This episode marks the final appearance and death of Raffaello "Raf" Di Lucca, portrayed by Joe McFadden, after nearly four years on the show. This episode also saw the final appearance and death of Fredrik Johanssen, portrayed by Billy Postlethwaite, who first appeared in the February 2017 episode "Losing Game". The events of this episode take place directly after the previous, which took place in-universe on 5 December.
With AAU left in total darkness, Raf decides to move Rosie to ITU with her newborns and leaves Donna to take care of Ezra. At reception, Fletch assures the staff and visitors that the power cut is likely the result of a blown fuse, and the backup generator will be running shortly; paramedic Iain Dean jokingly suggests that the "Russians have hacked [them]". However, the sound of an explosion resonates through the hospital. In the wet lab, Essie receives a call about a power cut on AAU; at the bottom of the nearby staircase, Jac, who has been shot, groans and collapses.
On AAU, Donna calls Ric about the threatening texts Jeremy Warren has been sending her, but the entire ward frantically runs for cover as a loud gunshot is heard. While protecting Ezra, Donna calls the police. In the wet lab, Essie answers a call about a gunman on AAU, and Hanssen instructs the caller to instigate the major incident procedure and lock down the hospital. Sacha soon finds an unconscious Jac with a bullet wound in her back, and Gaskell tells Essie to fetch the breathing apparatus from a teaching aid. After planning her on a trolley, they rush Jac into the lab.
At reception, Iain emerges from AAU with Rosie and loads her into the back of a nearby ambulance, and Fletch instructs his staff to get as many people out of the hospital as possible before the doors are locked. In the wet lab, as Gaskell sedates Jac with chloroform, Sacha hesitantly proceeds to perform a thoracotomy on her. On Keller, as Lofty confronts Dominic about his snide remarks and belittling demeanour towards him, but Dominic receives a notice on his pager about the hospital being on lockdown and tells Lofty to lock the door. On Darwin, after Ollie removes a large clot from the bifurcation of David's pulmonary artery, all of the medics' pagers begin to bleep, and Morven shows him that the hospital is on lockdown.
In the wet lab, Hanssen believes that the bullet in Jac's back has pierced a major vessel, so Essie leaves to retrieve Jac's handbag. Gaskell suggests fixing the vessel using a printed patch; Sacha vehemently disagrees with experimenting at such a grave time, but Hanssen insists on trying. Sacha reluctantly agrees, and Gaskell proceeds to print a patch. On AAU, Donna rushes Ezra to a ward bay and urges him to stand still behind the curtain. The gunman soon arrives on the ward. Meanwhile, Essie returns to the lab with Jac's handbag, and the medics begin packing her wound with tampons. On AAU, Donna realises that Mrs Henry, a nearby patient, has run out of fluids, so she quickly retrieves her ringing mobile phone. She tells Ric, who is outside the hospital, that she believes Jeremy is the gunman, but Ric urges her not to jump to conclusions and attempts to enter the building. Donna informs Ric that Mrs Henry is lacking fluids and possibly having a post-op haemorrhage.
Outside the hospital, Fletch instructs the other staff and visitors to stay away from the building, but Rosie wakes up and, having lost Ezra and her babies, becomes hysterical. Iain informs Fletch that she will not let him treat her or take her to St. James Hospital. On Darwin, Ollie decides to close David's pulmonary artery and take him off bypass, but Morven is preoccupied with watching out for the shooter. Ollie and Roxanna remind her that their duty of care is to David, and they cannot leave him irrespective of the situation. On Keller, a shaken Dominic urges the other staff and patients to remain calm and not share any information that is not based in fact. Privately, he tells Lofty that the ward's occupants are "exposed" and suggests moving all mobile patients to the far end of the ward. Dominic puts the plan into motion and assures everyone that the police are dealing with the situation.
On the ground floor, armed police begin to storm the hospital and lock the entrance doors. Fletch insists on being allowed inside to coordinate the major response for the hospital's staff, but Sergeant Taylor urges him to allow the police to do their jobs. On AAU, Ric collects several bags of fluids, but he is stopped by the police. Ric insists that Jeremy is the shooter, but Donna appears and tells him that she saw the gunman. In the wet lab, Gaskell explains that the patch he has created has not been tested on humans, and Sacha dismisses his plan as "science fiction". As Gaskell answers a call, Hanssen attempts to have equipment sent down to the basement. Once Hanssen finishes his call, Gaskell informs him that the shooter has been identified. On Keller, Dominic is left shocked when Lofty shows him a photograph of the gunman.
Outside, Sergeant Taylor is handed a photograph of the gunman and told that he may be using a pass. After Fletch views the picture, and Taylor learns that the shooter is ignoring civilians and targetting hospital staff, Taylor asks Fletch if he can think of any specific targets. On Darwin, Ollie closes David's pulmonary artery and takes him off bypass, but a loud bang is heard on the ward; Roxanna insists on continuing. Back outside, Fletch informs Iain that the police are setting up a safe area inside the hospital, and the gunman has been identified. In the wet lab, while Gaskell finishes printing the matrix, Essie puzzles over the shooter's motives, suggesting that, if Jac is a target, anyone is. Meanwhile, after searching Hanssen's office, an armed unit tackles a man to the ground.
On Keller, Lofty urges Dominic to stay calm and asserts that he is not a target, but Dominic contends that Lofty is "not the one he had a problem with". Lofty tells Dominic that he is scaring people, but Dominic claims that he is putting people at risk and asks Lofty to help him move everyone else into theatre. Elsewhere, the armed unit informs Taylor that they have found the wrong man, and the subject is still on the move. At reception, Donna tells Ric that she cannot find Ezra's mother, but Ric assures her that what she is doing is "nothing short of heroic"; she decides to call Mia.
On Darwin, Roxanna instructs Morven to remain focused on treating David, but the gunman soon appears and enters the theatre. Roxanna and Ollie urge him to put the gun down, but a shot is fired. Hanssen arrives on the ward and discovers that Ollie has been shot in the head. Roxanna orders Hanssen to go and stop the shooter before he injures others. On the ground floor, Fletch is allowed inside the hospital and tries to get to Darwin, but Ric urges him to have faith. Donna encourages Ric to leave the hospital grounds before he is caught, but she quickly returns to Ezra after he is reunited with Rosie.
In theatre, clueless as to why David's pressure is so low, Roxanna decides to aspirate his carotid artery, but Ollie begins to have a seizure. Morven tells Roxanna that David is having a cerebral haemorrhage, whereas Ollie desperately needs a neurosurgeon; Roxanna eventually decides to prioritise Ollie. In the wet lab, Gaskell prepares to insert the patch, but Sacha refuses to move, insisting that it is "a risk too far", and proposing waiting for Hanssen to return with equipment. However, Gaskell is adamant that Hanssen is not coming back. In the theatre on Keller, the gunman attempts to force the doors open but is unable to budge Dominic and a wall of shelves. The shooter - Fredrik Johanssen - prepares to break the window using his gun, but Hanssen shouts his name, prompting a confrontation on the ward.
In the wet lab, Gaskell inserts the matrix, but Jac's pulse continues to fade. However, once the patch holds, her pulse returns. On Keller, Taylor and his team arrive, and Hanssen attempts to negotiate with Fredrik, but Fredrik claims that he does not want anything from his father anymore. Hanssen urges him to put the gun down, warning him that the police will be forced to shoot him, but Fredrik loudly declares that he will decide how the situation will end. On Darwin, Roxanna discovers that Ollie's frontal lobe has been macerated, and the bullet has completely fragmented inside his skull; only a few metres away, David's heart starts fibrillating, forcing Morven to shock him. Unsuccessful, Morven is forced to perform cardiac massage.
In the wet lab, Essie informs Sacha and Gaskell of Fredrik's whereabouts and Ollie's injuries, and Sacha promises Essie that Raf will be safe. However, they hear a bang, and Gaskell is confronted by arm police. He explains Jac's situation to them and instructs Essie to collect all the necessary equipment. On Keller, Fredrik overhears a news report on the television branding him as a "once disgraced surgeon" and remarks that "mud sticks". Suddenly, Dominic tries to apologise to Fredrik, but Hanssen orders him to leave. Fredrik asserts Hanssen is not a part of the family that is the hospital, and neither of them "cope". Hanssen claims that Fredrik is not himself, but Fredrik disagrees and announces that he is "here to end it". As the two size each other up, the police shoot Fredrik. Desperate to save his son, Hanssen demands for theatre to be prepared, but Taylor warns him that the bullet has gone into Fredrik's chest, and Hanssen should "prepare for the worst". Regardless, Hanssen instructs Dominic and Lofty to activate the major haemorrhage protocol, and the police help lift Fredrik onto a trolley.
On Darwin, Morven fails to resuscitate David and proposes performing a decompressive craniectomy to release the pressure, but a distraught Roxanna tries to tell her that there is no output. At reception, Ric finally decides to leave. Essie recognises Rosie and tells Fletch that Raf was supposed to be with her, and Fletch tells her that Rosie's wounds were caused by shrapnel. On Keller, Hanssen rushes Fredrik into theatre and orders for the lift to be put back on, but he soon begins to realise that Fredrik is gone. Meanwhile, Roxanna pronounces David dead and tells him that he is "at peace now". On Keller, Dominic and Lofty leave Hanssen alone to grieve.
As Ric leaves the hospital grounds, Sacha informs Gaskell that the lifts are back on, and David and Fredrik are dead. On Keller, Essie rushes into the staff room to retrieve her phone and listens to a voicemail from Raf. However, he tells her that he has been shot in the jugular, and he is not scared of death because she helped him be the "real" him by being the "real" her. On AAU, Fletch calls for Raf and desperately tries to open the lift. In the basement, Sacha and Gaskell are devastated to find Raf's body in the lift. In the voicemail, Raf urges Essie to be strong for their friends and claims to not be alone as he can see her face, but she begins to break down and drops her phone. On Keller, while Dominic and Lofty comfort each other, Hanssen finds his token and laments on Fredrik's actions. Meanwhile, on ITU, Gaskell consoles a heartbroken Roxanna. On Keller, Sacha and Fletch run to Essie's side and embrace her.
On ITU, Gaskell asks the staff to respect Hanssen's decision to remain silent on the day's events, and many people have volunteered to cover for them if they wish to go home. He suggests that someone "that represents [the hospital]" should speak to the press, and Sacha agrees. Later, Gaskell hands Sacha a script, and Sacha approaches the reporters. After being bombarded with questions, Sacha explains that what happened was not something "anyone thought possible", and he has never been prouder of "a group of ordinary people who, in extreme circumstances, proved themselves to be extraordinary". Regardless, the reporters start shouting over each other again, and Sacha quietly turns away.
- Jaye Jacobs as Donna Jackson
- Joe McFadden as Raffaello Di Lucca
- Alex Walkinshaw as Adrian "Fletch" Fletcher
- Kaye Wragg as Essie Harrison
- Paul McGann as John Gaskell
- Guy Henry as Henrik Hanssen
- Bob Barrett as Sacha Levy
- Rosie Marcel as Jac Naylor
- David Ames as Dominic Copeland
- Lee Mead as Ben "Lofty" Chiltern
- Hermione Gulliford as Roxanna MacMillan
- James Anderson as Oliver Valentine
- Eleanor Fanyinka as Morven Digby
- Hugh Quarshie as Ric Griffin
- Billy Postlethwaite as Fredrik Johanssen
- Joe Citro as Ezra Cranham
- Michael Stevenson as Iain Dean
- Fraser James as David Hopkins
- Komal Amin as HL1 TV reporter
- Victor Gardener as Sergeant Taylor