'Line of Duty' Series 3 has seen the regulars of AC-12 - Arnott, Fleming and their boss Hastings, not to mention that helpful colleague 'Dot' Cottan - joined by some faces new and old.
Each series has been critically acclaimed, with Lennie James' initial antagonist making way for Keeley Hawes, and then Daniel Mays. Jed Mercurio's scripts have famously stretched the actors, with the interview scenes alone covering as many as 27 pages, and taking whole days to shoot.
Just as well it's a pedigree cast involved, but where have we seen them before?
Line Of Duty Cast: Where Have We Seen Them?
Daniel Mays as Sergeant Danny Waldron(01 of09)
Until he met a grisly, untimely fate in Episode 2 of Series 3, it looked as though Daniel Mays was going to prove a worthy successor to AC-12's previous antagonists. Daniel previously played Ronnie Biggs opposite Sheridan Smith in 'Mrs Biggs', as well as appearing in 'Red Riding', 'Ashes To Ashes', 'Outcasts' and 'Doctor Who'.
Will Mellor as PC Rod Kennedy(02 of09)
Another familiar face, another grisly fate in 'Line of Duty'. Will's been a familiar face on British TV since his breakthrough role in 'Hollyoaks', followed by 'Casualty'. 'Two Pints of Lager and a Packet of Crisps' brought him to a different audience. He's since appeared in 'Waterloo Road', 'White Van Man', 'Broadchurch' and 'Death in Paradise'.
Keeley Hawes as Lindsay Denton(03 of09)
Keeley was such a success in Series 2 of 'Line of Duty', she's back for more in the third. Prior to this career-confounding role, Keeley's work has tended to be more glamorous. Period dramas 'Our Mutual Friend' and 'Wives and Daughters' made way for her lead roles in 'Tipping the Velvet' and 'Spooks'. She is best known for these as well as 'Ashes to Ashes' and the rebooted 'Upstairs Downstairs'. She also stars in ITV's 'The Durrells'.
Martin Compston as Detective Sergeant Steve Arnott(04 of09)
He hides it well in 'Line of Duty', but Martin is a native Scott with a beautiful burr of an accent. Discovered by director Ken Loach in his native Glasgow, Martin was a young face in Loach's film 'Sweet Sixteen', before making 20 episodes of 'Monarch of the Glen'. He's done his time on shows including 'Casualty' and 'Silent Witness' but mostly worked north of the border until the first series of 'Line of Duty' brought him a much bigger profile. He's also turned up in 'Death in Paradise'.
Vicky McClure as DC Kate Fleming(05 of09)
Along with 'Line of Duty', Vicky's most consistent role has been in Shane Meadows' ''This is England' series, which saw her improvise constantly in her role of Frances Lorraine Jenkins. She's also been in 'Broadchurch' and will appear in forthcoming TV drama 'The Secret Agent'.
Craig Parkinson as DI Matthew 'Dot' Cottan(06 of09)
Before his deceptively laid-back role in 'Line of Duty', Craig was most familiar in 'Whitechapel' as both Jimmy and Johnny Kray. He also appeared in 'Misfits', 'Great Night Out', 'The Mill' and 'Prey'.
Polly Walker as Jill Bigelow(07 of09)
Polly has been on the big and small screen for nearly 30 years. Her film roles have included 'Enchanted April', 'Patriot Games' and 'Clash of the Titans', while TV shows have included 'The Mayor of Casterbridge', 'State of Play', 'Rome' for which she was Golden Globe-nominated, 'Mr Selfridge' and 'The Syndicate'.
Adrian Dunbar as Detective Superintendent Ted Hastings(08 of09)
A theatrical force in his native Northern Ireland, Adrian has appeared in films from ‘My Left Foot’ to the BAFTA-nominated ‘Hear My Song’, which he co-wrote. On TV, he’s put in consistently well-received performances, from the very first episode of ‘Cracker’, to the last episode of ‘A Touch of Frost’. In ‘Ashes to Ashes’, he was the mysterious Martin Summers, and in 2014 he played the title character in BBC comedy drama ‘Walter’.
Neil Morrissey as DC Nigel Morton(09 of09)
Like Keeley Hawes, Neil has defied all expectation with his role in ‘Line of Duty’. Prior to this, he was best known for his role of appealing but hopeless bachelor Tony in ‘Men Behaving Badly’. He also played Rocky in ‘Boon’ and was the voice of Bob, Lofy and Farmer Pickles in ‘Bob The Builder’. More recently he played deputy head Eddie Lawson in ‘Waterloo Road’, and guest-starred throughout the second series of ‘Grantchester’. And yes, he too has been in 'Death in Paradise'.
'Line of Duty' continues on BBC Two on Thursday at 9pm.