Mother of God, what a finale. Not only did the last episode of Line of Duty’s fifth series feature a phenomenally tense interview scene, but the action-packed instalment also finally unmasked a corrupt senior member of police staff, Gill Biggeloe (Polly Walker).


As many suspected, the Police and Crime Commissioner’s legal advisor was secretly linked with the OCG and was a key player in the plot to frame Ted Hastings (Adrian Dunbar).

As a recording obtained by DI Kate Fleming (Vicky McClure) and DS Steve Arnott (Martin Compston) revealed, it was Biggeloe who was largely responsible for John Corbett’s (Stephen Graham) vendetta against the AC-12 chief.

The lawyer wasn’t only instrumental in recommending Corbett for undercover operation Pear Tree, but also convinced him that Hastings was the reason his mother, Anne-Marie McGillis, was murdered by paramilitary forces.

Yet despite these major breakthroughs, the episode didn’t clear up all the show's major mysteries. Here are the big questions still unanswered after series five.

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What did Dot Cottan’s dying testimony actually mean?

After all the main twists of the show’s central interview, there was one major surprise for viewers – a new piece of information that completely upended most theories about the identity of ‘H’.

In a twist similar to the identity of ‘Balaclava Man’ in series four, it turns out that ‘H’ is not just one person but a group.

Line of Duty, BBC Pictures

The major revelation came after a fresh look at the dying declaration of Matthew 'Dot' Cottan (Craig Parkinson), the bent copper who jumped in the way of bullets aimed at DI Kate Fleming in the series three finale. Before dying from his wounds, Cottan delivered a dying declaration, which was recorded on an officer’s helmet camera.

Blinking when the letter ‘H’ was read out to him by Fleming, it was previously thought that Cottan – who was unable to speak due to his severe injuries – had signalled there was one high-ranking officer in the police with connections to the OCG whose name began with that letter.

However, it looks Cottan's message was misinterpreted.

Dot's dying declaration

At the end of the series five finale, Arnott spotted that during his final moments, Cottan wasn’t just using his eyes to send officers a signal. “Dot was trying to tell us something before he lost consciousness. He couldn’t speak due to the gunshot wound to his chest, but he could move his hand,” the DS explained to Hastings.

Pointing to Cottan’s fingers in the video, Fleming deduced that he was repeating a pattern of telling taps on his left hand: “Tap tap tap tap. Tap tap tap tap. It’s Morse code. Dot dot dot dot.”

“The letter H in Morse code is four dots,” added Arnott. “‘H’ is not an initial, it’s a clue. Four dots. Four caddies. Four police staff in league with organised crime.”

As Fleming said, we now know four of them: Assistant Chief Constable Derek Hilton, legal counsel Gill Biggeloe and Cottan himself.

In other words, the dying declaration wasn’t trying to expose one individual whose name starts with ‘H’. Cottan was trying to say there were four key OCG members embedded in the police service – their names don’t necessarily start with that letter.

It’s a twist that leads on to another key question. No, not how on earth Arnott was able to spot Cottan’s hands tapping from a single frame of footage. Something much more important…

Who is the final ‘H’?

It's the great big mystery due to hang over the next series – the final corrupt policeman working in league with the OCG.

There are some obvious contenders. Ted Hastings may have been exonerated by Steve and Kate in the series five finale, but there are still a number of black marks against his name (you can read all about them here). Then there's the possibility that another senior ranking officer we're already familiar with – like DCS Patricia Carmichael or DCC Andrea Wise – might be the bent copper we're all hunting for.

Line of Duty S5 - Episode 6

OR there's a chance we're yet to meet the final piece of the puzzle. We'll certainly have our eye on any major guest stars cast in series six...

How did Lee Banks know there was a rat in the OCG?

By the end of series five we’re still not sure how imprisoned OCG member Lee Banks knew there was a member of the criminal gang who was leaking information to the police. And this is a crucial point: it was Banks’ tip-off to Lisa McQueen that alerted her to an informant in her unit, which she soon discovered to be John Corbett.

So, who passed over this intel that led to Corbett’s killing? Despite it being proven (for now) that Hastings isn’t a bent copper, there are still plenty of reasons to suggest the AC-12 chief was behind the leak.

Firstly, his devastated reaction when Detective Chief Superintendent Patricia Carmichael (Anna Maxwell Martin) revealed Corbett’s true identity could be very telling.

Lee Banks in prison
OCG member Lee Banks

Was Ted in tears as he had just learned that the son of Anne-Marie – a woman that he was close to during his time in the Royal Ulster Constabulary (RUC) – was dead? Or was Hastings especially distressed by the knowledge he was responsible for the murder?

Carmichael thought the latter. And not only did she suspect Hastings told Banks that there was a rat in the OCG, but that – perhaps as revenge for assaulting his wife – he named Corbett as an undercover officer.

As we’ve covered previously, there is good evidence for this, with Hastings’ explanation for visiting Lee Banks – to gain more intel about the OCG – pretty unconvincing.

Line of Duty - Lisa McQueen and John Corbett
Lisa McQueen and John Corbett

However, there’s always the chance that Lee Banks never told Lisa McQueen there was a leak in her unit. After all, we’ve only got McQueen’s word Lee Banks tipped her off. And, as we know, she’s unreliable, having no problem lying to the police.

In fact, immediately after claiming the intel about the leak came from Banks, she told AC-12 that it was Miroslav (Tomi May) who cut Corbett’s throat, not the actual killer Ryan Pilkington (Gregory Piper).

It could also be very significant that earlier in the series we saw McQueen figure out there was a rat in the unit without the help of Lee Banks. Remember, after the raid at Kingsgate Printing Services, she deduced the location of the OCG headquarters must have been leaked by one of their own.

Following this, it was clear she suspected Corbett. Later that same episode, she staged a fake meeting with ‘H’ to test whether Corbett would leak this information to the police. And according to her (albeit unreliable) AC-12 interview in the series finale, McQueen had her suspicions confirmed when an OCG informant spotted armed police at the staged shopping centre rendezvous.

This all means there’s a chance Hastings passed absolutely no information onto the OCG after all, with McQueen figuring out Corbett’s identity independently. But if it wasn't to leak Corbett's identity, what was Ted doing? We've never seen him look as cold and calculating as he did in that visitor room.

Is Ted off the hook?

Ted Hastings in Line of Duty, BBC Pictures

In a word, no. Kate and Steve may have dug out evidence to get him out of a sticky situation, but just because he's no longer under formal investigation, doesn't mean Ted is squeaky clean. After all, there were a number of clues that were left unresolved by the series finale.

Did Ted really have time to closely study the linguistic habits of the corrupt officer communicating via instant messenger in order to replicate their spelling of "definitely" with an "a"? As excuses go, that one was pretty flimsy – as was his line that he'd ditched his laptop to avoid being caught watching pornography (more on that below).

Series five built up a solid case against Ted Hastings. And we're yet to be entirely convinced of his innocence.

Did Ted give £50k to Steph Corbett?

Alongside learning Operation Pear Tree had been closed and Mark Moffat was convicted for bribery, the episode’s closing montage hinted at a touching moment between Ted Hastings and John Corbett’s wife, Steph.

As the widow placed flowers on John’s grave, we saw Hastings walk through the graveyard with a mysterious envelope in hand. What was inside? The obvious answer: a cash sum of up to £50,000, half of the money Moffat tried to bribe Ted with.

Judging by the text on screen at the time, this seems very likely. As Hasting strolled up to Steph, the following words appeared: “No evidence has been uncovered to account for a missing £50,000.”


Did Hastings hand over all the cash to Steph? Is this further proof that he feels responsible for Corbett’s death? And, most importantly, will this bribery cash come back to incriminate Hastings next series?

Did Ted really use his laptop for pornography?

After weeks of asking, we finally have an excuse for why Hastings disposed of his laptop – but it’s not a very good one.

During Hastings’ lengthy interview with AC-3, Carmichael repeatedly probed him about his visit to a computer disposal centre, evident in several CCTV images.

After repeatedly avoiding the question, Hastings finally caved. “I was looking at pornography,” he reluctantly told Carmichael. “Nothing illegal. Nothing extreme. I did not want it to be found.”

Line of Duty S5 - Episode 6

Now, there’s no question Hastings is a proud man. He previously refused to alert police about his crippling debt, after all. But does his pride really explain why he wrapped up his computer in bubble wrap before delivering it by hand to the disposal centre?

Has nobody ever shown Ted how to delete his browsing history? Or how incognito mode works?

According to Carmichael, there is another explanation: Hastings used his laptop to talk with the OCG.

“We know from the recovered laptop in the nightclub that the OCG communicated with ‘H’ via online messaging,” she explained in the interview.

“While we’re still unable to determine H’s location, we know for certain that the hard drive of H’s computer would contain metadata proving it was used to communicate with the OCG – evidence he would take great pains to dispose of.”

Our best glimpse of Hastings’ laptop supports her theory. Earlier in the series, viewers could briefly see what looked like a suspicious messaging service on screen – not any kind of pornography.

Line of Duty laptop, BBC

Was Hastings actually messaging the OCG at the time? And did he lie to AC-3?

It’s possible. And although it’s clear now that Hastings is not the ‘H’, could he still be one of the four corrupt cops Cottan tried to expose in his dying declaration?

Did Ted Hastings have an affair with Anne-Marie McGillis?

Like the penultimate episode, the series five finale delved into Hastings’ back story in Northern Ireland's RUC – in particular, his relationship with Anne-Marie McGillis.

Mother to John Corbett, McGillis was a police informant who passed intel directly to Hastings during the Troubles in the late 1980s. And, as we learnt during the interview with AC-3, there were many question marks about the relationship between the two. Police reports at the time noted there were rumours that Hastings, a married man, was having an affair with the widowed McGillis.


“According to the file, you didn’t always meet in covert locations. You were seen entering and leaving her home,” said Carmichael, before probing Hastings further about their relationship. Hastings, however, dismissed this as “gossip”, claiming he was assisting Anne-Marie with “odd jobs” as she had “no man about the house”.

Ted’s liaisons with Anne-Marie provide a huge insight into his character. Even if Hastings didn’t conduct an affair, it’s clear the superintendent bears plenty of guilt for her death. He had met with her on 18th April 1989, the day she went missing, with Anne-Marie dropping off her son at a neighbour’s under false pretences. As Hastings admitted, he was the last reported person to see her alive.

Did he have anything to do with her disappearance? Or does Hastings, at least, know more than he’s letting on? At this point, we can only be certain we haven’t heard the full story of Anne-Marie McGillis just yet.

What will Ryan do – and who is Simon Banerjee?

Simon Bannerjee

Throwback time! Remember idealistic new Constable Simon Bannerjee (Neet Mohan) from Line of Duty series one, who was assigned to the patrol unit alongside his lazy and cynical colleague PC Karen Larkin? The one who seemed to be genuinely keen on making a difference in the world?

If you recall, Bannerjee was the cop who tried to help Ryan the BMX-riding burner phone delivery boy, handing him a card with his phone number: "That's just if there's stuff you want to talk about, or if you want someone to buy you a burger." Turns out he did, apparently, have an impact on young Ryan Pilkington (Gregory Piper) – but it may not have been positive.

Ryan grew up within the OCG and was involved in some of their most horrific crimes, ultimately slashing John Corbett's throat. But alongside all this, he was studying for his exams – and now he has aced his interview for police college.

"Where I grew up it was easy to fall in with the wrong crowd," he told the panel. "The person who made me see that there was another way to be a useful member of society was a police officer. PC Simon Bannerjee. He's the reason why I wanted to become a police officer too. To help people."

Was Ryan cynically using that encounter with do-gooding cop Bannerjee to create a plausible story for the interview panel? Or did he actually go for burgers with Bannerjee? Where is Bannerjee now, and is he crooked or straight? Perhaps he is part of this network of corrupt cops, and was building a link between him and Ryan and the OCG? There's so much to explore!

Hopefully we'll see more of Ryan Pilkington (and perhaps Simon Bannerjee) in series six as the police's newest recruit gets his feet under the table and starts working from the inside...


What could that dramatic Line of Duty finale mean for series six?