'Line of Duty' Season 3 refresher — everything you need to know

Line of Duty Season 3 recap.
Here's your Line of Duty Season 3 recap! (Image credit: BBC/World)

Here's our essential Line of Duty Season 3 recap which will help you if you're trying to understand Line of Duty Season 6!

Line of Duty season 3 is one of the most important seasons of TV's hottest crime thrillers. Jed Mercurio's twisty drama has drawn more and more viewers in each year, but season 3 remains one of the best seasons yet.

If you're feeling a little bit lost or you're wanting to jump into one of the biggest shows on TV, here's our recap of all the things you need to know from Line of Duty season 3!

How to watch Line of Duty Season 3

In the UK, you can find all six episodes of Line of Duty season 3 on BBC iPlayer. 

In the US, Line of Duty season 3 is available to watch on a number of streaming platforms including Britbox, Hulu, Amazon Prime Video, and Acorn TV

BritBox is probably the best place to get binging Line of Duty, if you haven't started already. They've just recently snapped up the exclusive US rights to Line of Duty season 6.

Line of Duty Season 3 recap: The main storyline

Line of Duty season 3 focuses on AC-12’s investigation into Sergeant Danny Waldron. Danny and his squad of officers are deployed to take Ronan Murphy into custody. Ronan bails out of his car and Danny chases him on foot to a dead end in a housing estate, executing him in cold blood.

When his team arrive, Danny instructs them all to discharge their weapons and to stay quiet about what occurred, before arranging the scene to look like Ronan Murphy opened fire first on them. Throughout the first episode, Danny spies on and bullies his colleagues to ensure they stick to the story. AC-12 calls Danny in for questioning over the incident, where he remains cool until Steve Arnott (Martin Compston) begins to interrogate his personal life and suggest that Danny won’t get away with what he did.

Kate Fleming (Vicky McClure) is added to Danny’s Squad as an undercover operative and she very nearly shoots a child when deployed on a raid on a drug dealer’s house. Whilst out of sight, Danny finds and takes an illegal firearm from the scene; when they return to the station, he demands Kate is removed from the squad, but she remains at the station.

AC-12 identify PC Hari Bains as the member of Danny’s squad most likely to crack under pressure. Meanwhile, Danny watches Ronan Murphy’s funeral, and then follows Linus, Ronan’s uncle, back to his home. There, he reveals to Linus Murphy that he was the one who murdered Ronan, before drawing the gun he stole earlier and setting about torturing and murdering Linus in cold blood.

Back home, Danny puts a list of names inside an envelope for Steve Arnott. Kate is deployed alongside Danny's squad on another drug raid. When told to remain downstairs, she hears a gunshot. Rushing upstairs, she finds Danny bleeding out on the floor with his three squadmates standing over him. Kate attempts first aid, but Danny passes away in the ambulance.

In Episode 2, AC-12 begin investigating PC Rod Kennedy, PC Hari Bains and PC Jackie Brickford to find out who killed Danny, but all three of them claim Danny shot himself whilst they tried to stop him in a struggle. Ted Hastings (Adrian Dunbar) attempts to arrest them but is stopped by AC-12's departmental lawyer, Gill Biggeloe. After searching Danny’s flat, the police find Linus Murphy’s dog, whilst Dot Cottan finds Danny’s illegal firearm and destroys his list of targets, leaving the envelope addressed to Steve behind — this is only the first time that we see Dot intentionally disrupt the investigation.

Steve agrees to take the lead on the Danny Waldron investigation, leaving Dot to focus on his squadmates. He goes to Linus’ home, finding his tortured and decapitated body, and later finding Linus’ head in a storage room that Danny had rented. Meanwhile, Kate starts putting pressure on Hari, Jackie and Rod to reveal exactly what happened, threatening to report them to AC-12.

Steve's investigation starts being disrupted by an appeal from Lindsay Denton (Keeley Hawes). She is contesting her conviction from season 2, and Steve is called as a witness in court. Here, Lindsay throws him under the bus by claiming the two had sex whilst he was investigating Tommy Hunter's murder. 

Rod Kennedy's body is found hanged the following morning. This prompts Hari and Jackie to change their story. Now, they claim Rod was the one who shot Danny during a confrontation during the drug raid in episode one. Hari then receives a call on a burner phone from an unknown number and is congratulated for his secrecy.

Ted authorises Kate to watch Hari more closely, where she spots him meeting up with Jackie outside of work. Steve identifies Linus, Ronan and Danny in a photo from Sands View Boys Home, and also tracks down another boy in the photo, a now grown-up Joseph Nash. Nash explains that Linus was the caretaker at the boys home, and that both men sexually abused the young boys at the home alongside other high-ranking people from the local area. He names former councillor Dale Roach as one such abuser, but Roach is deemed unfit to stand trial due to his ill health.

Later, Steve interviews Hari’s superior officer. The increased pressure from the investigation finally gets to Jackie Brickford, and she confesses that Danny was actually shot in a struggle that she, Danny and Rod were involved in. 

She claims that Hari is the only one who saw how the struggle happened, but Hari states he only grabbed the gun in self-defence. AC-12 move to bring Hari into custody, but he escapes and is directed to the warehouse where Rod was found by the contact on his burner phone. At the warehouse, he is met by Dot, who fakes a fight with Hari and handcuffs himself before a team arrives and arrests him. Ted congratulates Dot for his bravery.

Lindsay is found not guilty of conspiracy to murder Tommy Hunter and is released from prison. She is taken to AC-12 in episode 4 and demands a formal apology from the department, revealing a recording of her and Steve to support her earlier accusations of Steve’s misconduct. With many officers around the office (including Ted and Kate), Steve is forced into approaching Lindsay for help on the case. Meanwhile, Dot begins spreading rumors about Steve to Kate and Gill Biggeloe, suggesting that he is behaving strangely. 

Eventually, AC-12 uncover evidence that suggests police deliberately mishandled any investigations into Sands View Boys Home, as Nash had suggested the boys had tried to report their abuse before. The apparent suicide of a former Sands View social worker (which AC-12 suspect to be murder) prompts Steve and Kate to go after retired Vice Chief Superintendent Patrick Fairbank, but he claims he can’t remember anything about the case. 

After bribing Nigel Morton into submitting testimony that suggests “The Caddy” is still alive and demanding he hands over the last bit of evidence of Dot’s criminal deeds, Dot finally lays his profile of The Caddy to AC-12. He has deliberately designed it to frame Steve, and he continues to build a case against Steve, forcing Ted to suspend him from active duty in episode 5. Elsewhere, Nash is shown a photograph of Fairbank to see whether he identifies him as one of the officers who overlooked the Sands View boys’ accusations.

Steve continues to look for Danny’s missing list, and Lindsay works out that Danny must have saved a backup digital copy. She sends Steve off on a wild goose chase after stealing his pocketbook, which she uses to break into Danny’s email account as an internet cafe. There, she finds a photo of a list of names (including Fairbank, Ronan and Linus Murphy). 

Dot summons Lindsay outside and takes her to an industrial site in what is revealed to be Steve’s service vehicle with fake license plates. Dot attempts to bribe Lindsay into handing over the list, but Lindsay emails it to Ted from her phone and he shoots her at point-blank range.

What happens in Line of Duty season 3’s finale? 

Dot Cottan in Line of Duty.

Dodgy Dot finally gets his comeuppance. (Image credit: BBC/World)

Line of Duty season 3’s finale is packed with action, and could arguably be called one of the show's best episodes to date!

The feature-length episode starts with Patrick Fairbank being brought into AC-12 on new evidence from an ID parade, and Ted identifies Fairbank as one of the abusers from Danny’s list. 

After reporting his service vehicle missing, Steve is arrested on suspicion of Lindsay’s murder after his car is found with her body inside at a dockyard. During his tense interview with Dot and Ted, Dot continues to bring out more evidence to frame Steve as The Caddy including money from Lindsay’s bribe and the mobile that Dot had used to contact Hari Bains. 

Shockingly, Kate reveals that she’s been conducting her own undercover operation within AC-12 under authority from AC-3. She starts picking holes in Dot’s line of questioning, and she later finds CCTV which confirms Steve’s car was driven with false number plates.

As Ted continues to pressure Dot on his suppressed evidence and Kate brings to light new forensic evidence which connects him to Kennedy’s murder, he is backed into a corner. When questioned about his whereabouts on the morning of Lindsay’s murder, Dot texts the phrase “urgent exit required” to several contacts named “removals”, “talk”, and “ride”. Suddenly, an armed guard shoots the other officer, and fires through the windows into the interview room, allowing Dot to escape. Determined to catch him, Kate grabs a gun and gives chase without waiting for backup.

Dot leads Kate on a merry chase until she manages to successfully shoot the driver of his getaway car. As she moves in to arrest Dot, another passenger attempts to shoot her from the car, but Dot pushes Kate away at the last second. In his final moments, Dot gives his dying declaration to Kate, where he reveals evidence against the OCG that leads to Patrick Fairbank’s imprisonment. 

This evidence is essential to understanding Line of Duty going forward. Although we only see Dot mention Fairbank in his final moments in season 3, Dot’s dying declaration is the reason we’re all still asking “who is H?” His final words will be referred to several times in the show’s later seasons, as it’s Dot who first refers to the mysterious figure called H to Kate Fleming. 

In the epilogue, we learn that Steve is cleared of any charges, and Kate is awarded a commendation and promotion for her bravery. Meanwhile, Lindsay Denton is awarded posthumous recognition for her contribution to the case, even though her burial goes unattended. Finally, we see that Nigel Morton is able to retire with his disability benefits (even though we clearly see he’s been faking his condition). Steve, Kate, and Ted remain at AC-12 to continue investigating police corruption.

Martin Shore
Staff Writer at WhatToWatch.com

Martin is a Staff Writer with WhatToWatch.com, where he produces a variety of articles focused on the latest and greatest films and TV shows. 

Some of his favorite shows are What We Do In The Shadows, Bridgerton, Gangs of London, The Witcher, Doctor Who, and Ghosts. When he’s not watching TV or at the movies, Martin’s probably still in front of a screen playing the latest video games, reading, or watching the NFL.