50 free Line of Duty trivia questions with answers — entertainment quiz, new questions added Aug 2026.
Line of Duty was turned down by BBC One as too problematic for a mainstream audience, so Jed Mercurio took his anti-corruption drama to BBC Two in 2012 and built it into the most-watched British drama since records began. The format barely changed across six series: Superintendent Ted Hastings, DS Steve Arnott and DC Kate Fleming of AC-12 investigate one guest-star copper a year while a bigger conspiracy about a senior officer known only as "H" ticks away underneath. These 50 questions cover the whole run, from Tony Gates and TO-20 to the lockbox under the workshop floor. Expect Lindsay Denton and the Caddy, Roz Huntley's hand, the £50,000 in a hotel room, Operation Pear Tree and Operation Lighthouse, the Sport Relief sketch with Lee Mack, and the Belfast buildings that stand in for police headquarters. Easy questions stick to the three leads and the guest stars; the expert tier asks about cinematographers, composers, a balaclava shortage and the actor who quit series two after two days. Every answer is cited to a page we checked, with a short explanation so you pick something up even when you miss. Mother of God, fella — no pressure.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Who created and wrote every episode of Line of Duty?
Jed Mercurio
Mercurio also directed some episodes and called the show a "revisionist commentary on 21st-century policing".
Q 02What is the name of the anti-corruption unit at the heart of the show?
AC-12
AC-3 and AC-9 also exist in the show's world; in series 6 Osborne plans to merge all three and cut staff by 90%.
Q 03On which channel did Line of Duty first air in 2012?
BBC Two
It became BBC Two's highest-rated series in a decade before being promoted in 2017.
Q 04In which year did Line of Duty move from BBC Two to BBC One?
2017
The move followed a restructuring of the two channels and the show's huge BBC Two ratings.
Q 05Which character does Martin Compston play?
Steve Arnott
Compston is Scottish and adopts an English accent for the role; his three-piece suits made the waistcoat a running joke.
Q 06Vicky McClure plays which AC-12 officer?
Kate Fleming
Fleming starts as a DC and is promoted to DS at the end of series 3 and DI by series 5.
Q 07Who plays Superintendent Ted Hastings?
Adrian Dunbar
Dunbar was only supporting cast in series 1 and was promoted to the main credits from series 2.
Q 08Which corrupt DCI does Lennie James play in series 1?
Tony Gates
James was offered the part without an audition and flew back from Los Angeles to film it.
Q 09Keeley Hawes plays which officer investigated in series 2?
Lindsay Denton
Hawes said that when she first got the script, Mercurio had not yet decided whether her character was actually corrupt.
Q 10Which actor plays firearms officer Sergeant Danny Waldron in series 3?
Daniel Mays
Mays' character is killed early, with the script changed to bring Lindsay Denton back for the rest of the series.
Q 11Thandie Newton's series 4 character is which DCI?
Roseanne Huntley
Huntley ends up losing a hand to an MRSA infection traced back to forensic coordinator Tim Ifield.
Q 12Stephen Graham plays which undercover officer in series 5?
John Corbett
Corbett uses the alias John Clayton; Graham consulted a friend in Army intelligence who had done real undercover work.
Q 13Kelly Macdonald's series 6 character is which DCI?
Joanne Davidson
Davidson turns out to be the product of incest in the Hunter family and names Patrick Fairbank as her believed father.
Q 21Which AC-12 officer murders Denton in series 3?
Matthew "Dot" Cottan
Denton refused his bribe and emailed the abusers list to Hastings moments before she was shot.
Q 22Which senior officer accuses Hastings of being "H" in series 4?
Derek Hilton
Hilton is later found dead at the same spot as a murder linked to the Sands View boys' home.
Q 23What does Huntley lose to an MRSA infection in series 4?
A hand
The infection is traced to Tim Ifield, which helps prove she killed him.
How many years is Huntley sentenced to for Ifield's manslaughter and cover-up?
Q 14Which company produces Line of Duty for the BBC?
World Productions
World Productions also made Mercurio's Bodyguard; Simon Heath is its executive producer on the show.
Q 15Where was the first series of Line of Duty filmed?
Birmingham
The show's setting was later changed to a vague Midlands on the BBC's advice, and production moved to Belfast.
Q 16From series 2 onwards, in which city was Line of Duty filmed?
Belfast
Belfast Central Library's exterior serves as the police headquarters facade.
Q 17What peak audience did the series 6 finale reach in its final 15 minutes?
13.1 million
That made it the highest-rated UK drama since modern records began in 2002.
Q 18Who is finally unmasked as "the Fourth Man" in the series 6 finale?
Ian Buckells
He demands immunity and witness protection, is told he qualifies for neither, and is arrested.
Q 19What nickname does the crime group's man inside the police go by in series 1–3?
The Caddy
The name comes from his past carrying golf clubs for gang boss Tommy Hunter.
Q 20Which three-word text summons an armed escape during a series 3 AC-12 interview?
Urgent exit required
The scene was later shortlisted for Virgin TV's Must-See Moment award.
Ten
She admitted killing Ifield in self-defence and framing her husband Nick for it.
Q 25What is the codename of the series 5 undercover op that embedded Corbett in the OCG?
Operation Pear Tree
Gill Biggeloe helped select Corbett for the operation and steered him towards investigating Hastings.
Q 26The series 6 investigation into journalist Gail Vella's murder is known as what?
Operation Lighthouse
Vella had been developing a podcast about high-level police corruption when she was killed.
Q 27The murder of Gail Vella was based on the 2017 killing of which journalist?
Daphne Caruana Galizia
Caruana Galizia was the Maltese investigative journalist killed by a car bomb.
Q 28The show's opening scene was credited to the 2005 police shooting of which man?
Jean Charles de Menezes
De Menezes was wrongly believed to be connected to the London bombings.
Q 29What is the name of the boys' home at the centre of the series 3 abuse storyline?
Sands View
The BBC was uneasy about the storyline's references to Jimmy Savile but Mercurio persuaded them to keep it.
Q 30Davidson's team in series 6 is based at which police station?
Hillside Lane
The station set was built inside a former school so the crew could ventilate and distance during the pandemic.