Stephen Graham stars as the guest lead in Line of Duty series five, putting in a menacing performance as the drama's latest villain.


Here's what you need to know...


Who is Line of Duty's John Corbett?

Stephen Graham as John Corbett, Line of Duty, BBC Pictures

John Corbett (played by Stephen Graham) was introduced to us at the start of series five as a "pivotal figure" in a "deadly organised crime group" that is "known to have links with corrupt police officers and suspected to be under direct command of the shadowy figure known only as 'H'."

Ahead of the first episode, Martin Compston teased: "He's the most dangerous guy we've come up against. By far." And, he added, "The other people we're usually chasing are cops. I mean – they're not out and out bad people. But he's just a criminal, he's a murderer."

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But it was all a massive misdirection!

After stumbling upon the top-secret Operation Peartree, DI Kate Fleming (Vicky McClure) and DS Steve Arnott (Compston) realised that the balaclava gang boss "John Clayton" was actually undercover officer DS John Corbett.

He had infiltrated the OCG on a mission to identify high-level corrupt officers with criminal connections – and now he had cut contact with his police handler and gone rogue. Was he truly turning to a life of crime? Why else would he lead a raid on a police convoy resulting in the death of multiple officers?

But when Corbett managed to make direct contact with Steve, he declared that he was still working undercover and was utterly determined to bring down the "top brass," only cutting his contact with Operation Peartree because he suspected he was being deliberately steered away from the truth by Det. Supt. Alison Powell (Susan Vidler).

Line of Duty episode 4

Corbett then passed on information to Steve about the gang and its activities, including details of his criminal colleague Lisa McQueen (Rochenda Sandall). This led to the arrest of Lee Banks, and the release of human trafficking victims from the gang's brothel, and the raid of the OCG's printshop headquarters. He also set up the Eastfield depot raid so that AC-12 could swoop in and arrest their police fixer. (Not that this plan worked out, exactly. Goodbye to DCS Lester Hargreaves and £50m of illicit goods.)

But despite working with Steve, Corbett was insistent that AC-12 boss Ted Hastings (Adrian Dunbar) was a bad guy – maybe even 'H'. He pleaded with Steve to open his eyes and to keep crucial secrets from Hastings, with mixed success. He also took matters into his own hands, visiting Mrs Hastings at home and apparently inflicting paramilitary punishment wounds as he tortured Ted's wife for information.

In episode four, things came to a dramatic conclusion for John Corbett. The undercover officer persuaded Steve not to arrest him or shoot him dead (despite direct orders from Hastings) and made his getaway, having apparently organised a meeting with 'H' at Palisade Shopping Centre. 'H' was a no-show and AC-12 were left with egg on their faces.

Next up for the OCG was a "livestock" deal; fresh victims of human trafficking would be handed over into the sex trade. This brought Corbett to his limit, especially when he heard the sounds of gang member Ryan (Gregory Piper) apparently raping one of the women in the next room. Having made a pact with Lisa, he blew his cover, grabbed Miroslav's gun from the poker table, and attempted to free the girls.

Line of Duty - Lisa McQueen and John Corbett

But Corbett had miscalculated. The whole incident was actually a ruse to get him to reveal himself as the "rat", and Lisa was in on the plan; she was never going to bail on the OCG and go straight. As Corbett realised he'd been tricked, Ryan jumped out and slashed his throat. RIP John Corbett.

What do we know about John Corbett's family in Ireland?

In episode four, we discovered that John was actually adopted at the age of 10 in 1989 by the Corbett family who were based in Liverpool. His adoptive mother’s maiden name was McGillis, and so she was probably a close relative of one of his birth relatives – because his surname at birth was also McGillis.

John McGillis was born in Belfast, and his father was Anthony Patrick McGillis, who died in 1984; his mother, Anne-Marie McGillis, died in 1989 – “hence Corbett’s move to Liverpool, and the adoption," as PC Tatleen explained.

Adding to the mystery was a phone call between John and his wife Steph, who reported a visit from Kate and Steve. “They was asking about Northern Ireland,” she told her husband. “They was even asking about family over there.”

“Well did they know anything? Anything about my mum, and anything?” John responded, while Steph asked: “What’s this all about? Do they know about Anne-Marie?”

It remains to be seen what Corbett's backstory will be, and if there is a connection to Belfast's very own Ted Hastings...

Where have I seen Stephen Graham before?

Stephen Graham in Boardwalk Empire (Sky)

An incredibly versatile actor, Graham now has more than 100 acting credits to his name. You may recognise him as Tommy from the film Snatch, or as Baby Face Nelson from Public Enemies, or as Al Capone in Boardwalk Empire, or as the slow-witted but scheming musical pirate called Scrum from the Pirates of the Caribbean films.

Graham has previously starred alongside Line of Duty's Vicky McClure in the movie This is England and its TV sequels This is England '86, '88 and '90, playing Andrew "Combo" Gascoigne.

Recent projects include Decline and Fall, Taboo, Save Me, and Little Boy Blue, in which he starred as Detective Superintendent Dave Kelly. He's also due to appear in Martin Scorsese's upcoming Netflix film The Irishman, and in the drama The Virtues.


Line of Duty continues on Sundays at 9pm on BBC1

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