Rash returns to the ED and is immediately thrown into dealing with an attack at a market in Holby, while Ethan attends the scene. And David's son Ollie arrives at the ED out of the blue.
Ethan struggles to cope in the aftermath of the incident at the market, and decides to throw himself into his work. When Theo, an old friend from university, arrives at the emergency department with his daughter Effie, who has Cystic Fibrosis, Ethan puts himself on the line to give her a chance. After the loss of his mother, Rash decided to delay his return to work, but soon finds himself helping a mother and baby in desperate need of care. Meanwhile, Duffy worries about the future.
Duffy volunteers at a care home and finds out how overlooked some residents can feel, and she decides to express her concerns to Charlie. Meanwhile, David is devastated when his ex-wife Rosalene calls him because their son, Ollie has run away. David finally finds him on a bridge, but Ollie slips off and is rushed into the emergency department where he undergoes a dangerous procedure. Elsewhere, Ethan pulls some strings to try and get Effie on the CF trial, and Archie returns for his first day back at work.
Archie takes matters into her own hands to try and get justice for a wronged patient, and decides to help him escape from the emergency department before the police can catch him. Already making progress with his mental health after his suicide attempt, Iain runs into an old friend, Dixie, and their chance meeting encourages Iain to think about his potential and his future. Meanwhile, Rash struggles to cope under an increasing amount of pressure, and David finds it difficult living with his teenage son.
Rash's career is threatened when he is blamed for Mason's mistake. Iain's confidence is knocked by Jan and Ruby's surprised reaction when they hear he'll be going for the HEMS job. Effie gets onto the CF trial thanks to Ethan's lies.
David and Ollie continue to butt heads, Rash decides to fight to stay in Holby, and a new member joins the paramedic team.
Mason struggles to ask for help in his most difficult week as a junior doctor, David's bubble is burst when Rosalene starts to fight for custody, and Ethan struggles to convince Effie to go through with the trial.
Despite receiving some devastating test results, Duffy continues to offer her support to others, which results in David and Dylan offering her a voluntary position in the emergency department. Meanwhile, Ethan struggles to keep his personal life from distracting him at work, and Archie turns to Will for help.
Hospital drama with the staff of Holby's accident and emergency department as they deal with more sick and injured patients. Archie is shocked when Vincent, the retired school master who was acid attacked by one of his abused ex-students, returns to the emergency department. Elsewhere, Rashid and Mason finally put their differences aside and make peace when they discover that Leena has Menieres disease, and Ethan finds himself under pressure to rig the trial.
Tension rises between Ethan and Rash when Ethan catches Rash making a personal call, but a potential argument between the two is interrupted when a patient starts coughing up blood and goes in to cardiac arrest. Meanwhile, Rosa opens up to David about her past, and Charlie's frustration grows over the lack of support for Duffy.
Jade is faced with a dilemma after a chance encounter leaves her feeling heartbroken. Meanwhile, Ethan regrets his decisions when Effie is rushed into hospital and he has to open up to Theo about the lies he told so she would not be refused the drug trial. Elsewhere, Danny's impromptu visit to his childhood home does not go to plan.
During a routine CQC investigation, Robyn is devastated to realise she can't rely on Duffy. Ethan stifles his feelings and turns his back on Effie, and Rash protects Mason from Dylan.
Ruby tells Jan that she no longer wants to work with Lev after she learns about his shady past. Rosa and David put their fake relationship into action, and the terror attack continues to haunt Ethan.
It's an emotional rollercoaster of a day for Rash as events take their toll on staff and patients alike. Dylan struggles in his role as clinical lead, and Archie is desperate to impress Dylan but instead accepts friendship from Will.
Jacob attempts to make a difference in two patients' lives, while Ruby helps Archie get to the bottom of an ED mystery.