You could say we’ve taken this too far. You could be right. You could also say that, for a Line of Duty fan attempting to solve the many mysteries of series six, it’s useful to have the hard facts at hand. How does the newly revealed “Fourth Man” suspect Marcus Thurwell fit into the timeline as we know it? What prompted him to take early retirement two years after he conspired to suppress the investigation into the racist murder of Lawrence Christopher? Was it a scent on the air telling him that two rookie officers – Fleming and Arnott – were on their way in the next couple of years, so he’d better high tail it to Spain before they reached their full powers? And then there are the real questions, such as: the day before AC-12 raided Hillside Lane Station in series six, it was Kate Fleming’s 35th birthday. Did she bring in doughnuts? Had Kate come in worse for wear from one too many glasses of white in Frederico’s with Jo? The people demand to know. Taken from police records glimpsed on screen and episode scripts, below are the key dates mentioned in Line of Duty, in chronological order, right from the start. We’ll update as series six continues. Use it to bolster your theories and beat your friends in arguments. Carry the fire, team.

Series One (Unknown 2012)

– Steve Arnott’s counter-terrorism op is botched and CI Osborne demands a cover-up. Steve refuses and is recruited by Ted Hastings at AC-12– DCI Tony Gates receives the Officer of the Year award and is investigated by AC-12 for manipulating his unit’s stats– OCG money launderer Jackie Laverty runs over her accountant. Her lover DCI Tony Gates helps to cover it up. She’s murdered by the OCG, who blackmail Gates to cover up a string of drug murders– DCI Gates gets a confession from OCG leader Tommy Hunter, delivers him to AC-12, then kills himself by stepping into traffic so his family receive a ‘line of duty’ pay-outNovember 2012 Deborah Devereux is arrested for assault against a neighbour, DI Buckells at Kingsgate Station has the charges dropped in exchange for sexual favours

Series Two (September – November 2013)

21st May 2013 DI Lindsay Denton terminates her pregnancy, at lover DCC Dryden’s behest16th August 2013 DCC Mike Dryden is photographed by the OCG engaging in a sex act with underage victim Carly Kirk, who goes missing that day. To fake an alibi, Dryden takes responsibility for his wife’s speeding ticket issued that evening5th September 2013 A police convoy transporting former OCG head-turned-witness Tommy Hunter is diverted by DI Lindsay Denton, then ambushed and three officers are killed14th September 2013 Tommy Hunter and DC Georgia Trotman are murdered in hospital by bent copper DS Jeremy ColeSeptember 2013 – DI Denton is charged with conspiracy to murder, remanded until the 18th of November 2013, released, then rearrested and sentenced to life, serving 585 days inside until her successful appeal.

Series Three (May to July 2015)

13th May 2015 Danny Waldron shoots dead his childhood abuser Ronan Murphy and instigates a police cover-up, later torturing Linus Murphy – another abuser – to death1st June 2015 Danny Waldron is fatally shot by PC Hari Bains, blackmailed by the OCG13th July 2015 Danny Waldron’s funeral takes place17th July 2015 Lindsay Denton is murdered by DI Matthew ‘Dot’ Cottan, who attempts to frame Steve Arnott for the crime18th July 2015 Dot sends an ‘Urgent exit required’ text to the OCG and is shot out of an AC-12 interview. Kate gives chase and Dot is killed saving her from an OCG bullet. She records his Dying Declaration giving clues to the identity of corrupt officers in league with the OCG2016 Patrick Fairbank is transferred to Queen’s Chase Open Prison due to declining health

Series Four (March to May 2017)

11th November 2016 The dismembered corpse of sex worker Baswinder Kaur is found25th January 2017 Leonie Collersdale, also a sex worker, goes missing9th March 2017 Hana Reznikova is abducted as part of the OCG’s attempt to frame Michael Farmer for the Operation Trapdoor murders17th March 2017 Roz Huntley hits her head at Tim Ifield’s flat and, thinking her dead, he makes plans to dispose of her corpse. She wakes up and in a struggle, accidentally kills Tim Ifield then attempts to cover it up by cutting off his fingers and disposing of his laptop and phone4th May 2017 Hastings fatally shoots a ‘Balaclava Man’ attempting to extract and/or kill solicitor Jimmy Lakewell from AC-12 headquarters5th May 2017 ACC Derek Hilton is found dead, supposedly a shotgun suicide but more likely murdered by the OCG. At a later date, Roz Huntley pleads guilty to the manslaughter of Tim Ifield and is sentenced to 10 years in HMP Brentiss Prison. Jimmy Lakewell pleads guilty to perverting the course of justice and is sentenced to HMP Blackthorn

Series Five (February to July 2019)

Late Dec 2018/Early Jan 2019 -Gill Biggeloe, working for the OCG, lies to John Corbett that Ted Hastings is the corrupt officer responsible for his mother’s death by the IRA. He records the conversation22nd Jan 2019 Operation Pear Tree officially begins, implanting John Corbett in the OCG15th Feb 2019 The OCG hijack a heroin shipment Eastfield Depot, murdering 3 corrupt police officers23rd Feb 2019 PC Maneet Bindra is murdered by the OCG. RIP27th Feb 2019 The OCG hijack a ballistics transport carrying firearms4th March 2019 Lisa McQueen meets with DCS Hargreaves, whom she’s been blackmailing over his visits to an OCG-run illegal brothel5th March 2019 The OCG raid the Eastfield Depot, John Corbett shoots Hargreaves dead10th March 2019 Steve and Kate question Steph Corbett about John Corbett’s NI connections12th March 2019 Ted Hastings visits Lee Banks at Blackthorn prison, John Corbett is murdered by Ryan Pilkington14th March 2019 Patricia Carmichael of AC-3 interviews Ted Hastings over his alleged corruption after he poses as ‘H’ in an unofficial undercover op which results in the arrest of Lisa McQueen and the death of Miroslav Minkowicz. Lisa later makes an immunity deal and gets witness protection. Gill Biggeloe is found to be corrupt, arrested, and also ends up under witness protectionLate March 2019 Operation Pear Tree is concluded, finding no link between police corruption and organised crime. God, give me strength!27th July 2019 Ryan Pilkington officially joins Central Police Line of Duty continues on Sunday the 25th of April at 9pm on BBC One.