P.C. Ken Melvin and P.C. Reg Hollis stop a young man for erratic driving, and a PNC check reveals the expensive car is stolen. Stamp and Quinnan arrive to transport the prisoner to Barton Street, and Melvin and Hollis volunteer to drive the car back to Sun Hill. As Melvin moves some of the building materials from the station renovations so he can park, the car explodes in a huge fireball. Hollis, Conway and Melvin are rushed to hospital - but Ken Melvin soon dies from his injuries. SO13 arrive at Barton Street to interview the car thief, who it turns out stole the car from an army major who was a likely terrorist target. Sgt. Cryer is outraged that the disaster could have been prevented as SO13 had the major under surveillance and could have stopped the car being stolen.

Two explosions happen whilst Emma and Sally are out on patrol. With many casualties Callum takes control of the situation. Emma learns from Jack about another possible bomb and as she tries to evacuate a building it goes off.

With a gun to Harman and another on him, Nadir is forced to admit he is undercover. As Haskew, Shaw and Nadir dispute on whether or not Nadir is actually bent, Alvarez silences the room by shooting informant Eva Garcia. As Haskew drags Harman and Nadir to the drug deal, Nadir explains all to Harman, leaving her disgusted. With SOCA at the wrong location, the lorry is intercepted with it continuing in the wrong direction, but it is a bust. Nadir proves to Alvarez that the police are going to the wrong place to regain his trust, but he loses Haskew's when he tries to shoot him in attempt to stop Haskew killing Harman. A heart to heart between Nadir and Shaw sees them decide to elope with the cash, but not before CO19 storm the deal and engage in a firefight. As bullets fly and bodies drop, the Sun Hill team are left looking for their own in the casualties.

It's the day of P.C. Ken Melvin's funeral, but the men and women of Sun Hill still have a job to do. P.C. Stamp volunteers to do a reading at the church service. W.D.C. Martella is annoyed when D.I. Burnside keeps CID out on an obbo when the funeral service is about to start. Two old friends turn up at the church: P.C. Taffy Edwards, now in the Wales Police, and Yorkie Smith, now working for a security firm. The funeral goes off without a hitch, as Sun Hill pays its last respects to one of its officers.

PC Eddie Santini tries to convince his lover, Jess Orton, to set him up with some drug dealers - he wants out of Sun Hill, and DS Timpney, his friend in Area Drugs, has promised him a place in the squad if Santini can get him evidence on them. At parade, Sgt. Bob Cryer assigns the relief a door-knocking campaign to warn the elderly residents of the area about two bogus callers posing as social workers who are responsible for a string of robberies. Leaving PC Hagen to cover for him, Santini meets Jessica, but not before hearing the culprits have been following the local Meals-On-Wheels van. Jessica has met up with an old friend, Ferguson, who is a big-time drugs importer. She wants Eddie to pose as her husband when they next meet to seal the deal. When Eddie returns to duty, Cryer is furious. An old army Major has had all his medals stolen by the bogus callers, and Santini had neglected to warn him. A desperate Santini gets Hagen to investigate the Major, and finds his claim is a scam.

PC Nick Klein is back in the safe house, but when DS Phil Hunter gives the address to Dennis Weaver, a hitman is contracted to kill Klein. Meeting with the hitman to retrieve the gun and a photo of Nick's body, Weaver realises Hunter has set him up when the police lead by Supt Okaro and DCI Meadows swoop in on them. Escaping into North Canley Forest, a terrified Hunter barely escapes with his life as a maniacal Weaver swears revenge for his treachery. With Weaver on the loose, however, Nick Klein is relieved of duty and placed in deep witness protection far outside of London, but not before Hunter and Sgt Dale Smith have a chance to clear up their differences with him. Police Staff Polly Page investigates a forged drivers licence, but is reprimanded for exceeding her remit as a civillian staff member. Polly visits Cathy Bradford in a secure psychiatric unit, where Cathy tells her she is ""undercover"" in the hospital. Considering recent events and Bradford's taunts, Polly resigns from Su

Carver is let down by an unreliable snout, and needs Beech to get him out of a tricky situation.

DS John Boulton is determined to catch a pair of brutal thieves, and he is certain that local crook Mick Glover is one of them. Ignoring protests from Uniform, who already have Glover under surveillance, Boulton leads a disasterous raid on Glover's flat, which puts PCs Quinnan and Garfield's informant Janie in grave danger. When Quinnan and Garfield find Janie's flat on the Jasmine Allen estate vandalised, Quinnan pursues the suspects, but finds himself seperated from Garfield, who can only watch in horror as his friend is beaten and stabbed by a gang of youths.

Ackland uncovers a series of muggings. Johnson is unimpressed, but Monroe, acting on Ackland's information, organises an observation on a pub.

Boyden, Ashton and Santini head out for a night in a club, and Boyden bets his PCs that he can pull any girl in the club. Approaching an attractive young blonde, he ends up taking her home. The following morning, Boyden attends an assault on the girl's stepfather and discovers she is only 15. The case soon escalates when the girl's younger sister claims she has been abused by her stepfather's friend, and when Boyden's conquest runs away, she tracks him down and demands he provide her an alibi for the assault. When Boyden refuses, the girl is arrested for trashing a pub, and uses the interview to mention her night of illegal passion with the Sun Hill lothario. As CIB interview Boyden, Hagen is tasked with taking the girl to a children's home, but she cons her way out of the car and runs off. An off-duty Boyden then goes after the girl, but is unprepared for a discovery during his search.

Meadows recruits Quinnan and Rawton to receive a notorious sex offender, Ray Ballantyne, from another division. However, the DCI's hopes of keeping the Ballantyne's identity a secret are quickly blown by a press leak. As a protest takes place outside the safehouse, Hagen receives a call in CAD that a local boy, Andy Donnelly, has gone missing. TSG are drafted in to take Ballantyne out of the house and back to Sun Hill, as the protest escalates into a low-scale riot. Meanwhile, Page and McCann interview Donelly's friend, he gives a vague description of a man seen with the missing boy that matches Ballantyne. As the protest shifts to Sun Hill, Ballantyne is interviewed about his involvement, and he confesses to seeing Donnelly and comforting him. As the boy is tracked down after hiding in an abandoned train, he makes a shock confession about his home life. Back at the station, as Rawton struggles to find a hostel for Ballantyne, a dramatic twist brings a final resolution to the case.

With PC Quinnan in a critical condition in St Hugh's Hospital, the police descend on the Jasmine Allen estate, determined to catch those responsible. PC Garfield manages to identify most of the gang, and a young boy, Kevin White, bought in for questioning names them as the 'Sun Hill Massive'. Garfield and DS Boulton come to blows when Boulton denies any responsiblity for the attack on Quinnan. Acting on a tip-off, the police raid Mick Glover's flat again, finding he is responsible for the burgleries, and that his son Ben and Kevin White were the ones who stabbed Quinnan.

Vicki Hagen finds Eddie Santini's tickets to Amsterdam, and questions him about them, but he is evasive. DCI Pallister takes DS Fox off the Jessica Orton case after her accusations against Santini, but she decides to do some investigation of her own. Santini, meanwhile, acquires a gun and some Class-A drugs to plant in Ferguson's boss's house when DS Timpney and the Area Drugs Squad raid it. Fox stumbles upon the house and is captured by Ferguson. His boss Mr Sherman is displeased that Santini allowed a police officer to find them. When Area Drugs arrive at Sun Hill for the raid, CID realise that both Santini and Fox are in trouble. Sure enough, Ferguson's radio scanner warns him of the forthcoming raid and he locks Santini in the same room as Fox. The two argue, but are pulled apart when Santini attacks Fox. She manages to escape, and Sherman's men are intercepted by SO19. Back at Sun Hill, Fox realises the keys in Hagen's possession are Jessica Orton's - and she arrests Santini for m

Superintendent Tom Chandler reads out the names of the dead and injured whilst trying to maintain dignity in the face of the public and the press. Sergeants June Ackland, Matt Boyden and Craig Gilmore are left discussing the unenviable task of speaking to the families and loved ones of their fellow officers. The boys make their excuses and a grief stricken June is left with to make the calls on her own. DC Danny Glaze convinces himself that if he'd spoken out against DS Vik Singh's indiscretions in the first place, none of this would have spiraled out of control like it has. He's determined to track down their prime suspect Jeff Simpson and enlists DC Duncan Lennox, saying he's determined to prove him guilty with or without Duncan's help. They search but Simpson knows they can't pin anything on him and arrogantly waits for them on the bonnet of Duncan's car. Meanwhile DC Mickey Webb's grief becomes unbearable. Superintendent Tom Chandler quietly suggests to DCI Jack Meadows that Mickey

Becka Davis is found upset and she later tells Mel she was assaulted in her own home. Jeremy Williams is questioned about the assault and it is discovered that somebody has been pretending to be her on the Internet. Smithy works undercover to expose a gun running outfit.

Start of the observation. Burnside briefs the men. The Cleghorns think they are involved because of their breakin. Ted and Mike nearly catch the burglars responsible for the Cleghorns breakin but they can't find their shoes. June would have liked to be involved but gets sent to a house where the woman claims her husband has threatened to kill her. He is out but June discovers a radio scanner. He was turned down for the force. June follows him. June is attacked herself in the cemetry after helping another attack victim.

Boyden deals with a frail old man brought into custody accused of attempted murder.

Beech's involvement with rival racketeers becomes more complicated.

Deakin's surveillance on convicted kidnapper Frank Tully's release from custody is immediately blown out when Tully spots them, revealing his already released partner in crime told him he was also under surveillance. Deakin then confronts his partner, Richard Hackett, demanding information on a missing ransom payment from a kidnapping 8 years earlier. Deakin sends Holmes undercover as Hackett's girlfriend, but when they set up an observation, Tully pulls a gun on Hackett and Holmes after discovering there is no money in their safety deposit box. Tully is arrested when Hackett reveals the gun is empty, and suspicion turns to bank manager Roger Carlson, who decided to go on holiday the day of the raid. However, when all he is found with is a small bag of heroin in customs, they discover he may have been framed for someone else to steal the money without Hackett or Tully's knowledge.

A suspected armed robber dies after his car crashes during a chase with police. He is identified as Alain Savoie, a French national, and the body of an English woman is found in the boot of his stolen car. The woman is identified as Carol Archer, and scorch marks on her back indicate she was electrocuted in her bathtub, and Savoie was trying to dispose of the body. According to Carol's mother, Carol's husband Peter was in France looking for her. DI Chris Deakin, a fluent Francophone, suggests they send officers to interview Savoie's sister in France. DCI Jack Meadows insists on making the trip himself, and Deakin suggests he take DC Rod Skase with him. Once they are on the ferry, Meadows and Skase realise neither of them can speak French. With some trouble they manage to find their hotel, and despite the language barrier, Meadows clearly hits it off with the landlady Claudette. CID hear that Peter Archer is headed back to England, but he does not board the ferry, and Interpol reports t

Insp. Monroe is skeptical but cautious when a young woman, Emma Crawford, rings Sun Hill and says she thinks her boyfriend may have hidden a bomb in the station. At Emma's flat, Ackland and Stamp find bomb-making equipment and a faxed warning due to be sent on a timer. PC Carver discovers a suspiscious paint can hidden in the ceiling - enough to trigger the evacuation of the station and the calling in of the Bomb Squad. The suspect, Ben Wallace, has been in trouble with the police before, and he is apprehended by DCI Meadows when he returns to the flat. As the Squad begin defusing the bomb, Ackland and Stamp visit Ben's parents whom he despises. The bomb is dismantled and the station declared safe, but Ackland and Stamp watch in horror as Ben's father is killed by a car bomb planted by his son.

The operation appears to be in jeopardy again when Petrit declares that he is going in search of his missing sister. Following a lead from a girl at a café, he and Carver visit a pool hall, but have no joy with the doorman. Page meets up with Cullen to give him an update, and tells him that she is convinced that they are being set up for extortion by Berisha. Her suspicions are later confirmed when Berisha presents Quinnan with a bill for excess staff. Initially, he refuses to pay, until Berisha starts to strangle him, watched by a helpless Webb and Lennox. A determined Petrit plans to return as a punter to the pool hall where his sister may be, which is identified as a brothel.

Stamp and Keane race into action after finding Smithy's IRV on its side following the assault by another vehicle. Back on the estate, a full blown riot breaks out, orchestrated by Raheem Woods and other members of the Creekside Boys. Roberts finds himself attacked and abducted by the street thugs, leading to a daring rescue to shut the riot down. Late evidence changes the entire context of the case, but with the trial falling apart, can they secure justice for Carly in time?

Callum is determined to catch the bomber but the team receive a message saying another bomb will be achivated in 3 hours. The bomb is traced to a mother taking her children to school. Mickey manges to get her to safety,but when Callum goes back to the car to save her baby the bomb goes off.

Smithy continues to work undercover and finds himself getting in deeper with Darren Cutler, Kieran Wallace, and Tommy Rose. Darren soon works out that he might have been crossed though.