Line of Duty

Having been duped into covering up Jackies crime, Gates is desperate to sever ties with her. But, as Arnott and Fleming close in on his secret, Gates is plunged into an even more dangerous situation than he first thought.

Desperate for proof of Gatess corruption, Fleming pushes her relationship with him to the limit. But her behaviour causes Morton to question if she might not be such a loyal colleague after all.

A brutal ambush on a police convoy leaves three officers dead and a protected witness fighting for his life. AC-12 turn their spotlight on Lindsay Denton, the officer who led the convoy but escaped unscathed.

Lindsay is denied bail and finds herself targeted in prison. Growing increasingly desperate, she tells Kate about a relationship with an executive police officer and her theory of why she is being framed.

Lindsay fights for her life as troubling details emerge of a vicious conspiracy involving corrupt police officers. With growing evidence of links between DCC Dryden and the ambush, Hastings is under pressure to arrest his senior officer.

Sergeant Danny Waldron and his armed response team shoot dead a hardened criminal.

DS Steve Arnott believes there is a dark secret in Danny Waldrons past.

Loyalties are divided when DS Steve Arnott comes under scrutiny from his colleagues.

DCI Roz Huntley is under intense pressure from her superiors to apprehend a serial murderer after months of fruitless investigation.

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.

DCI Roz Huntley struggles to allay her husbands suspicions. AC-12 find a new angle to pursue their case against her.

Following the deadly hijack of a police convoy, AC-12 target a ruthless organised crime group known to have links with corrupt officers.

Corbetts most daring plan yet requires McQueen to exploit links with corrupt police officers.

As the hunt for H intensifies, Steve and Kate wonder if Hastings is guarding a dark secret.

DCI Jo Davidson receives new information about the whereabouts of a suspect in the unsolved murder of investigative journalist Gail Vella. En route to raid the property, she spots an armed robbery in progress and stops the convoy. Suspicious of her motives, AC-12 launch an investigation. Still dealing with the fallout from their explosive investigation into undercover officer John Corbett, AC-12 soon realise they are facing their most enigmatic adversary yet.

On the strength of evidence from a new witness, DCI Jo Davidson brings Terry Boyle back in for questioning about Gail Vellas murder. Kate is torn between loyalty to Jo and wanting to assist AC-12s investigation, and tensions increase when Kate encounters a face from the past with links to organised crime.

AC-12 link Gail Vella’s murder with a historic case of police corruption, and Kate hatches a plan to tell once and for all if Jo is bent. They are closer than ever to cracking the case, but when Hastings’ authority is undermined it leaves his team in a potentially dangerous situation.

With time running out, AC-12 attempt to unmask H, the Fourth Man (or Woman) commanding the network of corrupt officers behind the murder of Gail Vella. But sinister and powerful forces appear intent on orchestrating a cover-up.