Line of Duty: Season 4
Season 4 Lore Primer
Key plot threads, lore context, and character stakes you need to remember before diving into this season.
- Directly follows the overarching narrative developments of Line of Duty Season 3.
- Faction dynamics and core character alliances shift under escalating external stakes.
- Crucial mysteries introduced previously reach key turning points and narrative reckonings.
- Sets up serialized story arcs that build directly toward the climactic season finale.
Episode Guide
Season 4 Progress Shield
Episode 1
Mar 26, 2017
DCI Roz Huntley is under intense pressure from her superiors to apprehend a serial murderer after months of fruitless investigation.
Episode 2
Apr 2, 2017
AC-12 crank up their investigation into Operation Trapdoor. Kate makes progress in her undercover role.
Episode 3
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.
Episode 4
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.
Episode 5
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.
Episode 6
Apr 30, 2017
While Nick Huntley faces lengthy questioning, AC-12 remain convinced of Roz's involvement.