"Isolated Incident" is the 858th episode of Casualty and the 35th episode of the 27th series. It featured the final appearance of staff nurse Linda Andrews, portrayed by Christine Tremarco, who joined the department in 2011 during series 25.
A teenage girl is brought in after ingesting an unknown toxic substance, and as the medics question her relatives to find some answers, it becomes clear the family has many unresolved issues. However, Tom isn't coping well after the complaint made against him and when the patient becomes severely oxygen-deprived, he suffers a panic attack. Linda takes sides when she suspects a patient of being harassed by a gang of youths, despite being mocked by Ash for getting emotionally involved, while Fletch and Tess try to sort out their relationship.