List of Line of Duty episodes

Line of Duty is a British police procedural created by Jed Mercurio. The series stars Lennie James (series 1) and Keeley Hawes (series 2-3), and features an ensemble cast including Martin Compston, Vicky McClure, Adrian Dunbar, Craig Parkinson, Neil Morrissey, and Daniel Mays (series 3). To date, seventeen episodes have aired.

Series overview

Series		Episodes	Originally aired		DVD release date	Ave. UK viewers (millions)
			Series premiere	Series finale	Region 2
	1	5	26 June 2012	24 July 2012	3 February 2014	3.80
	2	6	12 February 2014	19 March 2014	24 March 2014	3.43
	3	6	24 March 2016	28 April 2016	2 May 2016	5.42[1]

Episode list

Series 1 (2012)

The first series of Line of Duty – consisting of five episodes – premiered on 26 June 2012. The series focuses on five main characters: DCI Tony Gates (Lennie James), DS Steve Arnott (Martin Compston), DC Kate Fleming (Vicky McClure), Superintendent Ted Hastings (Adrian Dunbar), and DS Matthew Cottan (Craig Parkinson).

No.	Title	Directed by	Original air date	UK viewers (million)[2]
1	"Fahrenheit"	David Caffrey	26 June 2012	3.76
A counter-terrorist police raid kills an innocent man after mistakenly raiding the wrong flat. DS Steve Arnott refuses to take part in a cover-up. He is transferred to AC-12, an anti-corruption squad led by Superintendent Ted Hastings. Hastings informs Arnott that his first investigation will focus on DCI Tony Gates, the senior officer of TO-20, a unit of Central Police CID, who has just been made Officer of the Year. Hastings has received a tip-off that Gates has a suspiciously high clearance rate due to "laddering" – a process in which a number of different charges are placed on the same defendant to increase an officer's number of successful cases. Initially, Hastings interviews Gates on a minor charge – accepting a free breakfast for apprehending a mugger outside of a local cafe. Meanwhile, Gates offers advice to his lover, Jackie Laverty, after she claims to have hit a dog after drink driving on her way home from a works do. Gates initially offers to help her cover up the incident, by faking a break-in at her home. However, when DS Cottan informs him of the cases that have come in overnight during the morning briefing, he discovers that Jackie actually killed a person during the incident, and not a dog as she claimed. Gates urges her to come clean. Meanwhile, Kate Fleming, currently assigned to divisional CID, approaches Gates and asks if she can join his team. He suggests she come out for drinks with the team to see how they get along, unaware that she is secretly working for AC-12. Meanwhile, DS Leah Janson informs Gates that crime statistics on the Bogg estate are on the rise once more, so Gates assigns TO-20 to investigate. Surveillance reveals that two suspected drug dealers are operating out of a derelict house. Gates asks his team to take turns keeping an eye on the property. Laverty comes into make a statement about the hit and run to an intelligence officer, but fails to disclose her part in the victim's death. When the victim is identified, Gates manages to gain access to the computer records, and deletes the missing persons report which identifies the victim – but not before Arnott manages to take a look.
2	"Lost"	David Caffrey	3 July 2012	3.84
Gates continues his investigation into the double murder of the two suspected drug dealers, and interviews a less than cooperative witness – whom he forces to talk by threatening that, even if he does not talk, he will be labelled a police snitch. Dot and Deepak apologise for leaving the surveillance early. Meanwhile, Simon and Karen respond to a silent alarm at a block of flats and catch a burglar in the act. Leah interviews him, and during interrogation he also confesses to a number of other offences. Meanwhile, Arnott ponders why Gates has taken on the case of the hit and run. Whilst interviewing waitress Nadzia, she informs him that Gates' breakfast companion was tall, slim and dark-haired, and Arnott suspects she may have been describing Laverty. A search on the police database reveals a number of burglaries committed by the offender caught by Simon and Karen were on properties owned by Laverty Holdings PLC. Arnott visits a hairdresser's that was burgled and suspects that Laverty may be running a money laundering scam. Back at the murder scene, the team realise that the attackers cannot have found what they were looking for, but upon discovery of a secret hiding place where they suspect the drugs may have been stashed, they find it has been emptied. Meanwhile, Gates confronts Laverty over the death of her accountant. She tells him that her plan was to expand her business and that he disagreed with the idea, but Gates realises that he discovered that she was laundering money and threatened to tell the police. Gates arrests her, but on the way to the police station she persuades him to release her. Meanwhile, another drug dealer is found dead on the estate, but Gates is nowhere to be found. Kate realises that Gates has disappeared and informs Arnott. Back at Laverty's house, she and Gates engage in another passionate encounter, until masked intruders force their way in. Gates is knocked unconscious, Laverty is murdered, and the unconscious Gates's fingerprints are placed on the murder weapon.
3	"No Criminal"	David Caffrey	10 July 2012	3.80
Arnott speeds to Laverty's house following a tip-off from Fleming, only to find Gates supposedly searching the property, claiming that he has come to arrest Laverty. Whilst at the property, Gates tampers with evidence, hiding his whisky glass and wiping his prints from the bottle just as his team arrives. Arnott demands that Forensics dust the table for prints in the hope of proving that Gates was at the property before Laverty disappeared. Hastings and Arnott haul Gates in for questioning. Gates confirms that Laverty was an old flame, but he denies all knowledge of the money laundering scam. Gates flounders when Arnott asks him how he managed to park his car on Laverty's drive unless she let him onto the property, a hesitation which Arnott suspects is a sign of guilt. Hastings informs Gates' senior officer that he is to be taken off the Laverty case. Fleming looks at CCTV from the night of the murder of the two drug dealers. She finds video footage which suggests that the killers circulated the area for some time in a car on false plates until Dot and Deepak left. Meanwhile, Gates tries to dispose of the whiskey glass from Laverty's house. Fleming receives a call from uniform to say that the cloned car has been spotted, and Gates and Morton give chase. During the pursuit, Gates is kidnapped and taken to a warehouse where he is shown Jackie Laverty's body and is told to stay quiet, or the knife with his fingerprints on will be handed in to the police. A dogged Arnott acts on a tip-off to say the whiskey glass is hidden in a storm drain – a fact which Gates reveals he falsely told Deepak, supposedly confirming Deepak is the mole leaking information to AC-12. Meanwhile, Arnott discovers his colleagues from the armed raid have accused him of messing up the orders, which resulted in the death of an innocent victim. Racked with guilt and his inability to see past his colleagues' betrayal, Arnott sends a text to Fleming and Hastings reading "I'm no longer the man for the job. Gates has won."
4	"Shut Out"	Douglas Mackinnon	17 July 2012	3.87
Fleming suggests to Arnott that the link between Laverty's money laundering scam and Gates may be his children's school fees. Arnott visits the school, who later confirm that Laverty paid the deposit and the first full term in cash. Arnott agrees to return to AC-12. Meanwhile, Hastings decides to bring in the rest of Gates' squad to interrogate them over the 'laddering' charge. Morton refuses to comment, Fleming sticks to her cover and decides to back up Gates, but during questioning Hastings interrogates Cottan about the night of the surveillance on Greek Lane, and he claims that Gates ordered Deepak and him to end surveillance, unaware that this would create a prime slot in the timeline for the killers to strike. Meanwhile, forensic evidence at the crime scene and Arabic books belonging to the victims leads Gates to cook up a story regarding a possible terrorism plot, allowing him to wind up Arnott about the armed raid in which he failed to capture a terrorist cell. Meanwhile, Gates tries to find the location where Jackie Laverty's body is being kept. He receives another call from 'Tommy', who informs him that Arnott has been poking his nose into Laverty's businesses, causing him to lose profits. 'Tommy' informs Gates that he wants Arnott out of the way. Hastings and Arnott inform Hilton that they have a witness who claims that Gates controlled the sequence of events to allow the murder of the two drug dealers. Gates finds the location where he was held, but Laverty's body has disappeared. Morton catches Fleming with two phones and realises she was the real AC-12 mole. He assaults her and drives off to find Gates. Arnott receives a phone call from the owner of the hairdresser's claiming he has information linking Gates to the gang. He sets up a meet, but when Arnott arrives he finds Gates colluding with the gang. Before he can escape, he is ambushed and tied to a chair, and his fingers are placed in a vice. Gates drives away, realising there is no way out.
5	"A Better Way"	Douglas Mackinnon	24 July 2012	3.72
Gates returns to rescue Arnott from the hands of his torturers. Arnott, who is convinced that Gates is innocent of the murders and believes Gates can lead him to the killers, lies to Fleming and tells her that Gates did not play any part in his kidnapping. Meanwhile, with her cover blown, Fleming is forced to leave TO-20, but not before Morton expresses his disgust. Cottan is assigned as deputy SIO on the triple murder case, while Arnott's former counter-terrorism Chief Inspector is brought in to oversee the operation into apprehending the suspects. Fleming interviews Ryan, who denies any knowledge of 'Tommy' or the murder of Jackie Laverty. He does, however, reveal to Fleming that it was Gates who rescued Arnott. Fleming, upset that her colleague has lied to her, informs Hastings. Meanwhile, Arnott uses Morton to set up a midnight rendezvous with Gates. Gates tries to convince Arnott that he has never 'crossed the line', even once, and that he was forced to turn rogue and did not have any choice in the matter. Arnott persuades Hastings to let him use Gates to get to Tommy. Hastings agrees to put a tap on the phone network used by Tommy until one of his many phone numbers is re-activated. Arnott primes Gates, who convinces his wife to let him spend one final hour with his children. When the phone number is re-activated, Gates, Arnott and Fleming trail Tommy to the Edge Park golf club. Gates arrests Tommy. Under interrogation, Tommy reveals that his boys were responsible for the murder of Jackie Laverty and also took out the three drug dealers. Tommy claims that the murders were committed by 'an inside man, someone special to him' who 'always follows orders' and who would admit to them if he forced him to. As Arnott and Fleming catch up with them, Gates realises that his career is over and decides to commit suicide, telling Arnott to inform his wife that he was killed in the line of duty. After Tommy is arrested, Cottan has a quiet word with him. Tommy says, 'You tell me how I'm going to play this one', to which Cottan replies, 'Offer them all the information you can and plead immunity', seemingly confirming that Cottan is Tommy's inside man, later revealed as 'The Caddy', having been recruited as a teenager when he caddied for Tommy at a local golf club. In an epilogue, Gates's family receives a death-in-service benefit of £107,000 plus a pension for life. Arnott and his former counter-terrorism colleagues are acquitted of all charges. The evidence obtained on Tommy is never used, and he is put in the witness protection system. The case against Gates is closed.

Series 2 (2014)

The second series of Line of Duty – consisting of six episodes – premiered on 12 February 2014. The series focuses on five main characters: DI Lindsay Denton (Keeley Hawes), DS Steve Arnott (Martin Compston), DC Kate Fleming (Vicky McClure), Superintendent Ted Hastings (Adrian Dunbar), and DI Matthew Cottan (Craig Parkinson).

Series two received even better reviews than its predecessor,^[3] despite lower viewing figures,^[4] and was ranked the best television drama of 2014 by The Observer.^[5]

No. Overall	No. in Series	Title	Directed by	Original air date	UK viewers (million)[2]
6	1	"Status Zero"	Douglas Mackinnon	12 February 2014	2.74
A police convoy escorting a civilian under a witness protection scheme is attacked. The witness is hospitalised and all police officers are killed – with the exception of Inspector Lindsay Denton, who organised the operation at very short notice and who only informed DCC Dryden. Ted Hastings asks Steve and Kate to investigate Denton, but Kate initially asks not to take part. She explains that she trained together with Jayne Akers, one of the dead officers, but she has also been having an affair with Jayne's husband, Rich. She is replaced by Georgia Trotman, an ambitious but less-experienced officer who is troubled that the team are treating Denton as a suspect and delving into her finances. However, she and Steve quickly grow close, while Hastings tries to keep up appearances with his estranged wife. Denton, shunned by her fellow officers, is transferred to a missing persons unit, and Kate, undercover once again, becomes her assistant. Kate follows Denton to the nursing home where her mother lives and sees Denton ring the hospital where the injured witness is being treated. Georgia and Steve race to the hospital and confront a man disguised as a nurse. Steve is knocked unconscious; Georgia, who sees the killer's face, is thrown out of a window to her death, and the witness is killed.
7	2	"In the Line of Duty"	Douglas Mackinnon	19 February 2014	3.21
Steve discovers that a nurse on the witness's ward, Claire Tindall, was threatened into giving the killer access by a man she knows as Joe, but whom she is unable to identify. Denton begins her work in missing persons with the case of a vanished teenager named Carly Kirk. As they work together, Kate attempts to gain Denton's confidence, but Denton sees through this, assaults Kate and steals her phone. Denton is interviewed again by AC-12 and claims that she rang the hospital to ask that the witness exonerate her, but the team do not believe her and Hastings arrests her for conspiracy. At this point Denton turns the tables and gives evidence, on the record, that Steve made an unofficial romantic visit to Claire, Hastings has financial problems (something he previously cited as making Denton vulnerable to bribery) and Kate's cell phone has an "interesting" call history (alluding to her affair with Richard Akers). Meanwhile, a story surfaces in the press that DCC Dryden took penalty points for his wife when she committed a driving offence. In a parallel sub-plot, Denton has a dispute with her alcoholic neighbour. The neighbour plays loud music late at night, and accepts cash in return for not doing so. One evening Denton snaps and strikes her with a wine bottle, which she then wipes down and disposes of. When the neighbour reports the attack, Denton flatly denies it. Again the music disturbs Denton, who finds her neighbour's door open and the woman asleep, while a chip pan is heating up. On reflection, Denton turns the gas off, takes the money and leaves.
8	3	"Bail Hearing"	Douglas Mackinnon	26 February 2014	3.34
Denton is remanded in custody, where she is victimised by both staff and prisoners, having her hands badly burnt and warned not to speak to the authorities. Hastings requests witness protection records from Dryden, allowing AC-12 to discover the identity of the dead witness: Tommy Hunter, the gang leader previously arrested by Tony Gates. Cottan believes that the mole who betrayed the escort was in fact Jayne Akers, the liaison officer. Kate visits Denton, who knows about Kate's affair with Jayne's husband, which Cottan also suspects. Denton's accusations also cause friction between Hastings and Steve, and Dryden's driving offence continues to occupy the press. To draw attention away from himself, Dryden leaks the information that Denton is the officer under investigation. At the site where Denton stole Kate's phone and blew her cover, Kate discovers a body, apparently that of the missing Carly. She re-interviews Denton, who claims that Dryden, a married man, had an affair with her and has set her up. Kate discovers that Dryden and Denton did previously work together, lending some credence to this story. Cottan discovers from forensic accountants that Jayne Akers received a large sum of cash shortly before she died.
9	4	"Breakfast"	Daniel Nettheim	5 March 2014	3.46
Steve and Kate persuade Hastings to bring Dryden in for questioning but find the DCC uncooperative and frosty. They face a further problem when the Major Violent Crimes team bring in Richard Akers before they can do so, as Steve mistakenly assumed that Richard was unaware of his wife's corruption and so decided he was not a priority. When they do get to interview Akers, he reveals that Jayne kept recordings of Tommy as leverage and stored them at a PO Box. The recordings show Tommy threatening to inform on various parties, including corrupt police officers "from the two-faced bastard right down to The Caddy", unless they ensure his witness protection and immunity are maintained. A recording of Dryden publicly criticising the immunity Tommy and others like him receive suggest he is the corrupt officer in question, and AC-12 begin seeking the identity of 'The Caddy'. Denton is granted permission to visit her dying mother at her nursing home, but on the return journey Denton's prison van is run off the road. Fleeing for her life, Denton finds herself confronted by two corrupt police officers, including the man who murdered Georgia Trottman.
10	5	"Taste of Freedom"	Daniel Nettheim	12 March 2014	3.73
Denton manages to escape her kidnappers in violent circumstances that lead to the death of one and the hospitalisation of the other, and AC-12 find themselves forced to decide where their loyalties lie between Denton and Dryden. With the evidence mounting against the latter, the discovery of pictures showing Dryden and 15-year-old Carly Kirk in a compromising situation is the final nail in the coffin, resulting in Steve and Kate finally arresting the DCC. However, when presented with AC-12's evidence, Dryden still strongly maintains he is being set up. Meanwhile, Cottan approaches DC Morton from his old team. Morton is the officer who sold the story about Dryden's driving offence to the papers, and Cottan blackmails him into falsely saying Jeremy Cole, the deceased kidnapper, was nicknamed 'The Caddy' by fellow officers.
11	6	"Rest in Peace"	Daniel Nettheim	19 March 2014	4.12
Dryden claims that Denton was at the car park when he was photographed in the car with Carly. Steve gets closer to Denton but reveals to Kate that he is undercover, as she was earlier. Steve finds the pay-off money hidden among the possessions Denton took from her mother's room. A flashback shows the events leading up to the ambush. Denton follows Dryden to the reception, where Carly meets and attempts to seduce him. Denton has a brief conversation with her in the ladies' cloakroom and then follows Carly and Dryden to the car park, where she sees Carly fellate Dryden and that she is working for Tommy. Some days later, Denton approaches Tommy but is surprised to find him accompanied by a police detective – Akers. Akers visits Denton at her home to request help in handing Tommy over to his criminal associates, who want to kill him out of fear he will inform on them in witness protection. With a pay-off, and appealing to Denton's desire to protect Carly from her pimp and abuser, Akers persuades her to assist in the handover. In reality the handover is being planned by Cottan, the mastermind who is known only to Akers and Tommy. He orders two corrupt officers to ambush the convoy, who follow it using a tracker placed on Denton's vehicle. Akers and Tommy are both killed to protect Cottan's identity, Denton is left alive to take the blame. Further details are revealed in an epilogue. The buried body is not Carly's, who has fled the country unknown to the authorities and criminal parties. DS Prasad, who carried out the ambush and kidnapped Denton, gives evidence against her in return for complete immunity from prosecution. DC Morton is not suspected of any wrongdoing and will retire in a year on full pension; he continues to sell confidential information to the press. DCC Dryden is given a suspended sentence for perverting the course of justice regarding his wife's speeding ticket and resigns from the police force. Denton is convicted of conspiracy to commit murder and given a life sentence. Cottan is asked to remain in AC-12. Major Violent Crimes continue to investigate who organised Tommy's murder, but no police officers beyond Denton are suspected.

Series 3 (2016)

The third series of Line of Duty – consisting of six episodes – premiered on 24 March 2016. The series focuses on five main characters: DI Lindsay Denton (Keeley Hawes), DS Steve Arnott (Martin Compston), DC Kate Fleming (Vicky McClure), Superintendent Ted Hastings (Adrian Dunbar), and DI Matthew Cottan (Craig Parkinson). Sergeant Danny Waldron (Daniel Mays) appeared in two episodes.

No. Overall	No. in Series	Title	Directed by	Original air date	UK viewer (millions)[1][6]
12	1	"Explanations"	Michael Keillor	24 March 2016	3.54
Sgt. Danny Waldron and his team of armed officers are deployed to detain Ronan Murphy, a suspect wanted in connection with a plot to commit a gangland execution. Waldron orders a 'hard stop' on the suspect's vehicle, forcing the suspect to decamp into a nearby housing estate. Waldron gives chase, but catches up with him long before his team arrive. Waldron decides to shoot the suspect in cold blood, despite him having already surrendered his gun, and fakes the scene to make it look like he opened fire before he was shot. When Waldron's team arrive, he orders them to discharge their weapons. Under interrogation from AC-12, Waldron looks to have an answer for everything, until DS Arnott's line of questioning into his private life begins to spook him. Hastings agrees to send Fleming undercover as a new member of Waldron's squad in an attempt to uncover the truth. Waldron's team are tense as a result of being bullied into collaborating with Waldron, and Fleming identifies PC Harinderpal 'Hari' Bains as a possible informer, but Bains refuses to testify. After pressure from AC-12 department lawyer Gill Biggeloe, Waldron's team are returned to active duty along with Fleming. On their first call, they are tasked with raiding a house where drugs are kept. Waldron steals an illegal firearm then stops Fleming from aiming her gun at a child who surprises them. Waldron demands that Fleming transfer out of his squad. Waldron lingers outside Bains' house with the stolen gun, but leaves when spotted. He later spies on Ronan Murphy's funeral. He follows Linus Murphy, one of the mourners, breaks into his house, and holds him at gunpoint, implying as he does so that Ronan and Linus were part of a group who abused him as a child, and that he killed Ronan for revenge. He murders Linus off-screen and returns to his flat, where he leaves a list of names including Ronan, Linus, and Tommy Hunter in an envelope addressed to Arnott. Waldron's team raids another drug house, where he orders Fleming to stay behind while the rest of the team search upstairs. Fleming hears shots fired, and rushes upstairs to find the other squad members standing around Waldron, who has been shot in the neck.
13	2	"Man Down"	Michael Keillor	31 March 2016	6.02
Kate Fleming attempts to provide first aid to the wounded Sgt. Waldron, who dies in the ambulance. The remaining members of the team, PC Rod Kennedy, PC Hari Bains and PC Jackie Brickford, are interviewed by AC-12 and claim that Waldron shot himself despite their attempts to stop him. Hastings attempts to arrest them, but Gill Biggeloe convinces him to rescind the arrest. The police search Waldron's flat, finding Linus Murphy's dog (who Waldron took with him after the murder to help lead the police to Murphy's body) and DI Cottan discovers a box containing the stolen gun, a photograph of a young Waldron and other boys alongside Ronan and Linus Murphy, and the envelope, addressed to Arnott, containing Waldron's list. Cottan steals the list. Arnott agrees to take over the investigation of Waldron while Cottan focuses on his colleagues. Arnott locates Linus's home and finds his tortured and decapitated body, then finds the head in a storage room rented by Waldron. Waldron's team-mates find themselves suspected by their colleagues, and Fleming pressures them further by suggesting that she knows they murdered Waldron, and indicating that she will tell AC-12 about a radio call Bains made to Waldron moments before his death, which was not included in the reports. Meanwhile, Lindsay Denton has appealed her conviction for conspiracy to murder Tommy Hunter and Arnott is called as a witness. He denies having a sexual relationship with Denton in court, but the suggestion puts strains on his relationship with his girlfriend, DS Sam Railstone. Scared by pressure from Fleming, Kennedy demands to meet with Bains in a disused warehouse, blaming Bains for their situation, resulting in a brief physical confrontation. Denton claims in court that she had sex with Arnott. The next morning, Kennedy's body is found hanged in the warehouse where he confronted Bains. Brickford and Bains meet, and appear the next morning to alter their statements to AC-12. They now claim that Kennedy shot Waldron, and Brickford confesses that she had a relationship with Kennedy until some months earlier, when they broke up after she had a one-night stand with Waldron. Bains receives a package containing a phone, and receives a call from someone who congratulates him on his deception.
14	3	"The Defence Calls..."	Michael Keillor	7 April 2016	5.73
Hastings authorizes Fleming to begin surveillance of Hari Bains. She watches him meeting with Jackie Brickford; when Arnott interviews Bains' superior, Bains panics and is observed calling his contact from a payphone. Fleming asks Cottan to organize a second examination of Rod Kennedy's body, which Cottan intentionally neglects to do. The photo of Waldron and Ronan Murphy is traced to his time in Sands View boy's home. Arnott identifies Joseph Nash, another boy in the picture, and interviews him. Nash explains that Linus Murphy was the caretaker at Sands View, that both men abused boys at the home, and that boys at the home were sexually abused by other men both at Sands View and at private parties. He identifies then-Councillor Dale Roach, but Roach is unable to stand trial as the result of a stroke. Brickford visits Fleming to find out what AC-12 has been asking her. Fleming reveals that Bains has been making phone calls, seemingly to Brickford. Brickford confronts Bains, who cannot explain the calls. Brickford returns to AC-12 and confesses that Waldron was shot in a struggle that Brickford and Kennedy were involved with, only Bains saw how it began. Bains claimed that Waldron had aimed at him, and Bains grabbed the gun in self-defence. Brickford also confesses lying about Ronan Murphy's death. Hastings has Brickford's police contract terminated and warns her she may yet be charged. Meanwhile, Arnott orders a second post-mortem on Rod Kennedy's body, which indicate he was murdered. AC-12 moves to arrest Bains and the firearms unit are deployed to arrest him, but his contact (revealed to be Cottan) warns him and he escapes. He travels to the warehouse where Kennedy was hanged, and finds Cottan (unaware that Cottan is his contact). As the firearms team approach, Cottan handcuffs and injures himself to fake a fight. Bains is arrested and the police find a noose, supporting Cottan's story that Bains was attempting to hang him. Lindsay Denton's trial reaches its conclusion – the jury finds her not guilt of conspiracy to murder, and she is released with time served. She tells Arnott she forgives him outside the courthouse. Cottan is congratulated by his colleagues, but the unregistered phones in Bains' home suggest that he was acting on orders, and as Cottan watches news footage of Denton's release, a number of mobile phones in his house begin to ring simultaneously.
15	4	"Move On"	John Strickland	14 April 2016	5.55
Lindsay Denton is taken to AC-12 where she demands a formal apology. She reveals that she has a recording of her and DS Steve Arnott in a compromising situation, that she will use against him as evidence of perjury if they do not comply with her requests. Denton is forced to work as a supermarket cleaner and later entraps an exploitative parole sponsor trying to pressure her into sex. Arnott – who is losing confidence within the department – eventually meets with Denton and asks for help in finding the link between Sands View and Tommy Hunter. DI Matthew Cottan is awarded with a commendation for his perceived bravery arresting a corrupt police officer, Hari Bains. He then proceeds to tell Gill and DC Kate Fleming that he is concerned about Steve's behaviour that he is carrying a firearm in his jacket. Bains confesses to killing Danny Waldron on the demands of his unknown contact, but insists he did not murder Rod Kennedy. Steve and Kate confront Ted saying they believe they should question a retired officer on the subject of allegedly reporting to a mother that a sexual abuse complaint of Dale Roach was both dealt with as well as Roach being charged and sent to prison. The mother saw Dale Roach in the newspaper some time later so knew she had been lied to. The death of a former social worker at Sands View, ruled as a suicide, is reinvestigated due to allegations that he attempted to report the abuse to police and may have been murdered to prevent his case being pursued. They eventually interview former Vice chief superintendent Fairbanks, who claims to remember no details of the case. He and Hastings share a handshake that Arnott identifies as being Masonic. Cottan meets with former colleague Nigel Morton and threatens to derail his pension if he does not hand over the last known evidence of Cottan's true allegiance – a mobile phone and SIM card with records of calls made to Hunter. Morton then tells AC-12 that the Caddie is probably still alive, leading Cottan to create a presumptive profile which he deliberately engineers to fit Arnott. Morton hands the phone and SIM to Cottan in a car park (where Cottan was prepared to kill him if he had not complied), but it is then revealed that it was a duplicate and Morton still has the real items hidden in his car.
16	5	"Commendation"	TBA	21 April 2016	5.72
Cottan continues to stack the deck against Arnott, first by pressurising PC Maneet Bhandra to hold off on key forensics (specifically the envelope found in Danny Waldron's flat), and then by spreading rumours surrounding Arnott's conduct, including telling Fleming that he has a lead linking Arnott to Lindsay Denton's bribe money. Arnott is eventually suspended by a hesitant Hastings, to whom he reveals the redacted file that would have linked Ronan and Linus Murphy to Tommy Hunter. Hastings challenges Gill on this but is rebuffed. Meanwhile Fairbanks is called in to interview and maintains his ignorance as he is presented with images of alleged abusers, such as councillor Dale Roach and real-life BBC DJ Jimmy Savile (who is not identified by name in the show). Joseph Nash is shown a photograph of Fairbanks, ostensibly to identify him as an officer that had overlooked accusations, but his reaction suggests that Fairbank was one of the abusers. Arnott continues to meet with Lindsay Denton as they investigate the possibility of Danny Waldron hiding another copy of his list of abusers. Denton realises the list is likely kept digitally, so she tricks Arnott into pursuing a false lead while she, after stealing Arnott's pocketbook, goes to an internet cafe to access Waldron's emails. She finds a photograph of the list in his drafts folder and transfers it to hers as insurance. Outside, Cottan – who has been following Denton – summons her into his car, revealed to be DS Arnott's service vehicle with fake license plates, and drives her to an industrial facility demanding at gunpoint that she hand over the information, offering money for her obedience. Denton, staying true to her morals as a police officer, defiantly emails the list to Hastings. Cottan murders Denton but is too late to prevent the list being sent.
17	6	"Getting to the Truth"	TBA	28 April 2016	5.93
Patrick Fairbank is arrested and interviewed on new information submitted by Joe Nash during an identity parade. During the interview, Hastings receives the list sent by Lindsay Denton which identifies Fairbank as one of the abusers. Meanwhile, Arnott awakens to find his pocket book missing and his car stolen. As he reports the car missing, Hastings attends a call to a dockers yard where the body of Lindsay Denton has been discovered in Arnott's car. Arnott is arrested on suspicion of murder. During questioning, evidence identifying Arnott as 'The Caddy', such as money from Lindsay's Denton's bribe and the mobile phone he used to contact Hari Bains, are shown to have been found in Arnott's gym bag. Arnott also realises that the evidence records relating to his hiring of a firearm have been doctored to suggest he did not return it. Arnott realises that somebody within the department has set him up, but has no way of proving it. Cottan then reveals, much to the surprise of Hastings and Fleming, that he has suppressed the evidence found in the envelope left to Arnott by Danny Waldron, and that the evidence is in fact a golf tee, supposedly confirming that Arnott is 'The Caddy'. Fleming informs Hastings that she has been carrying out an undercover operation into the officers of AC-12 under the orders of a superintendent from AC-3. She highlights inconsistencies within Cottan's line of questioning against Arnott. Having spoken with DS Nicola Rogerson, she identifies that Cottan was the one who fed AC-12 the doctored file on Ronan Murphy. Hastings confronts Gill Biggeloe, who confirms that it was Cottan who gave her the file. Maneet later reveals to Fleming that it was Cottan who told her not to inform Arnott of the forensic findings of the envelope found in Waldron's flat. Fleming also uncovers CCTV which confirms that Arnott's car was being driven on false plates shortly before the time of the murder. Cottan is brought in for questioning. He denies all knowledge of the doctored file and claims that Arnott must have been the one responsible, having previously had a relationship with DS Rogerson. Hastings pressures Cottan on the suppression of the golf tee from evidence, as well as the fact that no blood was found on the tee despite blood being found on both the envelope and the list. Cottan claims that he only removed it to prevent Arnott from becoming aware that he was investigating him. Fleming reveals new forensic evidence against Cottan – fibres from the rope found at Rod Kennedy's murder scene in the boot of his car. Cottan strenuously denies any involvement with Kennedy's murder. Hastings probes him on evidence submitted by Nigel Morton, which suggests that he pressured Morton into wrongly identifying 'The Caddy', and also used a secret mobile phone. Phone records reveal that he previously called Tommy Hunter several times in the months leading up to his death. Fleming presses Cottan on the lead he claimed to have on Arnott linking him to Lindsay Denton's bribe, which Hastings points out could not have been the money in Arnott's gym bag as that was not discovered until after Denton had been killed, the morning after Cottan alleged to have evidence against Arnott. When questioned about his whereabouts on the morning of Lindsay Denton's murder, Cottan fails to provide a solid alibi, and Fleming reveals that he was not at his flat where he claimed he was. Cottan sends a text to three recipients, 'Response', 'Talk', and 'Ride'. An armed officer guarding the interview shoots a fellow armed officer dead, and then fires shots into the interview room, enabling Cottan's escape, and then hands him a pistol. Pursued by an armed Fleming, Cottan is rescued by a getaway car. Fleming manages to shoot the driver and brings the car to a standstill. As she goes to confront Cottan, another passenger fires three shots aimed at her, but Cottan jumps in front of her, taking the bullets. In a final act of redemption, Cottan records a dying declaration that directly leads to Fairbanks being jailed for ten years. The epilogue reveals that Arnott is exonerated, Fleming is awarded for her bravery, and later promoted to Sergeant, Denton receives posthumous recognition for her contributions by the coroner, but is buried with no mourners, and Nigel Morton retires on full pension plus disability benefits. The epilogue also states that Hastings, Arnott, and Fleming remain with AC-12.

Series 4 (2017)

BBC Two have commissioned a fourth series of Line of Duty to be released early in 2017.^[7][8] On May 6, 2016, it was confirmed that the show would be moving to BBC One.^[9]

Series 5 (2018)

A fifth series was commissioned on May 6, 2016.^[9]

References

1. 28 day data
2. "BARB". BARB. Retrieved 16 February 2014.
3. Hogan, Michael (26 February 2014). "Line of Duty review". The Telegraph.
4. Munn, Patrick (27 February 2014). "Ratings:BBC2's Line of Duty Remains Steady". TV Wise.
5. Ferguson, Euan (7 December 2014). "The best British TV Dramas of 2014". The Observer.
6. "Top 30 Programmes – BARB". barb.co.uk. Retrieved 2016-02-11.
7. "BBC Two celebrates 50th birthday with ambitious new commissions". BBC Television. British Broadcasting Corporation. 8 April 2014. Retrieved 31 May 2014.
8. "BBC Two announces Jed Mercurio's Line Of Duty commissioned for further two series". BBC Television. British Broadcasting Corporation. 8 April 2014. Retrieved 31 May 2014.
9. "Line of Duty to move to BBC1 for two more series". Retrieved 15 July 2016.