Casualty kicks off a new era with a major shake-up in the emergency department, introducing Flynn Byron as the new clinical lead. Played by Olly Rix, known for Call the Midwife, Flynn arrives with a mysterious past that includes a secret affair with a woman named Amber during his time as a special forces medic. After a dangerous road accident involving Amber, Flynn is rushed to the ED, where the team fights to save him. The episode unfolds from his point of view, offering a fresh approach to storytelling.

Following a two-month time jump, Flynn returns to the ED, fully recovered, and drops a bombshell on his old friend and colleague, Stevie, revealing that he’s now in charge and intends to make significant changes to the department. This could spell trouble for Tariq, who Flynn had observed making some major mistakes during a previous shift. Although Tariq is excited about the upcoming changes, will Flynn hold a grudge for his earlier errors?

Another revelation comes when it’s discovered that Flynn’s father-in-law, Russell (played by Cold Feet’s Robert Bathurst), is a surgeon at the hospital. Russell initially feared that Flynn’s wife, Claire, had been killed in the accident but later uncovers Flynn’s affair with Amber. Russell’s knowledge of the betrayal sets up a tense dynamic, especially now that they will be working closely together.

Meanwhile, Stevie faces a personal crisis when she discovers that she’s pregnant after falling ill at work. Despite this life-changing news, Stevie keeps the pregnancy a secret for two months. Eventually, she confides in Faith, revealing that the father is her late lover, Rich, Siobhan’s husband. This revelation opens up a new emotional arc for Stevie, who is still mourning Rich’s death and has expressed that she doesn’t want a child. However, as the weeks unfold, Stevie’s situation grows more complex.

In a surprising twist, Dylan discovers that Ngozi has secretly been attending Alcoholics Anonymous meetings for NHS staff, indicating that she’s battling her own issues with alcohol. This adds another layer to Ngozi’s character, who has been a fan-favorite since joining the show. Dylan, a character with a deep and ongoing storyline about his own struggles with alcoholism, could potentially help Ngozi through her difficult journey, creating a powerful storyline for both characters.

Additionally, tensions rise in the ED as a rivalry develops between Rida and Nicole, both of whom work under Russell. Iain and Faith’s wedding is also on the horizon, while student paramedic Indie faces more challenges in her career. To top it all off, the ED is rocked by a dramatic ambulance crash, leaving the team in jeopardy.

This new boxset, Internal Affairs, offers exciting, high-stakes drama, delving deeper into both new and familiar characters. The show’s approach to giving each character their time to shine is working brilliantly, with standout performances from both veteran and new cast members. The upcoming episodes promise plenty of twists and turns, ensuring that fans will be on the edge of their seats for the next 12 weeks.