As Jeff and Dixie clean out their ambulance new team members Omar and Tamzin show up. Tamzin makes a bad first impression after she accidentally breaks Jeff's A-Team mug. Jeff and Dixie end up called out to a remote farmhouse, where a drugs baron and a pack of ferocious dogs live. Jordan is concerned that the symptoms of his brain tumour are coming back.
Scarlett and Lloyd start their first shift in the ED as a pair of new nurses. Teaching assistant, Harry finds himself coming unstuck in his new job.
New mother Annie, skateboarder Richie, white-collar worker Chris and teenager Fiona are admitted with sickness and dilated pupils. The race is soon on to get to the bottom of the mystery as their conditions get worse. New nurses Lloyd and Scarlet find it hard to cope with the emotional demands of their positions.
Rachel comes into the department with a fractured leg which happened as she tried to run away from a stalker. Rachel's pursuer looks to have followed her to the hospital, and security is stepped up. When her husband shows up he tells the team that her stalker is just in her mind. Zoe is surprised to find out that Dylan is a Basics volunteer, who assists paramedics at the scene of accidents. Lloyd ends up clashing with Jay.
Jesse falls from a rope ladder and keeps passing out. Ruth and Jay treat him but as his condition gets worse he needs surgery straight away to relieve the pressure in his brain. Lloyd is responsible for keeping an eye on the injured Seb, who wants to get home to his wife. Lloyd races after he slips away and ends up making a shocking discovery at his house. Ruth ends up being grateful for Jay's support.
Annie and Chloe return to the hospital as Chloe is being treated for a blood clot on the leg and Annie believes that she's using again. When dealer Felix shows up, it puts Chloe's safety and the future of the clinic under threat. The appearance of an estranged brother at a funeral ends in violence and a long-held family secret ends up being revealed.
Chloe is in a really bad way following her beating from a drug dealer, and her friend Annie stays by her bedside. Jordan is blamed by Linda for closing the drugs programme which would have kept Chloe and Annie safe. Dixie pairs up Omar and Jeff for the day, fed up with their arguing.
Charlie finds himself stuck in a traffic jam and a teenager blacks out on a road bridge and ends up falling onto his car. The girl called Maya believes that she sees angels and that Charlie is their instrument on Earth. Her condition ends up perplexing all of the ED team. Zoe ends up taking control of the case and is forced to act quickly to save Maya's life after she blacks out again. Scarlett doubts her abilities to be a good nurse and she finds her resolve being tested during a difficult shift at work.
Charlotte Salt (The Tudors) joins the cast as Sam Nicholls, an ambitious Army medic on secondment. She begins by joining a paramedic crew for the day, but has to rely on her military training when an aggressive driver rams the ambulance off the road. Meanwhile, Noel is keen to increase security after a run-in with an angry patient, but an encounter with a grieving mother (Tracie Bennett) changes his mind
Desperate for a fix, Annie makes contact with Linda, who steals some Valium to help her deal with her withdrawal symptoms. Linda is attacked by Annie's unhappy pimp, Damon as she leaves her house. After Damon confronts Annie she hits him with a wine bottle and they both end up in the hospital. Damon and Annie are later discharged, Linda is shocked to find out that they've returned to Annie's house together and she risks Tess's anger to go and help her. Dylan is surprised to meet new recruit Sam and it soon becomes clear there is some history between them.
After 16-year-old Jamal is released from prison after serving a sentence for a fatal stabbing, his victim's sister Ketzia decides to get even with him and ends up inadvertently hurting Jamal's young brother. The violence increases when Jamal's family retaliates and Ketzia's mother, hospital volunteer Rosa, is attacked. Jeff and Dixie think that elderly patient Malc is using their ambulance as a taxi service until Lloyd manages to get to the bottom of the mystery.
Dixie is not pleased after she is forced to take a call during her break, especially when it looks like it's a hoax. She ends up telling Louise that it's not safe for them to work without any breaks. Esther comes into the hospital and her 'mother', Saskia, takes an instant dislike to Dylan, who soon works out that Saskia is not all she seems. Some youngsters are planning a revenge attack on a drug dealer but their scheme does not go to plan. Louise ends up taking the emergency call for a shooting but Dixie refuses to go as she's on a break. As the victims are brought into the hospital, Dixie is shocked to learn that her decision could have cost a life.
Caitlin and David are traveling to the coast for a romantic weekend full of memories. After David's serious illness gets much worse, they find themselves at the hospital. Ruth and Jay attempt to help Caitlin let go and make the most of the time they have left together. Dylan and Sam manage to put their differences aside to diagnose a mystery condition.
Ruth's medical condition gives her reason to think again about her mental health medication. Jay believes that she should come off the lithium but Ruth is scared that she could suffer a mental health relapse. After Jordan suggests that she come off the lithium, Ruth is not happy with Jay for interfering. Dixie is fed up following the events which led to the shooting and Jeff offers her some advice.
Ruth and Jay's relationship is going better than ever but after a patient says he is damaged, it ends up striking a chord with Ruth and some old insecurities begin to resurface. After talking to the patient's mother, Ruth ends things with Jay. Linda's former adversary Damon is back working at the hospital. He works out that she lied to him about Evie's parentage and makes plans to kidnap his baby. Frank discovers some potential fire hazards in the department which ends up leading to trouble.
With the fire alarm being declared faulty and both the staff and patients tback into the ED, Lenny and fire officer Frank manage to escape a fire in the basement and alert everyone else. Jordan attempts to arrange an evacuation and Dylan and Zoe end up rushing the hurt Frank into resus for help. Ruth is confronted by Jay demanding to know why she's dumped him. As they argue they have no clue about the fire raging around them. Zoe and Dylan end up becoming trapped in resus following an explosion.
Feature-length episode in which the refurbished ED opens for the first time since the fire. The new facilities are put to the test when a traffic accident occurs on a nearby dual carriageway, and a pipe explosion causes a cloud of poisonous gas to engulf Holby. The staff are stretched to their limits despite the efforts of new paediatric doctor Tom Kent (Oliver Coleman), and as tempers fray, a patient lashes out at Dylan. Guest starring Marshall Lancaster (Ashes to Ashes) and Colin Buchanan (Dalziel & Pascoe).
Following his heroics during the Silverton Explosion the previous day, Tom formally joins the team at the ED and his first case soon turns into a mystery when a family caught up in the explosion return to the ED with mysterious injuries, but when a young son from the family is then kidnapped, Big Mac turns into an unlikely hero. Dylan accuses Sam of meddling with a patient's home life, and Jordan's feathers are ruffled by an attractive young DCI.
When Lloyd insists on helping a patient he ends up inadvertently putting her in greater danger. Linda finds her life being turned upside down when her drug addict sister and children show up at the hospital.
Linda is faced with a problem when Denise fails to return for Britney and Joe, and Dylan meets his match when he treats an acerbic homeless man involved in a traffic accident.
Hospital drama. A woman learns she cannot cope with the challenges of looking after her beloved mother, who has Alzheimer's.
Sam throws herself into treating a patient she believes has been sexually assaulted as a way of distancing herself from her own problems with Keith Parr, much to the worry of Zoe and Dylan.
Paramedic Rossy starts working at the hospital and he enjoys works alone and he's getting to all the shouts quicker than Jeff and Dixie. Jeff likes the fact that Rossy's willing to go into potentially dangerous situations to get the job done but Dixie thinks he could be too good to be true. Tara is preparing for a special meal with her boyfriend but her younger sister Gemma is less than thrilled about the idea of them getting married. Her erratic behaviour ends up seeing her falling off a roadbridge while in a dazed state.
Britney goes to the hospital after head-butting a girl at her foster home. After Linda tries to reason with her, the girl runs off. After falling in with a crowd a bad teenagers, they attempt to teach Linda a lesson by texting her to say that they've kidnapped Britney Linda ends up realising that wants to care for her niece and nephew after all. Sam is is ordered by Jordan keep her head down after a complaint is made to the GMC. Sam is soon back to her old ways though after an encounter with a pompous parent and consultant Hugh Blakeney.
Stevie finds himself being drawn into the Farmead Crew by his half-brother Kris, despite the positive influence of his grandmother in his life. In an effort to prove his loyalty to the gang, Stevie is persuaded by leader Anton to shoot at a rival drug dealer to keep him away from their patch. Things don't go to plan and a small boy is caught in the crossfire. Stevie is brutally punished by the gang for messing up and the gang members show up at the hospital attracting the attention of Superintendent Yvonne Rippon.
Following the shooting which has injured a young boy, Stevie's girlfriend Jade is shocked to learn that the gun used has been hidden in her wardrobe by Stevie. Stevie learns that Anton is becoming paranoid about him confessing to the police. Jade ends up being lured to a lock-up garage where she is unhappyly assaulted by the Farmead Crew. Stevie ends up admitting to her that he was the shooter after she is taken to the hospital. Jordan and Tess have to decide whether to break patient confidentiality and tell Yvonne about Jade's attack.
Concerned about the consequences of the bungled shooting and Jade's unhappy assault at the hands of the gang, Stevie and Jade are determined to leave. Lloyd and Scarlett attempt to get them to change their minds but they're adamant, until Jade's condition gets worse and she's taken back into the ED. After Yvonne learns the truth about Jade's assault, she is furious that Jordan and Tess failed to disclose the information.
Following an allegation against Sam by ex patient Keith Parr, a GMC official shows up to talk to Sam's colleagues. Zoe and Scarlett have to answer questions but Dylan goes out of his way to try to avoid being quizzed. In an effort to distract herself, Sam tends to a cantankerous old soldier who softens after he discovers that she was an army medic.
Jordan's upcoming date with Yvonne has to be cancelled after a former ED patient collapses in prison after being arrested for assaulting Lloyd. The pair's relationship is threatened as it becomes apparent that one of them may be held accountable for the man being left in a cell. Linda and Zoe enjoy a girls' night out and run into a teenager who needs help.
As David and Amanda are out walking their dogs the ground gives way and they become trapped in an underground cave system. Sam has to combat her fear of the dark to treat them. Dylan shows up to help as David admits that he has been too scared to ask Amanda out. Dylan and Sam start to argue about cowardice in their marriage. Amanda and David's conditions get worse and Sam and Dylan have try and put aside their differences to save them.
Alicia is back at the hospital after having collapsed at school and Tom is determined to get to the bottom of her symptoms. Linda thinks that Alicia's problems are psychological and that she has developed an unhealthy fixation on Tom. Rosemary decides to take action against her nuisance neighbours by setting her house on fire, but is then shocked to wake up at the ED to find her neighbour's son Connor has rescued her. When Connor is implicated in starting the fire, Rosemary has to decide whether or not to own up to her actions.
Tensions increase as Sam gets nervous about her GMC hearing. Lenny ends up making a pass at Linda. Lloyd and Scarlett's fiery relationship causes problems at work.
It is judgement day for Sam as she has to face a fitness practice hearing at the GMC after restraining Keith Parr, the relative of a patient. Her past could come back to haunt her after former colleague Corporal Dean steps up to give evidence.
Dixie and Jeff bring nine-year-old Luke into the hospital with a suspected head injury. After he passes away, Dixie believes that there are suspicious circumstances and calls the police. Jeff is angry as he knows the boy's father and is convinced that he had nothing to do with his son's death. Dylan believes that Sam wants to get back together with him. Zoe realises that Sam actually wants to serve him with divorce papers though and attempts to convince Sam to finally tell Dylan the truth.
A fed up Dylan is finding it really hard to work alongside Sam, but when they are forced to liaise over a disabled patient and his over-protective daughter, they end up reaching an uneasy truce to get to the bottom of the case, causing Sam makes an impulsive decision after the tension becomes too much for her.
Lloyd becomes very possessive of Scarlett, irritating her and affecting his work. Lenny receives a tempting job offer from London and has to decide where his future lies.
After a school roof collapses, Tom ends up being reunited with a troubled teenage girl, who he has previously recommended for counselling. The girl's jealous boyfriend claims that she doesn't want Tom treating her, so Jordan ends up taking him off the case for his own safety, but Tom ends up refusing to stop treating her. Linda believes that she's making progress with Joe and Britney and that they have begun to behave like a real family. After she organises a shopping and pizza trip, Joe is too ill to go and Britney feels angry and threatened by Linda's increasingly close relationship with her little brother.
Clive comes into the ED with some serious injuries, but he lies to his family about how he got them. The mystery increases after a strange woman claiming to be Clive's wife shows up at his bedside. Charlie works out that Clive has been harassed by some loan sharks. Linda has no choice but to bring a suspended Britney into work with her. After Lenny finds out that Britney has arranged to meet somebody she's been talking to in a chatroom, he chases her out of the ED and she ends up getting into a car with the stranger. Scarlett's first meeting with Lloyd's family doesn't go the way that it was hoped for after she turns down his mum's dinner.
Lenny and Linda begin to look for Britney after she gets into the car with a mysterious man. Dylan diagnoses a mini stroke due to sickle-cell anaemia, for a man rushed in after being involved in a fight.
As Sam gets ready to return to the army, new nurse called Fletch joins the team. After Sam falters during a training exercise she is forced to ask herself whether she will ever be ready to face a war zone again. As she is returning home she meets Captain Morrison, a former army colleague, who has been involved in an accident. Believing that he has had an epileptic fit she is torn over whether she should tell the army the truth about her suspicions, which could end his military career for good. Fletch is making a good impression on everybody except Lloyd.
Having been just released from prison and determined to turn his life around, Wesley is upset to find out that his wife Faith is still dealing drugs. After the police are alerted to a unhappy argument at Wesley's home they come prepared for trouble and end up using a stun gun on Wesley, not realising that Faith has already attacked him. After he suffers some serious complications in the ED, Jordan and the team question the police involvement. Dylan and Sam are still at odds, with Dylan refusing to sign the divorce papers if Sam persists in remaining at the hospital.
Jordan and Yvonne have to give evidence about Wesley Joyce, the man who passed away in the hospital after being Tasered by police. They end up arguing after Yvonne claims Jordan is refusing to support her case. Scarlett goes with Lloyd to a vigil for the dead man but the ceremony descends into violence and she finds herself being caught up in the moment and does something she could live to regret forever.
Jordan is forced to undertake some dangerous surgery on his girlfriend as the riots block the route into the ED. A vigil for Wesley Royce becomes a full-scale riot, and Scarlett is swept along with the rioters. She finds herself being pressured into helping a severely injured rioter.