Line of Duty: Series 4

Season overview

Role: Meticulous television and film archivist.
Task: Produce a JSON object for "Line of Duty" Season 4.
Keys: overview (160-220 words summary), primer (array of exactly 4 concise bullet points).
Constraints: Use ONLY provided synopsis and sources. No invented facts. No markdown/asterisks/headings/bullets in the prose (though primer is an array). Output valid JSON only.
Input: TMDB Synopsis and 5 Sources.
TMDB Synopsis: Season 4 features AC-12 facing a devious opponent. DCI Roz Huntley, under pressure from superiors, charges a young man with a series of murders after months of fruitless investigation. The Chief Forensic Investigator has doubts and turns to AC-12.
Source 1: Series is "Line of Duty (2012)", genre is Crime, Drama, and Mystery.
Source 2: Created by Jed Mercurio. Stars Martin Compston, Vicky McClure, Adrian Dunbar, Craig Parkinson. It follows elite detectives investigating police corruption.
Source 3: British police procedural/serial drama. Created by Jed Mercurio. Produced by World Productions for BBC. Started 26 June 2012.
Source 4: Detective Sergeant Steve Arnott transferred to AC-12 (anti-corruption unit) after a mistaken shooting during a counter-terrorist operation. Works alongside Detective Constable Kate Fleming.
Source 5: British crime drama.
Overview:
The fourth series of the British crime drama Line of Duty presents the anti-corruption unit AC-12 with a significant challenge as they encounter a devious opponent. The narrative focuses on DCI Roz Huntley, who, facing pressure from her superiors, moves to charge a young man with a series of murders following several months of investigation that yielded no results. This action raises questions regarding the guilt of the accused individual. The situation becomes more complex when the Chief Forensic Investigator expresses doubts about the case, leading them to seek assistance from the detectives at AC-12. As a police procedural created by Jed Mercurio, the series continues its exploration of elite detectives tasked with investigating police corruption. The team, which includes members such as Detective Sergeant Steve Arnott and Detective Constable Kate Fleming, must navigate the intricacies of this investigation to determine the truth behind the murders and the validity of the charges brought by Huntley. This season highlights the tension between investigative pressure and forensic uncertainty within the framework of the unit's mission to uncover misconduct.
Word Count Check (Overview):
"The fourth series of the British crime drama Line of Duty presents the anti-corruption