb froze in resus, Dylan stepped in and encouraged him once again. This made Seb reconsider the allegations, and he went to see Ric Griffin and Elle to make his confession. Dylan was relieved that it was all over, but out of kindness he secured a rotation for Seb at St. James Hospital, as he believed that he was still a good doctor.
- Seb's father, Archie Grayling, is a top surgeon.
- Dylan was Seb's mentor.
- Seb started working at St. James' Hospital following his departure from Holby in January 2017.
Behind the scenes
Rik Makarem portrayed Sebastian on Casualty, and likely began filming in summer 2016. He was first seen in the Autumn 2016 trailer which was released on 31 August 2016. Prior to this, neither the character nor Makarem's casting was known.
Although it was revealed that his first appearance would be in November, Makarem made his first on-screen appearance on 29 October. This error was a result of the merging of episode 1 and 2 of the series which essentially brought all airdates forward one week as well as the episode numbers in the series being shifted down one. Makarem made his final appearance as the character on 7 January 2017.