Line of Duty ending explained

It’s official: Line of Duty is returning for season 7.

For a long time, people have been hoping the popular crime drama from Jed Mercurio would return, ever since it last aired in 2021. Now, the BBC has officially announced that new episodes are happening! Filming with stars Vicky McClure, Martin Compston, and Adrian Dunbar will begin in Belfast in spring 2026.

Jed Mercurio said those involved with Line of Duty are incredibly thankful for the support of its viewers.

We’re thrilled so many of you have watched AC-12 through all six seasons, and we’re excited to be back for a seventh!

So, what can we expect?

In the new episodes, “AC-12 has been disbanded and rebranded the Inspectorate of Police Standards.”

Fighting corruption is harder than ever, and now Steve Arnott, Kate Fleming, and Ted Hastings face their most delicate case yet, according to the show’s description.

Detective Inspector Dominic Gough, a popular and successful officer known for dismantling organized crime groups, is now facing accusations of using his authority to sexually exploit others.

“But is Gough’s case a deliberate distraction from a bigger threat still operating in the shadows?”

Another quiet season of telly, then…

Compston expressed his excitement about returning for another series, calling Line of Duty a career highlight. He emphasized the strong friendships he’s formed with the cast and crew, and shared his eagerness to reunite with the team and reprise his role.

McClure also expressed her enthusiasm, saying she was thrilled Line of Duty was returning and eager to reunite with Jed, Martin, and Adrian. She added that filming would soon begin in Belfast.

The next season isn’t expected until around New Year’s Day 2027—the BBC often launches major shows at the start of the year—so we’re taking a look back at what happened with AC-12 in the last series to refresh your memory.

During the final episode of Line of Duty’s sixth season, AC-12 at last discovered who ‘H’, the mysterious ‘Fourth Man’, really was. However, the big reveal wasn’t shared with the audience at the same moment – viewers were kept in the dark a little longer.

The team spent another agonizing eight minutes shuffling papers, making vague comments, and getting distracted by other topics. Suddenly, Steve exclaimed, “We’ve been wasting time on the wrong things! If this is correct, he’s been right in front of us all along!” (We immediately assumed he was talking about Chief Constable Osborne.) What followed was a quick series of shots showing armed officers arriving at AC-12 and leading an unidentified person inside. Detective Inspector Steve Arnott was seen quickly researching on his iPad, accessing the suspect’s DIR – but the camera conveniently cut away before revealing the interviewee’s name.

The reveal of who was being interrogated in AC-12 – it was Buckells! – was a shocking moment for many viewers. Across the country, fans reacted with disbelief, and you could almost hear a collective gasp as the identity was revealed.

Superintendent Ted Hastings (Adrian Dunbar) was furious, realizing they’d spent the whole time hunting for a brilliant criminal, only to discover the problem wasn’t skill, but corruption. He angrily stated, “We thought we were dealing with a mastermind, but it turns out your failures were actually deliberate wrongdoing.”

So, that was that.

The season 6 finale had a lot happening, so here’s a recap and explanation of everything that went down.

DCI Ian Buckells revealed as H, the “Fourth Man”

Turns out, DCI Ian Buckells (Nigel Boyle) was the mastermind all along! Though, he wasn’t quite as intimidating as everyone expected. He smugly declared, “Oh, so you think I’m an idiot? I’m the one who’s been playing you all!”

Back in 2003, while still a Detective Constable, Buckells investigated a group of corrupt police officers. They deliberately mishandled the Lawrence Christopher case, following orders from Tommy Hunter, to help Hunter’s son, Darren, avoid prosecution. Buckells’ boss at the time, Marcus Thurwell, was the one involved in the corruption, though Philip Osborne, who would later become Chief Constable, was also suspiciously connected to the case.

Following the events of 2003, Buckells surprisingly advanced in his career, despite being unremarkable, as Hastings described it. Even after Tommy Hunter’s death in 2014 and the breakup of the original criminal organization, Buckells continued to leak information to criminals and corrupt police officers. He used an encrypted messaging service to send them details and instructions, with Thurwell helping from Spain by masking the messages’ origin through a Spanish IP address before sending them to the UK. His reason for doing so was simple: money. As Ted put it, Buckells was willing to do anything for the right price.

Buckells told himself he was simply providing information to criminals and letting them take responsibility for the actual violence. He claimed, “It was the gangs who did it! I just passed on the information. I didn’t plan any of it.” He believed there was nothing wrong with taking the money and using it to buy luxury homes.

So, what about Jo Davidson? She had no idea Buckells was the one really in charge. She worked right next door to him, but believed he was just a clumsy, ineffective officer she could blame for her own corrupt behavior. And for a while, she pulled it off – much to Buckells’ confusion.

Throughout season 6, Jo consistently believed she was communicating with Patrick Fairbank (George Costigan) via her laptop, but she was actually talking to Buckells. This misunderstanding stemmed from a cruel lie Tommy Hunter told a young Jo: he falsely claimed Patrick Fairbank was the man who assaulted and fathered a child with Jo’s mother, Samantha Davidson. Because Samantha had recently passed away, she couldn’t refute this claim. Jo held onto this belief until AC-12 revealed the shocking truth: Tommy wasn’t just her uncle, but her biological father.

Tommy likely lied about Jo’s father, claiming he was a man named Fairbank, as a way to manipulate and control her. He pushed her to join the police force in the late 1990s while Fairbank – a highly-ranked, corrupt officer and known child abuser – was still active, and likely giving orders to other officers. Even after Fairbank retired, was arrested, and convicted, Jo continued to believe her abusive father was still pulling the strings, first from his home and then from prison.

When she finally revealed information about Fairbank to AC-12, she believed she was identifying a key figure – and AC-12 initially agreed. However, a search of Fairbank’s cell found no hidden phones or communication devices. During questioning, Fairbank seemed genuinely confused, though his Alzheimer’s and memory loss likely contributed to his inability to explain things. He repeatedly stated he had no idea what they were talking about.

Detective Constable Chloe Bishop (Shalom Brune-Franklin) saved the day! Viewers of Line of Duty have been questioning the motives of the intelligent new member of AC-12 since she joined this season, but it turns out those suspicions were completely unfounded.

Chloe’s research cracked the case. She thoroughly reviewed old and new files related to Lawrence Christopher and Operation Lighthouse, and discovered handwritten notes from Buckells. He consistently misspelled “definitely” as “definately” – a mistake also made by the person communicating with Jo and the criminal group. This misspelling wasn’t a distraction; it was the crucial piece of evidence they needed to identify him.

AC-12 gathered more evidence against Buckells and brought him in for questioning. Steve, Ted, and Kate (likely borrowed from the Lighthouse team) led the interrogation, while Patricia Carmichael chose to watch from the doorway, maintaining a safe distance.

The proof was clear and convincing. During questioning, despite Buckells’ repeated refusals to answer, the AC-12 team presented a laptop with fingerprints found hidden in his prison cell, IP addresses linking him to Thurwell’s location in Spain, and evidence from the deliberate misspelling of “definitely.”

Investigators discovered messages indicating he was behind the plot to kidnap and kill both Jo and DI Kate Fleming. They also found he owned properties worth £3 million – much more than his income would allow. A hard drive recovered from one of these properties contained his fingerprints and DNA, along with proof he authorized the 2019 raid on the Eastfield Depot.

Seeing the proof, Buckells knew he couldn’t avoid answering questions any longer. However, he had a strategy. He explained that DCS Carmichael was supposed to be handling the case, but her absence made him suspect she didn’t want to be involved in uncovering widespread corruption – something officials claim doesn’t even exist. He pointed out that the mysterious ‘H’, or whoever was responsible, wasn’t officially recognized either. Buckells believed everyone would prefer the matter to be dropped, and he offered to provide information in exchange for immunity and witness protection.

Buckells started telling me what really happened, and it turns out the idea about four ‘H’s controlling everything was wrong. Apparently, the story about what Dot said before she died wasn’t quite accurate – it seems like the whole theory was a little shaky.

Tommy Hunter was the original leader, and after he died, the criminal organization fractured into several smaller groups. At that time, Buckells was a low-ranking officer simply relaying instructions. Fairbank and Thurwell were the leaders before Hunter, then Derek Hilton and Dot Cottan took over, and eventually Buckells assumed control. He didn’t mention Gill Biggeloe, whom AC-12 had previously considered a potential ‘H’.

Buckells’ attempt to get witness protection or immunity was derailed when AC-12 questioned whether he and Chief Constable Osborne had conspired to murder Gail Vella. Unlike other situations where they simply went along with criminal plans, AC-12 suspected Buckells and Osborne had actually ordered the killing. Buckells learned from Lee Banks that Gail was investigating the Lawrence Christopher case and wanted to stop her from uncovering the truth.

Steve leaned in, letting me know pretty clearly that if I didn’t play ball with the investigation, witness protection was off the table. Then Kate jumped in, making it even simpler: admit to being part of a murder conspiracy, and forget about any kind of deal to avoid prosecution. Basically, they were saying I was stuck between a rock and a hard place.

Ted Hastings famously declared, “No one makes mugs of AC-12,” and Buckells was returned to prison – where he’s still held. However, it was revealed that the police have requested to keep certain evidence secret in the case against him, claiming it’s in the public interest. If approved, this would mean the court wouldn’t hear any evidence of wider corruption within the police force, potentially allowing Buckells to get away with his actions.

Got it? OK, now we’ve got that sorted, let’s talk about what else happened in the episode:

The OCG strongbox under the floor

Lewis, a man with a beard, and another member of the organized crime group went to the gun workshop after a tip from Ryan, supposedly to break up the floor and steal a strongbox belonging to the group. However, the police arrived before they could, and both men were killed. Later, Kate had the idea to use radar to scan below the surface, and it worked – they found a box containing items belonging to the organized crime group.

It’s been established that the criminal organization’s leaders keep evidence to control others, forcing both corrupt police officers and gang members to cooperate. Detective Chief Inspector Chris Lomax found blackmail material in a storage box – specifically, the knife Ryan Pilkington used to kill PC Maneet Bindra, and the gun and gloves Carl Banks used in the murder of Gail Vella. However, not everything was as it seemed. Steve already knew the knife with Jackie Laverty’s blood on it had been planted in Tony Gates’s hand to frame him.

The prison officers kidnapped Jo to kill her

Leland and Merchant, the villains from Line of Duty, are corrupt prison officers working for a criminal gang. In this episode, they received orders to kill prisoner Jo Davidson, who was considered a high risk. Because Davidson was in a secure unit with constant surveillance, they couldn’t reach her directly. Instead, they devised a daring plan – likely with assistance from others – to move her to a transport van, allowing the criminal gang to stage a kidnapping.

A fake “production order” was used to bring Jo Davidson in for questioning at Hillside Lane Police Station. It appeared genuine in the system, complete with forged signatures from DS Chris Lomax and DI Kate Fleming. Leland, Merchant, and an associate then put Jo in a van with the intention of staging an ambush. Their plan was for masked individuals to intercept the police transport on its way to the prison, pretending to have weapons and control of the prison officers. This would allow them to kidnap and kill Jo, effectively eliminating her as a problem.

However, AC-12’s Amanda Yao managed to intercept a coded message from “H” to his criminal associates – they’d seized communication devices at Thurwell’s Spanish home, which helped. This meant Jo was in serious danger! AC-12 quickly mobilized, piecing together the information and tracking the van to reach Jo before the criminals could.

AC-12 then took a significant risk. Without the audience seeing it, Steve and Kate intercepted the van, taking Leland, the prison guard, out of the back and replacing her with Kate, who was now armed and ready for a fight. Steve took over driving, leaving Merchant with no choice but to accept the new arrangement. So, when the masked men tried to ambush the van as planned, they were caught off guard by Steve and Kate, quickly followed by a large group of armed police officers who were already positioned nearby.

As a huge fan of the show, I was on the edge of my seat when they pulled off that bold move! It allowed AC-12 to finally arrest more of the masked officers, but more importantly, it really drove home to Jo that ‘H’ was genuinely trying to kill her, and that they needed to unmask him – fast. It was a brilliant way to escalate the tension!

Steve finally went to Occupational Health

Steve pulled off the daring van ambush using only a taser and a gun he slyly took from one of the masked men. He’d been forced to give up his official firearms license after Occupational Health made him attend an appointment, threatening to suspend him if he didn’t.

During a medical check-up, Steve (played by Steve Oram) learned his urine showed dangerously high levels of painkillers. The counsellor mentioned Steve’s severe attack in season four and questioned his explanation that the medication was only for a few minor sports injuries. The counsellor advised Steve to take a break from work and warned him he’d need to voluntarily give up his firearms licence, or it could be taken away from him. He also gently explored the emotional distress Steve might be experiencing after witnessing the deaths of so many colleagues.

That all makes sense. It didn’t seem like Steve was being punished, but rather that everyone was focused on his well-being and safety. Both Steve and Kate are now receiving treatment and therapy, as they’ve both been through a lot recently.

Hastings came clean on John Corbett

Man, the tension was killing me! Just as Ted was about to go rip into Carmichael about Buckells being ‘H’, Steve and Kate jumped in and decided it was time to lay everything out for him. He definitely didn’t give it up easily – there was a lot of dodging and weaving – but once he finally confessed, it was such a relief! That whole scene with Line of Duty’s core three – Ted, Steve, and Kate – finally had some breathing room.

They started by telling him Steve had been talking to Steph. Ted then tried to make it seem like Steve was the problem, claiming Steph had told him about Steve’s struggles with painkillers and that Ted had offered Steve a chance to get help. He called this being a loyal friend.

They then revealed to him that Steph had a stash of £50 notes hidden in her attic – a gift from Ted. Ted admitted he had kept half of the bribe money, but justified it by saying it was used for a worthwhile purpose. He then asked if that concluded the discussion.

After giving Ted an opportunity to confess on his own, which he didn’t take, Steve and Kate revealed the truth: Ted had told Lee Banks about a police informant within the criminal organization, ultimately leading to the death of undercover officer John Corbett. Faced with this evidence, Ted could no longer deny his involvement.

He insisted he hadn’t revealed John Corbett was an undercover officer. He explained that he only told Lee Banks there was an informant within the criminal group, without giving any further details. He’d hoped that Corbett, upon hearing this, would turn himself in to the police – that was his plan to bring him in. He swore he was telling the truth.

When asked if he realized Corbett might be hurt, he admitted that was the hardest part. Corbett had been responsible for the deaths of four police officers, including one close to him, and had brutally attacked his wife, leading him to believe Corbett deserved whatever happened. However, he later discovered Corbett was the son of someone he had cared for deeply in the past – a revelation he deeply regrets. He sees giving money to a young woman as a small attempt to make amends for his actions. He worries about Steph finding out and how she would react, and questions who would ultimately judge what he did – her, the law, his coworkers, or a higher power?

Steve and Kate weren’t sure how to handle what they’d learned from their off-the-record interview. However, Ted ultimately took matters into his own hands and admitted to something—though his confession wasn’t exactly straightforward.

I couldn’t believe it when Ted told Carmichael he was fighting his forced retirement and walked out of AC-12. But then he came right back, and dropped a bombshell – he admitted he was the one who gave Lee Banks the information that ultimately led to Corbett being killed. Carmichael looked pretty surprised, to say the least!

The confession felt weak and unlikely to go anywhere. Carmichael doesn’t seem genuinely interested in investigating police corruption, and she won’t pursue this if it doesn’t help her career. She didn’t take any notes or record the conversation, as far as we know. It might ease Ted’s mind and reassure Steve and Kate a little, but it was a very hesitant and unconvincing admission. Importantly, he still hasn’t revealed the £50,000 he secretly gave to Steph Corbett.

Jo Davidson in witness protection

Jo Davidson managed to enter witness protection by cooperating with AC-12 and naming Fairbank, even though he wasn’t the real mastermind. The final scenes showed us just how comfortable her new life was – a cozy cottage, a loving girlfriend, and even a golden retriever! She clearly landed on her feet, especially when you consider what happened to Gill Biggeloe. So far, her fears of being targeted while in witness protection haven’t come true, and she seems safe and happy.

There’s good news for Terry Boyle (Tommy Jessop): he’s moved into a comfortable group home with other people who have Down’s Syndrome. He received a warm welcome, and this move should protect him from being taken advantage of. An investigation is also underway to understand why the systems meant to safeguard him previously failed.

And Farida is out of jail and back on active duty at Hillside Lane. Good for her!

Future of AC-12 still in doubt when season 6 wrapped up

Even with Buckells in custody and Darren Hunter being investigated for Lawrence Christopher’s murder, it’s not a satisfying conclusion to season six for AC-12.

Despite being retired, Ted Hastings may challenge that decision. The effort to restructure units AC-3, AC-9, and AC-12 is ongoing. People close to the Chief Constable have been given key positions in the anti-corruption department. Steve Arnott needs to address both his addiction and his physical health issues. Kate Fleming hopes to return to AC-12, but doing so could jeopardize her career. And corruption within the police force continues to be a major problem. Throughout the series, the anti-corruption team has been removing corrupt officers, but they haven’t been able to eliminate the widespread corruption.

Carmichael is gaining power. When Kate informed her about MIT reopening the investigation into the Lawrence Christopher case, Carmichael simply wished them “good luck” and then refused Steve’s request to also investigate the police officers involved in the mishandled case overseen by SIO Thurwell, stating that looking into past corruption wasn’t a priority. She also told Ted that, even with all the evidence, she still believes Ian Buckells acted alone, and isn’t ready to consider it a case of widespread, institutional corruption.

Despite concerns raised about his conduct, Chief Constable Philip Osborne is still leading Central Police. He recently made a strong public statement, similar to something a villain might say, in which he promised a full investigation of any mistakes made in the initial inquiry and pledged to learn from them. He stated that he has always acted against wrongdoing, but insisted that any issues were caused by a few dishonest individuals, not systemic corruption. He also argued that the public wants the police to focus on their work, not be constantly scrutinized for minor errors.

As a huge fan, it really hit me when they started taking all the photos down from the AC-12 board and boxing them up – it felt like the end of an era. Then, Jed Mercurio delivered that final line, and it was chilling. Basically, he was saying that right now, AC-12 has less power to fight corruption than ever before. It left me with a really uneasy feeling, and a lot to think about!

What we know going into season 7

AC-12 has been replaced by the Police Standards Inspectorate, which continues the important work of fighting corruption within the police force – a problem that unfortunately still exists.

The latest episodes center around the team’s most challenging case so far: Detective Inspector Dominic Gough, known for successfully dismantling organized crime groups, is now facing accusations of sexual assault. Steve, Kate, and Hastings are leading the investigation.

But is Gough’s case merely a smokescreen for a “bigger threat still hiding in the shadows?”

Still thinking about that finale? I’ve been digging around and found some great discussions about lingering questions from Line of Duty, and also a fun rundown of all the misleading clues they threw at us throughout the whole series. Definitely worth checking out if you’re as obsessed as I am!

Line of Duty seasons 1-6 are available to stream on BBC iPlayer.

2025-11-19 14:46