AC-12 investigate DCI Jo Davidson's apparent mishandling of the murder of an investigative journalist. Show more
AC-12 suspect a cover-up as an officer on DCI Davidson's team appears to have sabotaged the inquiry into Gail Vella's murder. Show more
A new witness comes forward claiming to have crucial evidence in Gail Vella's murder. Kate is torn between her loyalty to Jo and to AC-12. Show more
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, but forces beyond their control threaten to derail the investigation. Show more
AC-12 struggle to come to terms with tragic events, redoubling their efforts to root out any remaining corrupt officers. Show more
AC-12 close in on 'H', the Fourth Man (or Woman) orchestrating the network of corrupt officers. Show more