Line of Duty

A police anti-corruption unit known as AC-12 investigate DCI Joanne Davidson on suspicion of mishandling an inquiry into the murder of investigative journalist, Gail Vella.

AC-12 suspect a cover-up as they probe DCI Davidson's team for the officer sabotaging the inquiry into Gail Vella's murder.

Torn loyalties and criminal interference threaten to derail the investigation into Gail Vella's murder as well as AC-12's inquiry.

DCI Jo Davidson faces increasing pressure from all sides as AC-12 make major breakthroughs in the investigation, but an attempt to interview a key witness goes horribly wrong.

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.

As AC-12 struggle to deal with the repercussions of tragic events, Hastings makes one final bid to uncover institutionalized corruption before his time runs out.

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