The best episode of "Line of Duty" season 4 is "Episode 1", rated 8.4/10 from 1458 user votes. It was directed by Jed Mercurio and written by Jed Mercurio. "Episode 1" aired on 3/26/2017 and is rated 0.3 point(s) higher than the second highest rated, "Episode 2".
DCI Roz Huntley is under intense pressure from her superiors to apprehend a serial murderer after months of fruitless investigation.
Director: Jed Mercurio
Writer: Jed Mercurio
AC-12 crank up their investigation into Operation Trapdoor. Kate makes progress in her undercover role.
Director: Jed Mercurio
Writer: Jed Mercurio
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.
Director: John Strickland
Writer: Jed Mercurio
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.
Director: John Strickland
Writer: Jed Mercurio
DCI Roz Huntley struggles to allay her husband's suspicions. AC-12 find a new angle to pursue their case against her.
Director: John Strickland
Writer: Jed Mercurio
While Nick Huntley faces lengthy questioning, AC-12 remain convinced of Roz's involvement.
Director: John Strickland
Writer: Jed Mercurio