Line of Duty - All Seasons

Steve Arnott is transferred to a Police Anti-Corruption Unit, where he finds his target is the city's top detective, Tony Gates.

AC-12 investigates the sole survivor of the attack on police convoy, escorting a civilian under a witness protection.

The new targets of the AC-12 investigation are Sgt. Danny Waldron and his team, who shoot dead a criminal, but cracks soon appear in their story. Are they covering up a murder? Meanwhile an old case develops a new angle.

When DCI Roz Huntley captures a serial killer, the chief forensic investigator alerts AC-12 to a possible miscarriage of justice.

AC-12 suspects corrupt cops are leaking information to a ruthless organized-crime boss who may be their most vicious adversary yet.

In series seven AC-12 has been disbanded and rebranded the Inspectorate of Police Standards. Anticorruption work has never been more difficult and in this challenging climate Steve Arnott, Kate Fleming and Ted Hastings are assigned their most sensitive case so far.

Detective Inspector Dominic Gough, a charismatic officer winning plaudits for a string of takedowns of organised crime, is accused of abusing his position of trust to act as a sexual predator. But is Gough's case a deliberate distraction from a bigger threat still operating in the shadows?