The BEST Episodes of Line of Duty

Every episode ever - ranked by fan votes!

Last Updated: Jun 10, 2021

Network: BBC One

A drama about the investigations of AC-12, a controversial police anticorruption unit.

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Episode 6

#1 - Episode 6

Season 3 - Episode 6 - Aired Apr 28, 2016

DS Steve Arnott is arrested on suspicion of murder but continues to protest his innocence. Does DC Kate Fleming's undercover operation hold the key to Steve's guilt and the identity of the Caddy?

star 8.63
1,626 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 5

#2 - Episode 5

Season 3 - Episode 5 - Aired Apr 21, 2016

AC-12's loyalties are divided when DS Steve Arnott comes under scrutiny from his colleagues. With his career in jeopardy, Arnott turns to an unlikely source for help.

star 8.34
1,580 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 6

#3 - Episode 6

Season 4 - Episode 6 - Aired Apr 30, 2017

While Nick Huntley faces lengthy questioning, AC-12 remain convinced of Roz's involvement.

star 8.28
1,388 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 4

#4 - Episode 4

Season 6 - Episode 4 - Aired Apr 11, 2021

DCI Jo Davidson faces increasing pressure from all sides as AC-12 make major breakthroughs in the investigation, but an attempt to interview a key witness goes horribly wrong.

star 8.28
430 votes
Directors: Gareth Bryn
Writers: Jed Mercurio
Episode 5

#5 - Episode 5

Season 6 - Episode 5 - Aired Apr 18, 2021

AC-12 link Gail Vella’s murder with a historic case of police corruption, and Kate hatches a plan to tell once and for all if Jo is bent. They are closer than ever to cracking the case, but when Hastings’ authority is undermined it leaves his team in a potentially dangerous situation.

star 8.21
424 votes
Directors: Jennie Darnell
Writers: Jed Mercurio
Episode 6

#6 - Episode 6

Season 5 - Episode 6 - Aired May 5, 2019

In a nail-biting 90-minute finale, Hastings's secrets are laid bare. Will 'H' be revealed at last?

star 8.21
686 votes
Episode 4

#7 - Episode 4

Season 5 - Episode 4 - Aired Apr 21, 2019

Tensions rise in the OCG following the events at Eastfield. With troubling questions hanging over the identity of ‘H’, suspicions mount at AC-12.

star 8.12
723 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 3

#8 - Episode 3

Season 4 - Episode 3 - Aired Apr 9, 2017

As AC-12 wrestle with the new forensic evidence casting doubt over Tim Ifield, Kate is approached by another woman claiming to have been assaulted by Michael Farmer. While Steve fumes over this contradictory testimony, Kate uses her newfound respect to inveigle herself with the Trapdoor team. Meanwhile, Steve challenges Roz's husband Nick to vouch for his wife's whereabouts on the night Tim Ifield went missing. With Nick proving evasive, Steve senses a whole new angle on the investigation.

star 8.12
1,418 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 5

#9 - Episode 5

Season 2 - Episode 5 - Aired Mar 12, 2014

Lindsay fights for her life as troubling details emerge of a vicious conspiracy involving corrupt police officers. With growing evidence of links between DCC Dryden and the ambush, Hastings is under pressure to arrest his senior officer.

star 8.08
1,351 votes
Directors: Daniel Nettheim
Writers: Jed Mercurio
Episode 6

#10 - Episode 6

Season 6 - Episode 6 - Aired Apr 25, 2021

As AC-12 struggle to deal with the repercussions of tragic events, Hastings makes one final bid to uncover institutionalised corruption before his time runs out.

star 8.07
411 votes
Directors: Jennie Darnell
Writers: Jed Mercurio
Episode 5

#11 - Episode 5

Season 4 - Episode 5 - Aired Apr 23, 2017

DCI Roz Huntley struggles to allay her husband's suspicions. AC-12 find a new angle to pursue their case against her.

star 8.06
1,360 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 5

#12 - Episode 5

Season 5 - Episode 5 - Aired Apr 28, 2019

As the hunt for 'H' intensifies, Steve and Kate wonder if Hastings is guarding a dark secret.

star 8.04
698 votes
Episode 4

#13 - Episode 4

Season 4 - Episode 4 - Aired Apr 16, 2017

Roz's husband Nick is brought in for questioning by AC-12. But while Nick denies any involvement in Steve's attack, his suspicions about Roz mount. Meanwhile, AC-12 discover new anomalies in the forensic evidence and issue DCI Roz Huntley with a second Reg 15 notice. AC-12's case appears watertight until Roz starts dismantling their evidence with inside information of her own.

star 8.02
1,416 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 2

#14 - Episode 2

Season 5 - Episode 2 - Aired Apr 7, 2019

Kate and Steve attempt to track down a lead. A fresh police leak enables another audacious raid. Steve’s attempts to gather information put him in a dangerous situation.

star 8.01
750 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 4

#15 - Episode 4

Season 2 - Episode 4 - Aired Mar 5, 2014

Following the violent attack she suffered in prison, Lindsay is granted special dispensation to visit her dying mother. Meanwhile, deputy chief constable Dryden shrugs off allegations about his relationship with Lindsay and possible links to the ambush.

star 8.00
1,335 votes
Directors: Daniel Nettheim
Writers: Jed Mercurio
Episode 5

#16 - Episode 5

Season 1 - Episode 5 - Aired Jul 24, 2012

With Gates on the run, the anti-corruption team come under pressure to close the case once and for all. Arnott is forced to make some tough decisions about where his loyalties lie. Fleming and Hastings go all out to catch Gates, leading to a shattering conclusion.

star 7.98
1,605 votes
Writers: Jed Mercurio
Episode 6

#17 - Episode 6

Season 2 - Episode 6 - Aired Mar 19, 2014

AC12's investigation finally exposes a vicious criminal gang run from within the police. But while Steve now appears convinced of Lindsay's innocence, Kate remains determined to prove she had a role in the ambush.

star 7.97
1,281 votes
Directors: Daniel Nettheim
Writers: Jed Mercurio
Episode 3

#18 - Episode 3

Season 5 - Episode 3 - Aired Apr 14, 2019

Corbett’s most daring plan yet requires McQueen to exploit links with corrupt police officers. AC-12 make a shocking discovery.

star 7.97
762 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 4

#19 - Episode 4

Season 3 - Episode 4 - Aired Apr 14, 2016

Fresh testimony launches AC-12 back on the trail of the Caddy, a corrupt officer with links to organised crime. But new disturbing evidence suggests the Caddy may reside within AC-12.

star 7.96
1,525 votes
Directors: John Strickland
Writers: Jed Mercurio
Episode 3

#20 - Episode 3

Season 6 - Episode 3 - Aired Apr 4, 2021

On the strength of evidence from a new witness, DCI Jo Davidson brings Terry Boyle back in for questioning about Gail Vella's murder. Kate is torn between loyalty to Jo and wanting to assist AC-12's investigation, and tensions increase when Kate encounters a face from the past with links to organised crime.

star 7.95
418 votes
Directors: Gareth Bryn
Writers: Jed Mercurio
Episode 1

#21 - Episode 1

Season 2 - Episode 1 - Aired Feb 12, 2014

A brutal ambush on a police convoy leaves three officers dead and a protected witness fighting for his life. AC-12 turn their spotlight on Lindsay Denton, the officer who led the convoy but escaped unscathed.

star 7.95
1,524 votes
Writers: Jed Mercurio
Episode 1

#22 - Episode 1

Season 4 - Episode 1 - Aired Mar 26, 2017

DCI Roz Huntley is under intense pressure from her superiors to apprehend a serial murderer after months of fruitless investigation. When another young woman is abducted, Roz is on the scene to track down and charge a 24-year-old man. But doubts around the young man's guilt lead the chief forensic investigator to ask AC-12 to investigate. Is Roz ignoring forensic evidence that might prove the young man's innocence? AC-12's Supt Hastings places DS Kate Fleming undercover inside Roz's team to dig deeper into the case. With DS Steve Arnott piling on pressure from the outside, Roz is forced to act decisively. A mother of two and wife to Nick, Roz will do anything to stop her life from unravelling.

star 7.95
1,594 votes
Directors: Jed Mercurio
Writers: Jed Mercurio
Episode 2

#23 - Episode 2

Season 6 - Episode 2 - Aired Mar 28, 2021

Having opened an official inquiry into DCI Jo Davidson and Operation Lighthouse, AC-12 begin to suspect a cover up. Steve and Chloe dig into Gail Vella’s controversial reporting for clues to her murder, and find links to previous AC-12 cases. Their investigation takes a shocking turn when they begin to scrutinise Jo's personal life.

star 7.95
426 votes
Directors: Daniel Nettheim
Writers: Jed Mercurio
Episode 1

#24 - Episode 1

Season 3 - Episode 1 - Aired Mar 24, 2016

Police anti-corruption unit AC12 return for another investigation. Sergeant Danny Waldron and his armed response team shoot dead a hardened criminal, but cracks soon appear in their story. Are they hiding a cold-blooded murder?

star 7.94
1,617 votes
Directors: Michael Keillor
Writers: Jed Mercurio
Episode 1

#25 - Episode 1

Season 5 - Episode 1 - Aired Mar 31, 2019

Following the deadly hijack of a police convoy, AC-12 target a ruthless organised crime group known to have links with corrupt officers.

star 7.93
780 votes
Directors: John Strickland
Writers: Jed Mercurio