Line Of Duty

AC-12 investigate DCI Jo Davidson's apparent mishandling of the murder of an investigative journalist.

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

A new witness leads to DCI Jo Davidson bringing Terry Boyle back in for questioning, while Kate is torn between loyalty to Jo and wanting to assist AC-12's investigation.

With a new suspect in their sights, AC-12 moves forward rapidly with their investigation.

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 corrupt.

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

With time running out, AC-12 attempt to unmask "H", but sinister and powerful forces appear intent on orchestrating a cover-up.