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Line of Duty

Season 4

6 listed hours · 2012–2021 · BBC

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From the desk

How this season is filed

Filed by Lana Reyes · Red Carpet Reality

Jed Mercurio's AC-12 interview rooms are gladiatorial: bent coppers, Hastings catchphrases, institutional rot that keeps climbing. British procedural paranoia as national event, scaled all the way to finale mania. Dialogue-heavy thriller craft — the anti-corruption unit as sport, and watercooler television that never needed a car chase.

TV Flash files Season 4 of Line of Duty (2012–2021) on BBC as a mid listed season (4; 4 of 6) — 6 listed hours, 2017-03-26–2017-04-30 from “Episode 1” (S04E01) to “Episode 6” (S04E06). Titles, dates, and synopses on file — no invented recaps.

Desk essentials in this season

  1. S04E01 Episode 1

    Season four opens the mania years: appointment interrogation rooms, Hastings catchphrases treated as civic liturgy.

  1. S04E01

    Episode 1

    After months of hunting a serial killer, DCI Roz Huntley faces intense pressure to apprehend a suspect. Michael Farmer is caught and charged with the crimes, but doubts about the young man's guilt lead the chief forensic investigator to AC-12. When DCI Roz Huntley captures a serial killer, Forensic Coordinator Tim Ifield alerts AC-12 to a possible miscarriage of justice.

  2. S04E02

    Episode 2

    A dismembered body is discovered, and worries grow when Roz fails to report for duty. After further questioning of Michael Farmer unearths crucial new information, AC-12 challenge the case against him. Meanwhile Arnott and Fleming continue to clash.

  3. S04E03

    Episode 3

    As shocking new evidence is unearthed, AC-12 step up their investigation in to the case against Michael Farmer. Could the real killer still be at large? Meanwhile, Detective Constable Jamie Desford joins the AC-12 team.

  4. S04E04

    Episode 4

    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.

  5. S04E05

    Episode 5

    AC-12's future hangs in the balance, after Hilton bars them from investigating Roz Huntley. But Roz's problems are building closer to home.

  6. S04E06

    Episode 6

    The explosive series finale pits AC-12 against Roz in a climactic duel to find Tim's murderer and unmask Balaclava Man.

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