In the 40th-anniversary episodes of the long-running British medical drama Casualty, a significant event unfolded involving the character Sophia Peters, played by actress Kellie Shirley. Sophia, a psychiatric liaison nurse, was introduced in 2024 and had formed a relationship with Dylan Keogh, portrayed by William Beck. She left her role at Holby ED in February 2025 to take a new position at St James’ Hospital. For the anniversary specials, Sophia made a surprise return, and her storyline had a profound impact on Dylan, who was left emotionally devastated by her fate. Sophia suffered severe injuries during an explosion at St James’ Hospital, which caused widespread chaos. Dylan, now leading his team through the emergency, was tasked with managing the crisis. As he prepared to move outside, he opened another ambulance door, allowing Matty Linlaker (Aron Julius), Dylan’s son, to enter and assist with treating the next wave of patients. Matty began assessing a woman with extremely severe burns from the blast. When Dylan looked over, he immediately recognized the woman as Sophia. Despite his desperate efforts to save her, Sophia’s injuries proved too severe, and she died within the hospital. Dylan was left in a state of deep emotional turmoil after her death. Kellie Shirley, who portrayed Sophia, spoke to Metro about her experience in the anniversary episodes. She expressed excitement about being asked to reprise her role and described the process of being covered in burn makeup as surreal. She praised the makeup team for their incredible work and noted that Sophia’s relationship with Dylan was a key element of her character. Kellie also mentioned that it was meaningful to "go out with a bang" for Sophia, highlighting the emotional weight of the character’s final moments. The episode marked a dramatic and emotional milestone in Casualty’s 40th anniversary, showcasing the show's ability to tackle intense and realistic scenarios. Sophia’s storyline not only added depth to the characters of Dylan and Matty but also underscored the show's focus on the human impact of medical emergencies. Her death served as a powerful reminder of the unpredictable nature of the work undertaken by hospital staff.