Line of Duty

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

AC-12 crank up their investigation into Operation Trapdoor. Kate makes progress in her undercover role.

AC-12 uncover holes in the case against Michael Farmer.

AC-12 interrogate Roz's husband Nick, but the discovery of new forensic anomalies puts the spotlight back on Roz.

Roz struggles to assuage her husband's suspicions, and AC-12 find a new angle to pursue in their case against her. Nick’s suspicions over his wife’s guilt continue to grow and a cold case gives AC-12 another way to challenge Roz.

While Nick Huntley faces lengthy questioning, AC-12 remain convinced of Roz's involvement.